WO2000064864A1 - N-protected amines and their use as prodrugs - Google Patents

Abstract

Compounds of formula (I) or (II), wherein X represents H, C1-6 alkyl or C1-6 alkoxy, said alkyl or alkoxy being optionally substituted with one or more groups; a is 0,1,2,3 or 4; Y represents H or C1-6 alkyl; 1, 2 or 3 of the members Z of the 5-membered aromatic ring are independently selected from -O-, -S-, -N= or -NR-, where R is H or C1-6 alkyl optionally substituted with one or more of groups; and E represents a moiety such that EH is an amine; provided that in formula (I) if a = 0 then Y≠H, are provided along with a method of selecting desired protecting groups by measuring the fragmentation rates of compounds of formula (I) or (II) when the nitro group is selected.

Description

N-PROTECTED AMINES AND THEIR USE AS PRODRUGS

The present invention relates to methods and compounds for providing amines with N-protecting groups. It further relates to the protected amines themselves and their use as prodrugs.

The amines are protected as nitroaromatic carbamates (where "aromatic" includes "heteroaromatic"). They include nitro ormmc wⁱ „„„ „ ■ ^• to reduction, leading to loss of the protecting le is desirably

^"„AJ2-N0O- biologically active, the i protection. Thus it may be an amine-based ^ f« ^j-55 *r> <a " rP le, an aniline mustard or an enediyne.

Thus suitable pre QXtX agents, and/or may be useful as prodrugs for ADEPT) or gene-

Qc ^ directed enzyme prodrug reductase enzymes. BACKGROUND TO TH The use of prodrug ; converted into more active compounds in vivo) particularly in cancer therapy. For example a prodrug may be converted into an anti-tumour agent under the influence of an enzyme that is linkable to a monoclonal antibody that will bind to a tumour associated antigen. The combination of such a prodrug with such an enzyme monoclonal/antibody conjugate represents a very powerful clinical agent. This approach to cancer therapy, often referred to as "antibody directed enzyme/prodrug therapy" (ADEPT), is disclosed in WO88/07378.

A further therapeutic approach termed "virus-directed enzyme prodrug therapy" (VDEPT) has been proposed as a method for treating tumour cells in patients using prodrugs. Tumour cells are targeted with a viral vector carrying a gene encoding an enzyme capable of activating a prodrug. The gene may be transcriptionally regulated by tissue specific promoter or enhancer sequences. The viral vector enters tumour cells and expresses the enzyme, in order that a prodrug is converted to an active drug within the tumour cells (Huber et al, Proc. Natl. Acad. Sci. USA (1991) 88, 8039). Alternatively, non-viral methods for the delivery of genes have been used. Such methods include calcium phosphate co-precipitation, microinjection, liposomes, direct DNA uptake, and receptor-mediated DNA transfer. These are reviewed in Morgan & French, Annu. Rev. Biochem., 1993, 62; 191. The term "GDEPT" (gene-directed enzyme prodrug therapy) is used to include both viral and non-viral delivery systems.

4-Nitrobenzyl carbamates (A) undergo multi-electron reduction to produce amines. The mechanism probably involves the formation of electron-donating 4-hydroxylamine (B;Q=OH) or 4-amine (B;Q=H) species, which then fragment to generate a quinoneimine methide (C) and an amine (D) [P.L. Carl, P.K. Charkravarty, and J.A. Katzenellenbogen, J. Med. Chem., 1981, 24, 479].

Despite a low reduction potential (ca. -490 mV) [P. Wardman, Environ. Health Perspect., 1985, 64, 309] the 4-nitrobenzyl carbamate moiety undergoes facile reduction by the E. coli NR enzyme, and has been used as a prodrug "trigger" to deactivate highly cytotoxic amine "effectors" [M.P. Hay and W.A. Denny, Drugs Future,\996, 21, 917]. The E. coli enzyme has been shown to activate 4-nitrobenzyl carbamate derivatives of a limited number of amine-based cytotoxins, including actinomycin D and anthracyclines [A.B. Mauger, P.J. Burke, H.H. Somani, F. Friedlos and R.J. Knox, J. Med. Chem., 1994, 37, 3452], aniline mustards [A.B. Mauger, P.J. Burke, H.H. Somani, F. Friedlos and R.J. Knox, J. Med. Chem., 1994, 37, 3452; M. Lee, J.E. Simpson Jnr, S. Woo, C. Kaenzig, G.M. Anlezark, E. Eno-Amooquaye, and P.J. Burke, Bioorg. Med. Chem. Lett, 1997, 7, 1065] and enediynes [M.P. Hay, W.R. Wilson, and W.A. Denny, Bioorg. Med. Chem. Lett., 1995, 5, 2829]. All of these studies have used the otherwise unsubstituted 4-nitrobenzyl carbamate moiety.

To be fully effective, such prodrugs must be activated efficiently by the enzyme, and the resulting reduced species must fragment rapidly to release the cytotoxic amine effector. Kinetic structure-activity relationships (SAR) have been extensively studied for the one- electron reduction of nitrobenzyl halides [D.L. Kirkpatrick, K.E. Johnson, and A.C.

Sartorelli, J. Med. Chem., 1986, 29, 2048] and quaternary salts [M. Tercel, W.R. Wilson, R.F. Anderson, and W.A. Denny, J. Med. Chem., 1996, 39, 1084 and refs therein], but not for 4-nitrobenzyl carbamates. We have found that suitable substituents on the 4-nitrobenzyl ring and/or alpha-carbon result in more rapid fragmentation of the 4-hydroxylamine intermediates, and can also serve as sites for attaching solubilising functionalities. For a series of substituted 4-nitrobenzyl carbamate model compounds (X), fragmentation rates of the corresponding 4-hydroxylamines (Y) to release amines (Z) correlated with electron-donating properties (σ_p) of the substituent, as shown in Table 1. The maximum half-lives (Mt_I/2) of the hydroxylamine derivatives were measured by HPLC, following 4-fold stoichiometry radiolytic reduction of the corresponding substituted 4- nitrobenzyl carbamates. Assuming first order conditions, the half-life (t_1/2) of species R is calculated from the equation ln([Ry[R],) = t(ln2/t_1/2). The ratio [Ry[R]_r was taken as the fraction of nitrobenzyl carbamate which had not released the amine (Z) after 4-fold reduction. This method yields a maximum value for the half-life of fragmentation.

X(E = N0₂) Y (E = NHOH)

Table 1 Half-lives for fragmentation (Mt_1/2 ) and percent of amine released (t₀) for substituted 4-hydroxylaminobenzyl carbamates (derived from the corresponding 4- nitrobenzyl carbamates by radiolytic reduction).

Table 1 shows that the unsubstituted hydroxylaminobenzyl carbamate normally used as a trigger has a half-life of 16 minutes. This is relatively long and, under biological conditions, may result in substantial loss of material by side reactions not involving (activating) amine release. The half-life can be lowered significantly by the use of electron-donating substituents, and/or by the use of α-substituents (A). DISCLOSURE OF THE INVENTION

In a first aspect, the invention provides a method of providing an amine with a protecting group comprising (i) providing a plurality of different compounds selected from compounds of formulae (I) and (II)

wherein:

X represents H, C,.₆ alkyl or C,^ alkoxy, said alkyl or alkoxy being optionally substituted with one or more of the following groups: hydroxy (OH), ether (ORJ, amino (NH₂), mono-substituted amino (NR.Η), di-substituted amino (NR_^'R^²), cyclic C,._s alkylamino, imidazolyl, C,_₆ alkylpiperazinyl, morpholino, thiol (SH), thioether (SR_X), tetrazole, carboxy (COOH), carboxylate (COOR , sulphoxy (S(=O)₂OH), sulphonate (S(=O)₂OR_x), sulphonyl (S(=O)₂R_x), sulphixy (S(=O)0H), sulphinate (S(=O)OR_x), sulphinyl

where R,, R_x ¹ and R_χ ² are selected from a C,.₆ alkyl group, a C₃.₂₀ heterocyclyl group or a C₅.₂₀ aryl group, preferably a C,^ alkyl group; a is 0,1,2,3 or 4; Y represents H or C,.₆ alkyl; 1, 2 or 3 of the members Z of the 5-membered aromatic ring are independently selected from -O-,-S-,-N= or - NR-, (where R is H or C,.₆ alkyl optionally substituted with one or more of the following groups: hydroxy (OH), ether (OR_R), amino (NH₂), mono-substituted amino (NR_RH), di- substituted amino (NR_R'R_R ²), 0,-₅ cyclic amino, imidazolyl, alkylpiperazinyl, morpholino, thiol (SH), thioether (SR_R), tetrazole, carboxy (COOH), carboxylate (COOR_R), sulphoxy (S(=O)₂OH), sulphonate (S(=O)₂OR_R), sulphonyl (S(=O)₂R_R), sulphixy (S(=O)OH), sulphinate (S(=O)OR_R), sulphinyl (S(=O)R_R), phosphonooxy (OP(=O)(OH)₂) and phosphate (OP(=O)(OR_R)₂), where R_R, R_R' and R_R ² are selected from a C,.₆ alkyl group, a C₃.₂₀ heterocyclyl group or a C₅.₂₀ aryl group, preferably a C,.₆ alkyl group), the other ring atoms being C; n is 0 or 1; and E represents a moiety such that EH is an amine; (ii) measuring the rates of fragmentation of the compounds to release EH when the nitro group is reduced and selecting a compound having a desired rate of decomposition; and (iii) providing the amine to be protected with a protecting group corresponding to that in the selected compound.

In this aspect, the step of selecting the compound is preferably carried out in order to provide a protecting group with a faster rate of fragmentation than unsubstituted 4-nitrobenzyl carbamate. However selecting a compound bearing a protecting group with a slower rate of fragmentation than 4-nitrobenzyl carbamate may be preferred. This particularly applies in situations in which it is desired to provide a prodrug which can diffuse away from the site of actuation by the appropriate enzyme, and thus kill tumour cells further away from the site of actuation (the "bystander" effect).

In a second aspect, the present invention relates to a compound represented by the general formula (I) or (II) as shown above, wherein X, Y, Z, E, a and n are as defined above; provided that in formula (I) if a = 0 then Y ≠ H.

EH is preferably a cytotoxic amine. E may be selected from formulae (III-XIII). In (III-XIII), R, represents H or C,^ alkyl, being optionally substituted with one or more of the following groups: one or more of the following groups: hydroxy (OH), ether (OR_E), amino (NH₂), mono-substituted amino (NR_EH), di-substituted amino (NR_E'R_E ²), cyclic C,_.5 alkylamino, imidazolyl, C,.₆ alkylpiperazinyl, morpholino, thiol (SH), thioether (SR_E), tetrazole, carboxy (COOH), carboxylate (COOR_E), sulphoxy (S(=O)₂OH), sulphonate (S(=O)₂OR_E), sulphonyl (S(=O)₂R_E), sulphixy (S(O)OH), sulphinate (S(=O)OR_E), sulphinyl (S(=O)R_E), phosphonooxy (OP(=O)(OH)₂) and phosphate (OP(=O)(OR_E)₂), where R_E, R_E' and R_E ² are selected from a C,_₆ alkyl group, a C₃.₂₀ heterocyclyl group or a C₅.₂₀ aryl group, more preferably from a C,_₆ alkyl group ; R₂ represents H, C,.₆ alkyl, C,.₆ alkoxy, OH, halogen, NO₂, NH₂, NHMe, NMe₂, SO₂Me, CF₃, CN, CONH₂ or CONHMe; each R₃ is independently selected from Cl, Br, I and OMS; and R₄ is selected from -C(=O)Me and -C(=O)CH₂OH; Q represents substituted indole, substituted benzofuran or substituted cinnamoyl; in (IX) and (X), each n is independently from 2-4, and each m is independently from 2-4, and p = 0 or 1.

Compounds of formula V are described in EP 0 938 474, which is incorporated herein by reference. Compounds of formula VI are described in EP 0 850 220, which is incorporated herein by reference.

A compound of formula (I) or (II) may be basic or acidic and may thus form pharmaceutically acceptable salts with both organic and inorganic acids and bases. These are included within the scope of the second aspect.

In a first type of preferred embodiment, X represents C,.₆ alkyl or C,.₆ alkoxy, said alkyl or alkoxy being optionally substituted with one or more of the following groups: hydroxy, ether (ORJ, amino, alkylamino (NRχH), dialkylamino (NR -R^), cyclic C,_.5 alkylamino, imidazolyl, C,.₆ alkylpiperazinyl, morpholino, thiol, alkylthioether (SRJ, tetrazole and -CO₂X' where X' is selected from the possibilities listed for X and R^ -R^¹ and R_x ² are selected from C,_₆ alkyl; a is 0,1,2,3 or 4; Y represents H or lower alkyl; 1, 2 or 3 of the members Z of the 5-membered aromatic ring are independently selected from -O-,-S-,-N= or - NR-, (where R is H or lower alkyl optionally substituted with one or more of the following groups: hydroxy, ether (OR_R), amino, alkylamino (NR_RH), dialkylamino (NR_R R_R ²), cyclic C,_.5 alkylamino, imidazolyl, C,_₆ alkylpiperazinyl, morpholino, thiol, alkylthioether (SR_R), tetrazole and -CO₂R' where R' is selected from the possibilities listed for R and R_R, R_R ^J and R_R ² are selected from C,.₆ alkyl); and E represents R, represents H or C,^ alkyl, being optionally substituted with one or more of the following groups hydroxy, ether (OR_E), amino, alkylamino (NR_EH), dialkylamino (NR^R,,²), cyclic C,.₅ alkylamino, imidazolyl, C,^ alkylpiperazinyl, moφholino, thiol, alkylthioether (SR_E), tetrazole and -CO₂X' where X' is selected from the possibilities listed for X and R_E, R_E' and R_E ² are selected from C alkyl.

In a second type of preferred embodiment, the compound is of formula (I) where a is 1. It is further preferred in this embodiment that X represents optionally substituted C,^ alkoxy and more preferably in the 2 position. The alkoxy group is preferably selected from methyl, ethyl and n-propyl, and the substituents from hydroxy, methoxy, phosphonoxy, NMe₂, Nmoφh, OCO₂-tBu, and OCO₂H. In more preferred embodiments the ethyl or n-propyl group is singly substituted, most preferably with hydroxy, whereas the Me group is unsubstituted. In this type of embodiment Y is preferably selected from H or Me. E is preferably selected from III - XIII, most preferably V or XIII. If E is selected from XIII, n is preferably 1.

In a third preferred type of embodiment, the compound is of formula (II) with one Z being -N= and another Z being -NR-, R being preferably Me or Et, the other members of the heterocyclic ring being C. If R is Et, it is preferably substituted with hydroxy. A is preferably 0. More preferably the -N= and -NR- are not adjacent in the heterocyclic ring. The most preferred arrangement is 2 (-NMe-) and 5 (-N=) , with the NO₂ at the 3 position. In this type of embodiment, Y is preferably selected from H or Me. E is preferably selected from V or XIII. If E is selected from XIII, than n is preferably 1.

In a fourth preferred type of embodiment, the compound is of formula (II), a is 0, and Z is either O or S. It is further preferred that the O or S is in the 2 position in the ring, and the NO₂ is attached to the 3 position. In this type of embodiment, Y is preferably selected from H or Me.

In a fifth preferred embodiment, the compound is of formula (II), and Z is NR, preferably NMe. There may be one further substituent (a=l), or there may be no further substituents on the ring (a=0). The further substituent is preferably CO₂Et. In this type of embodiment, Y is preferably selected from H or Me. In a third aspect the invention provides a compound according to the second aspect for pharmaceutical use.

In a fourth aspect the invention provides the use of a compound according to the second aspect for the manufacture of a composition for use in the treatment of a hyper- proliferative disease, particularly a neoplastic disease. The composition may also include activating means for simultaneous or separate administration, the activating means typically comprising an enzyme or means for providing an enzyme, for performing ADEPT or VDEPT therapy. The activating means typically leads to liberation of the amine EH.

In a fifth aspect the invention provides a compound of the formula XVI or XVII where X, n, Z and Y are as defined for the second aspect and T is OH or an activated alcohol functionality (such as -O.CO.L where L is a leaving group such as Cl) suitable for reaction with an amine EH to produce a compound according to the second aspect.

In a sixth aspect the invention provides the use of a compound of formula (XVI) or

(XVII) in protecting an amine. This may include activation of an alcohol (XVI or XVII where T is OH) with a reagent such as phosgene, diphosgene or triphosgene or a chloroformate, e.g. 4-nitrophenylchloroformate or pentafluorophenylchloroformate, optionally in conjunction with HOBT(l -hydroxybenzotriazole).

In a further aspect, the present invention relates to a method of preparing compounds of the general formula (I); examples of the methods are outlined in Schemes 1-24.

Thus (Scheme 1), reaction of the amine 7 [D-F. Shi, T. D. Bradshaw, S. Wrigley, C. J. McCall, P. Lelieveld, I. Fitchner, M. F. G. Stevens. J. Med. Chem., 1996, 39, 3375] with 4- nitrobenzylchloroformate gave carbamate 8.

Reagents: ( 4-nitrobenzylchbrofo-τr-ate, pyridine. 8

Reaction of the l,4-difluoro-5,8-dihydroxyanthracene-9,10-dione 22 with amine 15 in pyridine gave the monocarbamate 23 and biscarbamate 24 (Scheme 7). Further reaction of 23 with 2-(2- aminoethylamino)ethanol gave carbamate 26. In another example (Scheme 2), 4-nitrosalicylic acid (27) was methylated using a solution of diazomethane in ether and the methyl ester 28 reduced with DIB ALH in THF to give the nitrobenzyl alcohol 29. Activation of the alcohol 29 with triphosgene (or alternatively phosgene or diphosgene) in the presence of pyridine, and reaction with NⁱN -bis(2- hydroxyethyl)-l,4-benzenediamine (57) gives the carbamate 31, which was elaborated to the mustard 32 using standard methods. Scheme 2

Similarly (Scheme 3), activation of alcohol 29 with triphosgene in the presence of pyridine and reaction with amine 33 [M. Tercel and W. A. Denny. J. Chem. Soc. Perkin Trans. 1, 1998, 509] or amine 1 [G. J. Atwell, W. R. Wilson, W. A. Denny, Bioorg. Med. Chem. Lett., 1997, 7, 1483] gave carbamates 34 and 35, respectively.

Similarly (Scheme 4), activation of alcohol 29 with triphosgene in the presence of pyridine and reaction with amine 7 [D-F. Shi, T. D. Bradshaw, S. Wrigley, C. J. McCall, P. Lelieveld, I. Fitchner, M. F. G. Stevens. J. Med. Chem., 1996, 39, 3375] ] gave carbamate 36. Scheme 4

RHN-

S^' 7 R = H

(i)

36 R = CO₂CH₂(2-OMe)Ph-4-N0₂ Reagents (i) triphosgene, 29, pyπdne.

In another example (Scheme 5), activation of alcohol 29 with 4- nitrophenylchloroformate gave the carbonate 37 which was reacted with doxorubicin (13) and triethylamine in DMF to give the doxorubicin carbamate 38.

In another example (Scheme 6), carbonate 37 was coupled to amine 9 using 1- hydroxybenzotriazole (HOBT), 4A molecular sieves and triethylamine to give protected carbamate 39. Removal of the TBDMS protecting group with aqueous acid gave the alcohol 40 which was activated with 4-nitrophenylchloroformate to give the carbonate 41. Reaction of 41 with doxorubicin (13) and triethylamine in DMF gave the carbamate 42.

Reagents: (i) HOBT, moL sieves, Et₃N, THF; (ii) HCI, aq. MeOH; (iii) N0₂PhOCOCI, Et₃N, THF; (K, ) DOX, Et₃N, DMF.

In another example (Scheme 7), reaction of alcohol 29 with triphosgene and triethylamine, and coupling to 2,2,2-trifluoro-N-[2-(methylamino)ethyl]acetamide trifluoroacetate gave the trifluoroacetamide 43 which was deprotected under basic conditions to give amine 44. Activation of the 5-methyl-9-oxo-9,10-dihydro-4-acridinecarboxylic acid (16) with thionyl chloride and coupling of the intermediate 9-chloroacridinyl acid chloride with amine 44 gave amide 45 which was converted to carbamate 46 using ammonia in phenol.

45 R = CI 46 R = NH₂ (")

Reagents: (i) triphosgene, CF-CONHCH-CH-NHMe, DIEA; (ii) Cs₂C0₃; (iii) SOCI₂, DMF; (iv) PhOH, NH₃. In another example (Scheme 8), the bistrifluoroacetamide 47 was coupled to alcohol 29 to give bisamide 48 which was deprotected under basic conditions to give the amine 49. The amine 49 was coupled to 4-(lH-imidazol-l-ylcarbonyl)-5-methylacridine (50) [S. A. Gamage, J. A. Spicer, G. J. Atwell, G. J. Finlay, B. C. Baguley, W. A. Denny, J. Med. Chem., 1999, 42, 2383-2393] to give the carbamate 51.

Reaction of the l,4-difluoro-5,8-dihydroxyanthracene-9,10-dione 22 with amine 44 gave the monocarbamate 52 and biscarbamate 53 (Scheme 9). Further reaction of 52 with 2-(2- aminoethylamino)ethanol gave carbamate 55.

Reagents (ή 44, pyridine, (ϊ) NH₂(CH₂>2NH(CH₂)₂OH, pyridine

In another example (Scheme 10), reaction of 4-nitrophenylethan-l-ol (56) with triphosgene and pyridine, with the subsequent addition of N¹N¹-bis(2-hydroxyethyl)-l,4- benzenediamine (57) gave the carbamate 58 which was elaborated to the dichloride 59.

Scheme 10

Reagents (i) triphosgene, THF, (ii) MsCI, pyridine, ( i) LiCI, DMF

In another example (Scheme 11), coupling of the alcohol 56 with amine 1 [G. J. Atwell, W. R. Wilson, W. A. Denny, Bioorg. Med. Chem. Lett., 1997, 7, 1483] using triphosgene and pyridine in THF gave the carbamate 60.

Oxidation of alcohol 29 with pyridinium chlorochromate (PCC) in DCM gave the aldehyde 61 (Scheme 12). Reaction of aldehyde 61 with methyl magnesium bromide in THF gave the alcohol 62 which was coupled to amine 57 to give carbamate diol 63. The diol 63 was elaborated to the dichloride 64 using standard methods.

In another example (Scheme 13), alkylation of methyl 2-hydroxy-4-nitrobenzoate 66 with bromide 65 under basic conditions gave the ester 67 which was reduced to alcohol 68 using DIBALH in THF. Activation of amine 1 [G. J. Atwell, W. R. Wilson, W. A. Denny, Bioorg. Med. Chem. Lett., 1997, 7, 1483] with triphosgene and triethylamine gave an intermediate isocyanate which was coupled with alcohol 68 using catalytic dibutyltin diacetate to give carbamate 69. Deprotection of 69 under acidic conditions gave 70.

Scheme 13

Reagents: (i) 65, K₂C0₃, DMF; (ii) DI BALH, THF; (ii) 1, triphosgene, Et₃N, 69 R = TBDMS _) (iv) DCM, then 68, nBu₂Sn(OAc)₂; ( ) HCI, MeOH. 70 R = H > ' Similarly (Scheme 14), reaction of phenol 66 with 2-bromoethyl methyl ether gave ester 71 which was reduced to alcohol 72. Activation of amine 1 [G. J. Atwell, W. R. Wilson, W. A. Denny, Bioorg. Med. Chem. Lett., 1997, 7, 1483] with triphosgene and triethylamine gave an intermediate isocyanate which was coupled with alcohol 72 using catalytic dibutyltin diacetate to give carbamate 73.

Scheme 14

Reagents (i) BrCH₂CH₂OMe, K₂C0₃, DMF, (ii) DIBALH, THF, (in) 1, triphosgene, Et₃N, DCM, then 72, nBu₂Sn(0Ac)₂

In another example (Scheme 15), phenol 66 was alkylated with 3-iodopropyl tetrahydropyranyl ether under basic conditions to give ester 74 which was reduced to alcohol 75 using DIBALH in THF. Activation of the alcohol 75 with triphosgene and triethylamine (or pyridine, or another organic base) in THF and subsequent reaction with amine 57 gave the carbamate diol 76. The diol 76 was converted to the dichloride 77 using standard methods and the tetrahydropyranyl ether deprotected under acidic conditions to give carbamate 78.

Reagents (i) BιCH₂CH₂CH₂OTHP, K-CO- , DMF, (ii) DIBALH, THF, (ii) triphosgene, Et₃N, THF, then 57, (iv) MsCI, pyridine, (v) UCI, DMF, (vi) HCI, MeOH

76 R₁ = 0H, R₂ = THP^. (_IV), (v)

77 R, = α, R- = THP

78 R_! = Q, R- = H > (vι) In another example (Scheme 16), alcohol 75 was activated using triphosgene and triethylamine (or pyridine, or another organic base) and coupled to amine 33 [M. Tercel and W. A. Denny. J. Chem. Soc. Perkin Trans. 1, 1998, 509] to give carbamate 79 which was deprotected under acidic conditions to give 80.

In another example (Scheme 17), alkylation of phenol 66 with 3-bromopropyl tβrt- butyl(dimethyl)silyl ether under basic conditions gave the ester 81 which was reduced to alcohol 82 using DIBALH in THF. Activation of amine 1 [G. J. Atwell, W. R. Wilson, W. A. Denny, Bioorg. Med. Chem. Lett., 1997, 7, 1483] with triphosgene and triethylamine gave an intermediate isocyanate which was coupled with alcohol 82 using catalytic dibutyltin diacetate to give carbamate 83. Deprotection of 83 under acidic conditions gave carbamate 84.

In another example (Scheme 18), activation of alcohol 75 with 4- nitrophenylchloroformate gave the carbonate 37 which was deprotected under acidic conditions to give carbonate 86. Reaction of 86 with doxorubicin (13) and triethylamine in DMF gave the doxorubicin carbamate 87.

In another example (Scheme 19) alcohol 75 was activated with triphosgene and coupled to amine 47 to give trifluoroacetamide 88 which was deprotected under basic conditions to give bis-amine 89. Coupling of the bis-amine 89 with the imidazolide 50 [S. A. Gamage, J. A. Spicer, G. J. Atwell, G. J. Finlay, B. C. Baguley, W. A. Denny, J. Med. Chem., 1999, 42, 2383-2393] gave the carbamate 90 which was deprotected under acidic conditions to give carbamate 91.

In another example (Scheme 20), the alcohol 84 was reacted with di-tert-butyl diethylphosphoramidite and tetrazole inTHF and the intermediate oxidised with MCPBA to give ester 92. Deprotection of 92 with trifluoroacetic acid (TFAA) gave the phosphate 93.

In another example (Scheme 21), phenol 66 was alkylated with epichlorohydrin under basic conditions to give epoxide 94. Hydrolysis of 94 with perchloric acid gave diol 95 which was protected as the acetonide 96. Reduction of 96 with DIBALH in THF gave the alcohol 97. Activation of amine 1 [G. J. Atwell, W. R. Wilson, W. A. Denny, Bioorg. Med. Chem. Lett., 1997, 7, 1483] with triphosgene and triethylamine gave an intermediate isocyanate which was coupled with alcohol 97 using catalytic dibutyltin diacetate to give carbamate 98. Deprotection of 98 under acidic conditions gave carbamate 99.

Reagents (i) eptchbrohydπn, K₂C0₃, DMF, (i) HC10₄,THF, (ni) d-methoxyacetone, PPTS, DMF, (iv) DIBALH, THF, (v) 1 , tπphosgene, Et₃N, DCM then 97, nBu₂Sn(OAc)2, (vi) HCI, aq THF

In another example (Scheme 22), ), phenol 66 was alkylated with N-(3-chloropropyl)- NN-dimethylamine under basic conditions to give amine 100. Reduction of 100 with DIBALH in THF gave the alcohol 101. Activation of amine 1 [G. J. Atwell, W. R. Wilson, W. A. Denny, Bioorg. Med. Chem. Lett., 1997, 7, 1483] with triphosgene and triethylamine gave an intermediate isocyanate which was coupled with alcohol 101 using catalytic dibutyltin diacetate to give carbamate 102.

Similarly (Scheme 22), phenol 66 was alkylated with 4-(3-chloropropyl)morpholine under basic conditions to give amine 103. Reduction of 103 with DIBALH in THF gave the alcohol 104. Activation of amine 1 [G. J. Atwell, W. R. Wilson, W. A. Denny, Bioorg. Med. Chem. Lett., 1997, 7, 1483] with triphosgene and triethylamine gave an intermediate isocyanate which was coupled with alcohol 104 using catalytic dibutyltin diacetate to give carbamate 105.

In another example (Scheme 23), reaction of alcohol 91 with methanesulphonyl chloride gave the mesylate 106 which was reacted with morpholine to give carbamate 107.

In another example (Scheme 24), phenol 66 was alkylated with tert-butyl 4- bromobutanoate under basic conditions to give ester 108. Hydrolysis of 108 under basic conditions gave acid 109 which was reduced with borane.dimethylsufide in THF to give alcohol 110. Activation of alcohol 110 with triphosgene and diisopropylethylamine and subsequent coupling with NN-bis[3-(5-methylacridine-4-carboxamido)propyl]amine (111) [S. A. Gamage, J. A. Spicer, G. J. Atwell, G. J. Finlay, B. C. Baguley, W. A. Denny, J. Med. Chem., 1999, 42, 2383-2393] gave carbamate 112. Carbamate 112 was deprotected under acidic conditions to give acid 113.

Scheme 24

In a further aspect, the present invention relates to a method of preparing compounds of the general formula (II); examples of the methods are outlined in Schemes 25-.

Thus (Scheme 25), (2-nitro-lH-imidazol-5-yl)methanol (115) is obtained from the known ethyl 2-nitro-lH-imidazol-5-ylcarboxylate (113) [B. Cavalleri, R. Ballotta, G.C Lancini. J. Heterocyclic Chem. 1972, 9, 979.] by basic hydrolysis to the acid 114 and reduction of an intermediate imidazolide with sodium borohydride. This procedure is a major improvement upon the above published methods. Reaction of 115 with 4-nitrophenyl chloroformate gives the activated carbonate 116 which reacts with NN-bis-(2- chloroethyl)amine to give carbamate 117.

Scheme 25

Similarly (Scheme 26), reaction of 116 with the protected phenyldiamine diol 120, derived from the nitrophenylamino diol 118, gives carbamate 121. Deprotection of the bis-silyl alcohol 121 with TBAF gives the diol 122 which can be converted to the dichloride 123 under standard conditions.

Scheme 26

DMS

In another example (Scheme 27), activation of amine 1 [G. J. Atwell, W. R. Wilson, W. A. Denny, Bioorg. Med. Chem. Lett., 1997, 7, 1483] with triphosgene and triethylamine (or pyridine, or another organic base) gave an intermediate isocyanate which was coupled with alcohol 115 using catalytic dibutyltin diacetate to give carbamate 124.

In another example (Scheme 28), reaction of the carbonate 116 with doxorubicin (13) and triethylamine in DMF gave the carbamate 125.

Similarly (Scheme 29), reaction of carbonate 116 with amine 9 using HOBT, molecular sieves, and triethylamine gave the silyl ether 126. Deprotection of silyl ether 126 under acidic conditions gave alcohol 127 which was reacted with 4-nitrophenyl chloroformate to give carbonate 128. Reaction of the carbonate 128 with doxorubicin (13) and triethylamine in DMF gave the carbamate 129.

Reagents: (i) 9, HOBT, Et₃N, mol. sieves, THF; (ii) HCI. aq. MeOH; (iϋ) 4-N0₂PhOCOCI, THF; (vi) 13, Et₃N, DMF.

In another example (Scheme 30), ozonolysis of the styrene 130 [D. C. Baker, S. R. Putt, H. D. H. Showalter, J. Heterocyclic Chem., 1983, 30, 629-634.] gave the alcohol 131. Activation of amine 1 [G. J. Atwell, W. R. Wilson, W. A. Denny, Bioorg. Med. Chem. Lett., 1997, 7, 1483] with triphosgene and triethylamine gave an intermediate isocyanate which was coupled with alcohol 131 using catalytic dibutyltin diacetate to give carbamate 132.

Reagents (i) 0₃, DCM, MeOH, (ii) NaBH₄, EtOH, (iii) 1 , triphosgene, Et₃N, DCM, then 131, nBu-Sn(OAc)₂

In another example (Scheme 31), treatment of (N-methyl-5-nitro-lH-imidazol-2- yl)methanol (133) [C. Rufer, Η. J. Kessler, E. Schroder. J. Med. Chem. 1971, 14, 94.] with 4- nitrophenylchloroformate gave the carbonate 134, which was displaced with NN-bis(2- chloroethyl)amine to give the carbamate 135.

Scheme 31

Similarly (Scheme 32), activation of 133 with diphosgene and subsequent reaction withN^,Nⁱ-bis(2-chloroethyl)-l,4-benzenediamine hydrochloride (136) gave the carbamate 137. Sche

133 137

Reagents (i) diphosgene, EtsN, THF, (ϊ) 136, pyridine

In another example (Scheme 33), activation of amine 1 [G. J. Atwell, W. R. Wilson, W. A. Denny, Bioorg. Med. Chem. Lett., 1997, 7, 1483] with triphosgene and triethylamine gave an intermediate isocyanate which was coupled with alcohol 133 using catalytic dibutyltin diacetate to give carbamate 138.

In another example (Scheme 34), reaction of carbonate 134 with amine 9 using HOBT, molecular sieves, and triethylamine gave the silyl ether 139. Deprotection of silyl ether 139 under acidic conditions gave alcohol 140 which was reacted with 4-nitrophenyl chloroformate to carbonate 141. Reaction of the carbonate 141 with doxorubicin (13) and triethylamine in DMF gave the carbamate 142.

Reagents (i) 9, HOBT, Et₃N, mol sieves, THF, (ii) HCI, aq MeOH, 4-N0₂PhOCOCI, THF, (vi) 13, Et₃N, DMF

In another example (Scheme 35), condensation of metronidazole (143) and benzaldehyde gave the styrene 144 which was protected with TBDMS triflate to give 145. Ozonolysis of styrene 145 gave alcohol 146. Activation of amine 1 [G. J. Atwell, W. R. Wilson, W. A. Denny, Bioorg. Med. Chem. Lett., 1997, 7, 1483] with triphosgene and triethylamine gave an intermediate isocyanate which was coupled with alcohol 146 using catalytic dibutyltin diacetate to give carbamate 147. Deprotection under acidic conditions gave the carbamate 148.

Reagents (i) NaOMe, PhCHO, DMSO, (i) TBDMSTf, pyridine, DCM, 147 R = TBDMS \ /_V

148 R = H * ' (ii) 0₃, DCM, MeOH, (vi) NaBH₄, EtOH, (v) 1, triphosgene, Et₃N, DCM, then 146, nBu-Sn(OAc)₂, (vi) HCI, aq MeOH Similarly (Scheme 36), activation of amine 1 [G. J. Atwell, W. R. Wilson, W. A. Denny, Bioorg. Med. Chem. Lett., 1997, 7, 1483] with triphosgene and triethylamine gave an intermediate isocyanate which was coupled with alcohol 149 [D. C. Baker, S.R. Putt, H. D. H. Showalter, J. Heterocyclic Chem., 1983, 20, 629-634.] using catalytic dibutyltin diacetate to give carbamate 150.

In another example (Scheme 37), reaction of the 5-nitrofuran-l-methanol (151) [J. M.

Berry, C. Y. Watson, W. J. D. Whish, and M. D. Threadgill, J. Chem. Soc. Perkin Trans. I, 1997, 1147.] with 4-nitrophenylchloroformate gave carbonate 152, which was displaced with N¹Nⁱ-bis(2-hydroxyethyl)-l,4-benzenediamine (57) to give the carbamate diol 153. The diol 153 was converted to the dichloride 154 using standard methods. Similarly (Scheme 37), reaction of (5-nitrothien-2-yl)methanol (156) [P. J.

Narcombe, R. K. Norris. Aust. J. Chem. 1979, 32, 2647] with 4-nitrophenylchloroformate gave carbonate 157, which was displaced withN¹N¹-bis(2-hydroxyethyl)-l,4-benzenediamine (57) to give the carbamate diol 158. The diol 158 was converted to the dichloride 159 using standard methods. The same technique was used on 5-nitrofuran-l-methanol (151) [J.M. Berry, C.Y. Watson, W.J. Whish, and M.D. Threadgill, J. Chem. Soc. Perkin Trans. 1, 1997, 1147].

153 χ = 0, R = OH

Reagents (i) N0₂PhOCOCI, pyridine, THF

154 X = O, R = α (i) 57, pyridine, (ii) (a) MsCI, pyπdne, (^■')

158 X = S, R = OH (b) LCI, DMF 159 χ = S, R = CI

In another example (Scheme 38), activation of amine 1 [G. J. Atwell, W. R. Wilson, W. A. Denny, Bioorg. Med. Chem. Lett., 1997, 7, 1483] with triphosgene and triethylamine gave an intermediate isocyanate which was coupled with alcohol 151 [J. M. Berry, C. Y. Watson, W. J. D. Whish, and M. D. Threadgill, J. Chem. Soc. Perkin Trans. 1, 1997, 1147.] using catalytic dibutyltin diacetate to give carbamate 155.

Similarly (Scheme 38), activation of amine 1 [G. J. Atwell, W. R. Wilson, W. A. Denny, Bioorg. Med. Chem. Lett., 1997, 7, 1483] with triphosgene and triethylamine gave an intermediate isocyanate which was coupled with alcohol 156 [P. J. Narcombe, R. K. Norris. Aust. J. Chem. 1979, 32, 2647] using catalytic dibutyltin diacetate to give carbamate 160.

In another example (Scheme 39), l-methyl-5-nitro-lH-pyrazole-4-carboxylic acid (161) [C. C. Cheng, J. Heterocyclic Chem. 1968, 5, 195-197] was reduced with borane.dimethyl sulfide to give alcohol 162. Activation of amine 1 [G. j. Atwell, W. R. Wilson, W. A. Denny, Bioorg. Med. Chem. Lett., 1997, 7, 1483] with triphosgene and triethylamine gave an intermediate isocyanate which was coupled with alcohol 162 using catalytic dibutyltin diacetate to give carbamate 163.

Scheme 39

In another example (Scheme 40), ethyl 4-formyl-5-nitro-lH-pyrrole-2-carboxylate (164) [P. Fornari, M. Famier, C. Fournier, Bull. Soc. Chim. Fr. 1972, 283-291] was alkylated with dimethyl sulfate to give pyrrole 165. Reduction of 165 with sodium borohydride gave the alcohol 166. Activation of amine 1 [G. J. Atwell, W. R. Wilson, W. A. Denny, Bioorg. Med. Chem. Lett., 1997, 7, 1483] with triphosgene and triethylamine gave an intermediate isocyanate which was coupled with alcohol 166 using catalytic dibutyltin diacetate to give carbamate 167.

In another example (Scheme 40), hydrolysis of ester 166 followed by decarboxylation with copper in quinoline gave alcohol 168. Activation of amine 1 [G. J. Atwell, W. R. Wilson, W. A. Denny, Bioorg. Med. Chem. Lett., 1997, 7, 1483] with triphosgene and triethylamine gave an intermediate isocyanate which was coupled with alcohol 168 using catalytic dibutyltin diacetate to give carbamate 169.

Similarly (Scheme 41), ethyl 5-formyl-4-nitro-lH-pyrrole-2-carboxylate (170) [P. Fornari, M. Farnier, C. Fournier, Bull. Soc. Chim. Fr. 1972, 283-291] was alkylated with dimethyl sulfate to give pyrrole 171. Reduction of 171 with sodium borohydride gave the alcohol 172. Activation of amine 1 [G. J. Atwell, W. R. Wilson, W. A. Denny, Bioorg. Med. Chem. Lett., 1997, 7, 1483] with triphosgene and triethylamine gave an intermediate isocyanate which was coupled with alcohol 172 using catalytic dibutyltin diacetate to give carbamate 173.

In another example (Scheme 41), hydrolysis of ester 172 followed by decarboxylation with copper in quinoline gave alcohol 174. Activation of amine 1 [G. J. Atwell, W. R. Wilson, W. A. Denny, Bioorg. Med. Chem. Lett., 1997, 7, 1483] with triphosgene and triethylamine gave an intermediate isocyanate which was coupled with alcohol 174 using catalytic dibutyltin diacetate to give carbamate 175.

In another example (Scheme 42), l-methyl-5-nitro-lH-pyrrole-2-carbaldehyde (176) [ P. Fournari, Bull. Soc. Chim. Fr. 1963, 488-491] was reduced with sodium borohydride to give alcohol 177. Activation of amine 1 [G. J. Atwell, W. R. Wilson, W. A. Denny, Bioorg. Med. Chem. Lett., 1997, 7, 1483] with triphosgene and triethylamine gave an intermediate isocyanate which was coupled with alcohol 177 using catalytic dibutyltin diacetate to give carbamate 178.

In a further preferred aspect, the present invention relates to the use of a compound of formula (I) or (II) as defined in the second aspect of the invention, in conjunction with a nitroreductase enzyme (for example, isolated from E. coli) in a method of ADEPT or GDEPT therapy. A drug produced by the action of the nitroreductase enzyme on a compound of formula (I) or (II) may be used for the selective killing of oxic and hypoxic tumour cells in methods of treatment of cancers, for example leukemias and particularly solid cancers including breast, bowel and lung tumours, including small cell lung carcinoma. The invention also provides a pharmaceutical composition comprising a compound of the formula (I) or (II) as defined in the second aspect of the invention together with a pharmaceutically acceptable carrier or diluent. Detailed Description of the Invention GDEPT - Vector systems

In general, the vector for use in GDEPT therapies may be any suitable DNA or RNA vector.

Suitable viral vectors include those which are based upon a retrovirus. Such vectors are widely available in the art. Huber et al. (ibid) report the use of amphotropic retroviruses for the transformation of hepatoma, breast, colon or skin cells. Culver et al. (Science (1992) 256; 1550-1552) also describe the use of retroviral vectors in GDEPT. Such vectors or vectors derived from them may also be used. Other retroviruses may also be used to make vectors suitable for use in the present invention. Such retroviruses include rous sarcoma virus (RSV). Englehardt et al. (Nature Genetics (1993) 4; 27-34) describe the use of adenovirus based vectors in the delivery of the cystic fibrosis transmembrane conductance product (CFTR) into cells, and such adenovirus based vectors may also be used. Vectors utilising adenovirus promoter and other control sequences may be of use in delivering a system according to the invention to cells in the lung, and hence useful in treating lung tumours.

Other vector systems including vectors based on the Molony murine leukaemia virus are known (Ram, Z et al. Cancer Research (1993) 53; 83-88; Dalton & Treisman, Cell (1992) 68; 597-612). These vectors contain the Murine Leukaemia virus (MLV) enhancer cloned upstream at a β-globin minimal promoter. The β-globin 5' untranslated region up to the initiation ATG is supplied to direct efficient translation of the enzyme.

Suitable promoters which may be used in vectors described above, include MLV, CMN, RSV and adenovirus promoters. Preferred adenovirus promoters are the adenovirus early gene promoters. Strong mammalian promoters may also be suitable. An example of such a promoter is the EF-lα promoter which may be obtained by reference to Mizushima and Νagata ((1990), Νucl. Acids Res. 18; 5322). Variants of such promoters retaining substantially similar transcriptional activities may also be used. - Nitroreductase

Compounds of the formula (I) or (II) can be activated by reduction of one (or more) of the available nitro groups by nitroreductase.

Preferably, the enzyme is a non-mammalian nitroreductase enzyme, such as a bacterial nitroreductase. An E.coli nitroreductase as disclosed in WO93/08288 is particularly preferred. The enzyme may be modified by standard recombinant DNA techniques, e.g. by cloning the enzyme, determining its gene sequence and altering the gene sequence by methods such as truncation, substitution, deletion or insertion of sequences for example by site-directed mutagenesis. Reference may be made to "Molecular Cloning" by Sambrook et al. (1989, Cold Spring Harbor) for discussion of standard recombinant DNA techniques. The modification made may be any which still leaves the enzyme with the ability to reduce the nitro group in formula I or II but alters other properties of the enzyme, for example its rate of reaction or selectivity. In addition, small truncations in the N- and/or C-terminal sequence may occur as a result of the manipulations required to produce a vector in which a nucleic acid sequence encoding the enzyme is linked to the various other vector sequences. ADEPT For applications in ADEPT systems, an antibody directed against a tumour specific marker is linked to the nitroreductase enzyme, which may be modified as described above. The antibody may be monoclonal or polyclonal. For the purposes of the present invention, the term "antibody", unless specified to the contrary, includes fragments of whole antibodies which retain their binding activity for a tumour target antigen. Such fragments include Fv, F(ab') and F(ab')₂ fragments, as well as single chain antibodies. Furthermore, the antibodies and fragments thereof may be humanised antibodies, e.g. as described in EP-A-239400.

The antibodies may be produced by conventional hybridoma techniques or, in the case of modified antibodies or fragments, by recombinant DNA technology, eg by the expression in a suitable host vector of a DNA construct encoding the modified antibody or fragment operably linked to a promoter. Suitable host cells include bacterial (eg. E.coli), yeast, insect and mammalian. When the antibody is produced by such recombinant techniques the enzyme may be produced by linking a nucleic acid sequence encoding the enzyme (optionally modified as described above) to the 3 ' or 5' end of the sequence of the construct encoding the antibody or fragment thereof. Applications of the invention

Compounds of the invention can be used in vitro or in vivo for a range of applications. For example, a number of vector systems for the expression of nitroreductase in a cell have been developed. The further development of such systems (e.g. the development of promoters suitable for specific cell types) requires suitable candidate prodrugs capable of killing cells when activated by nitroreductase. Prodrug compounds of the present invention may be used in such model systems. The model systems may be in vitro model systems or xenograft model systems comprising for example human tumour cells implanted in nude mice.

Compounds of the invention which are not activatable by an enzyme may be tested in vitro against panels of different tumour cells types to determine efficacy against such tumour cells. The efficacy of compounds of the invention against a range of tumour cell types may be used as points of reference for the development of further antitumour compounds. Compounds of the present invention may also be tested in combination with additional anti- cancer compounds to determine potential combination drug systems, for example combinations which are synergistic.

The compounds of the invention may also be used in a method of treatment of the human or animal body. Such treatment includes a method of treating the growth of neoplastic cells in a patient with neoplastic disease which comprises administering to a patient in need of treatment a compound of formula (I) or (II) of the invention as part of an ADEPT or GDEPT therapy system. Neoplastic diseases include leukaemia and solid tumours such as breast, bowel and lung tumours including small cell lung carcinoma.

It will be understood that where treatment of tumours is concerned, treatment includes any measure taken by the physician to alleviate the effect of the tumour on a patient. Thus, although complete remission of the tumour is a desirable goal, effective treatment will also include any measures capable of achieving partial remission of the tumour as well as a slowing down in the rate of growth of a tumour including metastases. Such measures can be effective in prolonging and/or enhancing the quality of life and relieving the symptoms of the disease. ADEPT therapy

The antibody/enzyme conjugate for ADEPT can be administered simultaneously but it is often found preferable, in clinical practice, to administer the enzyme/agent conjugate before the prodrug, e.g. up to 72 hours or even 1 week before, in order to give the enzyme/agent conjugate an opportunity to localise in the region of the tumour target. By operating in this way, when the prodrug is administered, conversion of the prodrug to the cytotoxic agent tends to be confined to the regions where the enzyme/agent conjugate is localised, i.e. the region of the target tumour, and the premature release of the compound produced by the action of the nitroreductase on the compound of formula (I) or (II) is minimised.

In ADEPT the degree of localisation of the enzyme/agent conjugate (in terms of the ratio of localized to freely circulating active conjugate) can be further enhanced using the clearance and/or inactivation systems described in WO89/10140. This involves, usually following administration of the conjugate and before administration of the prodrug, the administration of a component (a "second component") which is able to bind to part of the conjugate so as to inactivate the enzyme and/or accelerate the clearance of the conjugate from the blood. Such a component may include an antibody to the enzyme component of the system which is capable of inactivating the enzyme.

The second component may be linked to a macromolecule such as dextran, a liposome, albumin, macroglobulin or a blood group O erythrocyte so that the second component is restrained from leaving the vascular compartment. In addition or as an alternative, the second component may include a sufficient number of covalently bound galactose residues, or residues of other sugars such as lactose or mannose, so that it can bind the conjugate in plasma but be removed together with the conjugate from plasma by receptors for galactose or other sugars in the liver. The second component should be administered and designed for use such that it will not, to any appreciable extent, enter the extravascular space of the tumour where it could inactivate localised conjugate prior to and during administration of the prodrug.

In ADEPT systems, the dose of the prodrug and conjugate will ultimately be at the discretion of the physician, who will take into account such factors as the age, weight and condition of the patient. Suitable doses of prodrug and conjugate are given in Bagshawe et al. Antibody, Immunoconjugates, and Radiopharmaceuticals (1991), 4, 915-922. A suitable dose of conjugate may be from 500 to 200,000 enzyme units/m² (e.g. 20,000 enzyme units/m²) and a suitable dose of prodrug may be from about 0.1 to 200 mg/Kg, preferably about from 10 to 100 mg/Kg per patient per day.

In order to secure maximum concentration of the conjugate at the site of desired treatment, it is normally desirable to space apart administration of the two components by at least 4 hours. The exact regime will be influenced by various factors including the nature of the tumour to be targeted and the nature of the prodrug, but usually there will be an adequate concentration of the conjugate at the site of desired treatment within 48 hours.

The ADEPT system when used with nitroreductase also preferably comprises a suitable cofactor for the enzyme. Suitable cofactors include a riboside or ribotide of nicotinic acid or nicotinamide.

The antibody/enzyme conjugate may be administered by any suitable route usually used in ADEPT therapy. This includes parenteral administration of the antibody in a manner and in formulations similar to that described below. GDEPT therapy

For use of the vectors in therapy, the vectors will usually be packaged into viral particles and the particles delivered to the site of the tumour, as described in for example Ram et al. (ibid). The viral particles may be modified to include an antibody, fragment thereof (including a single chain) or tumour-directed ligand to enhance targeting of the tumour. Alternatively the vectors may be packaged into liposomes. The liposomes may be targeted to a particular tumour. This can be achieved by attaching a tumour-directed antibody to the liposome. Viral particles may also be incorporated into liposomes. The particles may be delivered to the tumour by any suitable means at the disposal of the physician. Preferably, the viral particles will be capable of selectively infecting the tumour cells. By "selectively infecting" it is meant that the viral particles will primarily infect tumour cells and that the proportion of non-tumour cells infected is such that the damage to non-tumour cells by administration of a prodrug will be acceptably low, given the nature of the disease being treated. Ultimately, this will be determined by the physician.

One suitable route of administration is by injection of the particles in a sterile solution. Viruses, for example isolated from packaging cell lines may also be administered by regional perfusion or direct intratumoral direction, or direct injection into a body cavity (intracaviterial administration), for example by intra-peritoneum injection.

The exact dosage regime for GDEPT will, of course, need to be determined by individual clinicians for individual patients and this, in turn, will be controlled by the exact nature of the prodrug and the cytotoxic agent to be released from the prodrug but some general guidance can be given. Chemotherapy of this type will normally involve parenteral administration of modified virus and administration by the intravenous route is frequently found to be the most practical.

In GDEPT systems the amount of virus or other vector delivered will be such as to provide a similar cellular concentration of enzyme as in the ADEPT system mentioned above. Typically, the vector will be administered to the patient and then the uptake of the vector by transfected or infected (in the case of viral vectors) cells monitored, for example by recovery and analysis of a biopsy sample of targeted tissue. This may be determined by clinical trials which involve administering a range of trial doses to a patient and measuring the degree of infection or transfection of a target cell or tumour. The amount of prodrug required will be similar to or greater than that for ADEPT systems.

In using a GDEPT system the prodrug will usually be administered following administration of the vector encoding an enzyme. Suitable doses of prodrug are from about 0.1 to 200 mg/Kg, preferably about from 10 to 100 mg/Kg per patient per day. Administration of prodrug

While it is possible for a compound of formula (I) or (II) to be administered alone it is preferable to present it as a pharmaceutical formulation. Suitable formulations comprise the compounds, together with one or more acceptable carriers thereof and optionally other therapeutic ingredients. The carrier or carriers must be "acceptable" in the sense of being compatible with the other ingredients of the formulation and not deleterious to the recipients thereof, for example, liposomes. Suitable liposomes include, for example, those comprising the positively charged lipid (N[ 1 -(2,3-dioleyloxy)propyl]-N,N,N-triethylammonium (DOTMA), those comprising dioleoylphosphatidylethanolamine (DOPE), and those comprising 3 β[N-(N',N'-dimethylaminoethane)-carbamoyl]cholesterol (DC-Choi).

Formulations suitable for parenteral or intramuscular administration include aqueous and non-aqueous sterile injection solutions which may contain anti-oxidants, buffers, bacteriostats, bactericidal antibiotics and solutes which render the formulation isotonic with the blood of the intended recipient; and aqueous and non-aqueous sterile suspensions which may include suspending agents and thickening agents, and liposomes or other microparticulate systems which are designed to target the compound to blood components or one or more organs. The formulations may be presented in unit-dose or multi-dose containers, for example sealed ampoules and vials, and may be stored in a freeze-dried (lyophilized) condition requiring only the addition of the sterile liquid carrier, for example water, for injections, immediately prior to use. Injection solutions and suspensions may be prepared extemporaneously from sterile powders, granules and tablets of the kind previously described. It should be understood that in addition to the ingredients particularly mentioned above the formulations may include other agents conventional in the art having regard to the type of formulation in question. Of the possible formulations, sterile pyrogen-free aqueous and non- aqueous solutions are preferred.

The doses may be administered sequentially, eg. at daily, weekly or monthly intervals, or in response to a specific need of a patient. Preferred routes of administration are oral delivery and injection, typically parenteral or intramuscular injection or intratumoral injection. The exact dosage regime will, of course, need to be determined by individual clinicians for individual patients and this, in turn, will be controlled by the exact nature of the compound of formula (I) or (II) but some general guidance can be given. Typical dosage ranges generally will be those described above which may be administered in single or multiple doses. Other doses may be used according to the condition of the patient and other factors at the discretion of the physician. The following Examples illustrate the invention. General procedures

Analyses were carried out in the Microchemical Laboratory, University of Otago, Dunedin, NZ. Melting points were determined on an Electrothermal 2300 Melting Point Apparatus. IR spectra were recorded on a Midac FT-IR as KBr discs, unless otherwise stated. NMR spectra were obtained on a Bruker AM-400 spectrometer at 400 MHz for 'H and 100 MHz for ¹ C spectra. Spectra were obtained in CDC1₃ unless otherwise specified, and are referenced to Me₄Si. Chemical shifts and coupling constants were recorded in units of ppm and Hz, respectively. Assignments were determined by APT, COSY, HSQC, and HMBC experiments. Mass spectra were determined on a VG-70SE mass spectrometer using an ionizing potential of 70 eV at a nominal resolution of 1000. High resolution spectra were obtained at nominal resolutions of 3000, 5000, or 10000 as appropriate. All spectra were obtained as electron impact (El) using PFK as the reference unless otherwise stated. Solutions in organic solvents were dried with anhydrous Na-SO₄. Solvents were evaporated under reduced pressure on a Buchi rotary evaporator. Thin-layer chromatography was carried out on aluminium-backed silica gel plates (Merck 60 F₂₅₄) with visualisation of components by UV light (254 ran) or exposure to I₂. Column chromatography was carried out on silica gel, (Merck 230-400 mesh). All compounds designated for biological testing were analyzed at >99% purity by reverse phase HPLC using a Philips PU4100 liquid chromatograph, a

Phenomenex BondClone 10-C18 stainless steel column (300mm x 3.9 mm i.d.)and a Philips PU4120 diode array detector. Chromatograms were run using various gradients of aqueous (1 M NaH₂PO₄, 0.75 M heptanesulfonic acid, 0.5 M dibutylammonium phosphate, and MilliQ water in a 1 : 1 : 1 :97 ratio) and organic (80% MeOH/MilliQ water) phases. DCM refers to dichloromethane; DIEA refers to diisopropylethylamine, DMF refers to dry dimethyl formamide; DMSO refers to dimethylsulphoxide; ether refers to diethyl ether; EtOAc refers to ethyl acetate; EtOH refers to ethanol; iPr₂O refers to diisopropyl ether; light petroleum refers to petroleum ether, boiling range 40-60 °C; MeOH refers to methanol; THF refers to tetrahydrofuran dried over sodium benzophenone ketyl. All solvents were freshly distilled.

Example 1. Preparation of 4-nitrobenzyl 4-(l,3-benzothiazol-2-yl)phenylcarbamate (8). 4-Nitrophenyl chloroformate (0.15 g, 0.46 mmol) was added to a stirred solution of 2- (4-aminophenyl)benzthiazole (7) [D-F. Shi, T.D. Bradshaw, S. Wrigley, C J. McCall, P. Lelieveld, I. Fitchner, M.F.G.Stevens. J. Med. Chem., 1996, 39, 3375] in pyridine (5 mL) and the solution stirred at 20 °C for 2 h. The solution was dilute with water (10 mL) and the mixture stirred for 40 min, filtered and the solid triturated with hot EtOH to give 8 (157 mg, 87%) as a pale green powder, mp 232-234 °C; Η NMR [(CD₃)₂SO]δ 10.31 (s, 1 H, OCONH), 8.29 (ddd, J= 8.7, 3.2, 2.2 Hz, 2 H, H 3", H 5"), 8.11 (d, J= 8.3 Hz, 1 H, H 4), 8.04 (br d, J= 8.7 Hz, 2 H, H 2", H 6"), 8.02 (d, J= 8.3 Hz, 1 H, H 7), 7.72 (br d, J= 8.7 Hz, 2 H, H 2', H 6'), 7.68 (br d, J= Hz, 2 H, H 3', H 5'), 7.51-7.55 (m, 1 H, H 5), 7.40-7.46 (m, 1 H, H 6), 5.32 (s, 2 H, CH₂O); Anal. (C₂₁H₁₅N₃O₄S) C, H, N.

Example 2A. Preparation of 2-methoxy-4-nitrobenzyl 4-[bis(2- chloroethyI)amino]phenylcarbamate (32).

Methyl 2-methoxy-4-nitrobenzoate (28). An ethereal solution of diazomethane (CAUTION) was added to a solution of 4-nitrosalicylic acid (27) (1.0 g, 5.46 mmol) in ether (50 mL) until a yellow colour persisted and the solution stood at 20 °C for 4 h. The reaction was quenched with glacial acetic acid (2 mL), poured into sat. aq. NaHCO₃ solution and extracted with ether (2 x 50 mL). The combined organic fractions were dried and the solvent evaporated to give 28 (1.11 g, 96%) as white needles, mp (ether) 89-90 °C; IR N 1740, 1526, 1252, and 1086 cm^"1; 'H NMR δ 7.89 (d, J= 8.3 Hz 1 H, H 5), 7.82-7.85 (m, 2 H, H 3, H 6), 4.01 (s, 3 H, OCH₃), and 3.94 (s, 3 H, OCH₃); ^!3C NMR 165.2 (CO₂), 159.2 (C 2), 150.7 (C 4), 132.0 (C 1), 126.0 (C 6), 115.0 (C 5), 106.9 (C 3), 56.6 (OCH₃), and 52.6 (OCH₃); Anal. (C₉H₉NO₅) C, H, N.

2-Methoxy-4-nitrobenzyl alcohol (29). A solution of 28 (0.9 g, 4.26 mmol) in THF (20 mL) was added dropwise to a stirred solution of DIBALH (1 M solution in toluene, 13.4 mL, 13.4 mmol) in THF (20 mL) at 2 °C and the solution stirred at 2 °C for 15 min. The solvent was evaporated and residue partitioned between EtOAc (100 mL) and water (100 mL). The aqueous fraction was extracted with EtOAc (2 x 50 mL) and the combined organic fraction dried and the solvent evaporated. The residue was purified by chromatography, eluting with 50% EtOAc/light petroleum, to give 29 (0.74 g, 93%) as cream needles, mp (EtOAc/light petroleum) 103-104 °C; IR n 3310, 1523, 1250, and 1036 cm^"1; 'H NMR δ 7.86 (dd, J= 8.3, 2.1 Hz, 1 H, H 5), 7.71 (d, J= 2.1 Hz, 1 H, H 3), 7.52 (d, J= 8.3 Hz, 1 H, H 6), 4.76 (d, J= 5.5 Hz, 2 H, CH₂O), 3.96 (s, 3 H, OCH₃), and 2.27 (br s, 1 H, OH); ¹³C NMR δ 157.1, 148.3, 136.6, 127.9, 1 16.0, 105.0, 60.7, and 55.9; Anal. (C₈H₉NO₄) C, H, N.

2-Methoxy-4-nitrobenzyl 4-[bis(2-hydroxyethyl)amino]phenylcarbamate (31). Pyridine (91 μh, 1.13 mmol) was added dropwise to a stirred solution of 29 (207 mg, 1.13 mmol) and triphosgene (117 mg, 0.40 mmol) in THF (10 mL) at 5 °C and the suspension stirred at 5 °C for 1 h. A solution of N',N'-bis(2 -hydro xyethyl)-l,4-benzenediamine (57) [prepared by catalytic hydrogenation of NN-bis-(2-hydroxyethyl) 4-nitroaniline (30)] (244 mg, 1.24 mmol) with Pd/C under H₂ (60 psi) in EtOH) in THF ( 10 mL) and DMF ( 10 mL) was added and the mixture stirred at 20 °C for 16 h. The solvent was evaporated and the residue purified by chromatography, eluting with EtOAc to give 31 (251 mg, 55%) as orange prisms, mp (EtOAc) 153-154 °C; 'H ΝMR δ 9.45 (br s, 1 H, OCOΝH), 7.90 (dd, J= 8.3, 2.0 Hz, 1 H, H 5'), 7.80 (d, J= 2.0 Hz, 1 H, H 3'), 7.60 (br d, J- 8.3 Hz, 1 H, H 6'), 7.21 (br d, J= 9.0 Hz, 2 H, H 2, H 6), 6.61 (d, J= 9.0 Hz, 2 H, H 3, H 5), 5.17 (s, 2 H, CH₂O), 4.71 (t, J= 5.4 Hz, 2 H, 2 OH), 3.97 (s, 3 H, OCH₃), 3.48-3.53 (m, 4 H, 2 CH₂O), 3.32- 3.37 (m, 4 H, 2 CH₂Ν); ¹³C NMR δ 157.4, 153.7, 148.6, 144.6, 133.2, 129.0, 127.8, 120.7 (2), 116.0, 111.9 (2), 105.9, 60.6, 58.7 (2), 56.7, 53.9 (2); Anal. (C_I9H₂₃N₃O₇) C, H, N.

2-Methoxy-4-nitrobenzyl 4-[bis(2-chloroethyl)amino]phenylcarbamate (32).

Methanesulphonyl chloride (129 μJL, 1.67 mmol) was added dropwise to a stirred solution of 31 (226 mg, 0.55 mmol) in pyridine (10 mL) at 20 °C and the solution stirred for 1 h. The solvent was evaporated and the residue partitioned between DCM/water (100 mL). The aqueous fraction was extracted with DCM (2 50 mL) and the combined organic fraction washed with brine (50 mL), dried and the solvent evaporated. The residue was dissolved in DMF (10 mL), LiCl (0.15 g, 3.34 mmol) added, and the mixture stirred at 80 °C for 2 h. The solvent was evaporated and the residue partitioned between EtO Ac/water (100 mL). The aqueous fraction was extracted with EtOAc (2 x 25 mL). The combined organic fraction was washed with brine (30 mL), dried, and the solvent evaporated. The residue was purified by chromatography, eluting with 25% EtOAc/light petroleum, to give 32 (230 mg, 93%) as pale green needles, mp (EtOAc/light petroleum) 129-130 °C; Η NMR δ 7.84 (dd, J= 8.3, 2.1 Hz, 1 H, H 5'), 7.72 (d, J= 2.1 Hz, 1 H, H 3'), 7.51 (d, J= 8.3 Hz, 1 H, H 6'), 7.27 (br d, J= 9.0 Hz, 2 H, H 2, H 6), 6.65 (ddd, J= 9.0, 3.5, 2.1 Hz, 2 H, H 3, H 5), 5.29, (s, 2 H, CH₂O), 3.96 (s, 3 H, OCH₃), 3.68-3.72 (m, 4 H, 2 CH₂N), 3.58-3.63 (m, 4 H, 2 x CH₂C1); ¹³C NMR δ 157.2, 153.4, 148.6, 142.9, 132.2, 128.5, 128.1, 121.4 (2), 115.7, 112.7 (2), 105.3, 61.3, 56.0, 53.7 (2), 40.5 (2); Anal. (C₁₉H₂₁Cl₂N₃O₅) C, H, N.

Example 2B. Preparation of 2-methoxy-4-nitrobenzyl 3-(chloromethyl)-l-[(5,6,7- trimethoxy-lH-indol-2-yl)carbonyl]-2,3-dihydro-lH-indol-6-ylcarbamate (34).

Pyridine (20 μh, 0.25 mmol) was added dropwise to a stirred solution of 2-methoxy-4- nitrobenzyl alcohol (29) (45 mg, 0.25 mmol) and triphosgene (26 mg, 0.09 mmol) in THF (10 mL) at 5 °C and the suspension stirred at 5 °C for 1 h. A solution of 6-amino-3-

(chloromethyl)-l-[(5,6,7-trimethoxyindol-2-yl)carbonyl]indoline (33) [M. Tercel and W. A. Denny. J. Chem. Soc. Perkin Trans. 1, 1998, 509] (102 mg, 0.25 mmol) in THF (10 mL) was added and the mixture stirred at 20 °C for 16 h. The suspension was filtered and the solvent evaporated. The residue was purified by chromatography, eluting with 40%EtOAc/DCM, to give 34 (102 mg, 65%) as a tan powder, mp (DCM/pet. ether) 144- 150 °C; 'H NMR δ 9.74 (s, 1 H, indole-NH), 8.26 (d, J= 0.8 Hz, 1 H, H 7), 7.62-7.68 (m, 3 H, H 5, H 3", H 5"), 7.58 (br s, 1 H, OCONH), 7.35 (br d, J= 8.1 Hz, 1 H, H 6"), 7.20 (d, J = 8.3 Hz, 1 H, H 4), 6.91 (d, J= 2.1 Hz, 1 H, H 3'), 6.83 (s, 1 H, H 4'), 5.21 (s, 2 H, CH₂O), 4.58 (dd, J= 10.6, 8.9 Hz, 1 H, H 2), 4.41 (d, J= 10.6, 4.3 Hz, 1 H, H 2), 4.03, (s, 3 H, OCH₃), 3.92 (s, 3 H, OCH₃), 3.90 (s, 3 H, OCH₃), 3.89 (s, 3 H, OCH₃), 3.76-3.80 (m, 2 H, H 3, CH₂C1), 3.51 (dd, J= 11.7, 10.6 Hz, 1 H, CH₂C1); ¹³C NMR δ 160.5, 157.1, 153.1, 150.2, 148.4, 144.0, 140.5, 138.8, 138.7, 132.0, 129.5, 128.3, 126.0, 125.6, 124.5, 123.5, 115.6, 115.5, 108.8, 106.7, 105.5, 97.5, 61.4, 61.3, 61.1, 56.2, 55.9, 54.8, 46.9, 43.2; MS (FAB⁺) m/z 627 (MH⁺, 4%), 625 (MH⁺, 12), 234 (25), 149 (100); HRMS (FAB⁺) calc. for C₃₀H₃₀ ³⁵C1N₄O₁₀ (MH⁺) m/z 625.1701, found 625.1690; C₃₀H₃₀ ³⁷C1N₄O₁₀ (MH⁺) m/z 627.1672, found 627.1623; Anal. (C₃₀H₂₉C1N₄O₉) C, H, N.

Example 2C. Preparation of 2-methoxy-4-nitrobenzyl l-(chloromethyl)-3-[(5,6,7- trimethoxy-lH-indol-2-yl)carbonyI]-2,3-dihydro-lH-benzo[e]indol-5-ylcarbamate (35). Phosgene (300 μL, 0.3 mmol, 1M in toluene) was added to a stirred solution of 2- methoxy-4-nitrobenzyl alcohol (29) (20 mg, 0.11 mmol) in THF (10 mL) and stiπed at 20 °C for 16 h. The solvent was evaporated, the residue dissolved in THF (10 mL), a solution of amine 1 [G. J. Atwell, W. R. Wilson, W. A. Denny, Bioorg. Med. Chem. Lett., 1997, 7, 1483] (50 mg, 0.11 mmol) in THF ( 10 mL) was added and the solution stirred at 20 °C for 4 days. The solvent was evaporated and the residue purified by chromatography, eluting with 50% EtOAc/light petroleum to give 35 (31 mg, 43%) as a tan solid, mp (EtOAc/light petroleum) 162-165 °C; Η NMR δ 9.52 (s, 1 H, indole-NH), 8.90 (s, 1 H, OCONH), 7.90 (d, J= 8.7 Hz, 1 H, H 6), 7.80 (d, J- 8.7 Hz, 1 H, H 5"), 7.77 (d, J= 8.4 Hz, 1 H, H 9), 7.70 (br s, 1 H, H 3"), 7.50-7.57 (m, 2 H, H 8, H 6"), 7.42-7.47 (m, 1 H, H 7), 7.25 (br s, 1 H, H 4), 6.99 (d, J= 2.2 Hz, 1 H, H 3'), 6.87 (s, 1 H, H 4'), 5.34 (d, J= 1.9 Hz, 2 H, CH₂O), 4.78 (dd, J= 10.7, 1.6 Hz, 1 H, H 2), 4.64 (dd, J= 10.7, 8.8 Hz, 1 H, H 2), 4.07- 4.17 (m, 5 H, H 1, CH₂C1, OCH₃), 3.95 (s, 3 H, OCH₃), 3.94 (s, 3H, OCH₃), 3.91 (s, 3 H, OCH₃), 3.45 (t, J= 10.9 Hz, 1 H, CH₂C1); ¹³C NMR δ 160.3, 157.2, 154.0, 150.2, 148.6, 141.6, 140.6, 138.9, 133.9, 132.0, 129.7, 129.6, 128.8, 127.4, 127.2, 125.6, 125.4, 125.0, 123.6, 123.1, 123.0, 121.8, 122.4, 115.7, 106.5, 105.1, 97.6, 61.8, 61.5, 61.1, 56.2, 56.0, 54.9, 45.8, 43.4; MS (FAB⁺) m/z 675 (MH⁺, 10%), 677 (4), 659 (1), 639 (1), 517 (5), 234 (25); HRMS (FAB⁺) calc. for C₃₅H₃₂ ³⁵ClN₄O₉ (MH⁺) m/z 675.1858, found 674.1832; calc for C₃₅H₃₂ ³⁷ClN₄O₉ (MH⁺) m/z 677.1828, found 677.1834; Anal. (C₃₄H₃₁ClN₄O₉.H₂O) C, H, N.

Example 2D. Preparation of 2-methoxy-4-nitrobenzyl 4-(l,3-benzothiazol-2- yl)phenylcarbamate (36). Pyridine (36 mL, 0.44 mmol) was added dropwise to a stirred solution of alcohol of 2-methoxy-4-nitrobenzyl alcohol (29) (81 mg, 0.44 mmol) and triphosgene (66 mg, 0.22 mg) in DCM (10 mL) and the mixture was stirred at 20°C for 20 min. A solution of 2-(4-aminophenyl)benzthiazole (7) [D-F. Shi, T. D. Bradshaw, S. Wrigley, C. J. McCall, P. Lelieveld, I. Fitchner, M. F. G. Stevens. J. Med. Chem., 1996, 39, 3375] (100 mg, 0.44 mmol) in DCM (5 mL) and the mixture stirred at 20 °C for 4 h. The mixture was partitioned between EtOAc (100 mL) and sat. aq. KHCO₃ solution (50 mL), the organic fraction dried and the solvent evaporated. The residue was slurried in warm EtOAc/MeOH (1 : 1, 20 mL), filtered and the solvent evaporated to give 36 (123 mg, 64%) as a pale green powder mp (EtOH) 213-214 °C; Η NMR [(CD₃)₂SO] δ 10.31 (s, 1 H, OCONH), 8.11 (d, J= 7.8 Hz, 1 H, H 4), 8.01-8.06 (m, 3 H, H 7, H 2', H 6'), 7.92 (dd, J = 8.3, 2.2 Hz, 1 H, H 5"), 7.81 (d, J= 2.2 Hz, 1 H, H 3"), 7.65-7.69 (m, 3 H, H 3', H 5' H 6"), 7.51-7.55 (m, 1 H, H 5), 7.40-7.46 (m, 1 H, H 6), 5.27 (s, 2 H, CH₂O) 3.98 (s, 3 H, OCH₃);¹ C NMR [(CD₃)₂SO] δ 166.9, 157.1, 153.6, 152.9, 148.3, 141.8, 134.2, 132.0, 129.0 (2), 128.1, 127.0, 126.5, 125.1, 122.4, 122.1, 118.3 (2), 115.5, 105.5, 60.7, 56.2; Anal. (C₂₂H₁₇N₃O₅S) C, H, N.

Example 2E. Preparation of 2-methoxy-4-nitrobenzyl doxorubicin carbamate (38). 2-Methoxy-4-nitrobenzyl 4-nitrophenyl carbonate (37). A solution of 4-nitrophenyl chloroformate (1.00 g, 4.97 mmol) in pyridine (4 mL) was added dropwise to a stirred solution of 2-methoxy-4-nitrobenzyl alcohol (29) (617 mg, 3.31 mmol) in pyridine (15 mL) at 20 °C and the solution stirred for 16 h. The solvent was evaporated and the residue purified by chromatography, eluting with a gradient (20-50%) EtOAc/light petroleum, to give 37 (928 mg, 80%) as pale yellow solid, mp (EtOAc/light petroleum) 105-106 °C; 'H NMR δ 8.28 (ddd, J- 9.2, 3.1, 2.1 Hz, 2 H, H 3'), 7.89 (dd, J- 8.3, 2.1 Hz, 1 H, H 5), 7.77 (d, J= 2.1 Hz, 1 H, H 3), 7.58 (d, J= 8.3 Hz, 1 H, H 6), 7.40 (ddd, J= 8.3, 3.1, 2.1 Hz, 2 H, H 2'), 5.41 (s, 2 H, CH₂O), 4.00 (s, 3 H, OCH₃); ¹³C NMR δ 157.6 (C 2), 155.4 (OCO₂), 152.3 (C 1), 149.2 (C 4), 145.5 (C 4'), 129.8 (C 1), 129.3 (C 6), 125.3 (C 2'), 121.7 (C 3'), 115.8 (C 5), 105.5 (C 3), 65.3 (CH₂O), 56.2 (OCH₃); Anal. (C₁₅H₁₂N₂O₈) C, H, N.

2-Methoxy-4-nitrobenzyl doxorubicin carbamate (38). A solution of carbonate 37 (23 mg, 66 mmol) in DMF (2 mL) was added to a solution of doxorubicin (13) (30 mg, 55 mmol) and Et₃N (9 mL 66 mmol) in DMF (5 mL) at 20 °C and the solution stirred for 16 h. The solvent was evaporated and the residue purified by chromatography, eluting with a gradient (0-5%) of MeOH/DCM, to give 38 (37 mg, 88%) as a red solid, mp (DCM) 159- 161 °C; Η NMR δ 13.97 (s, 1 H, 6-OH), 13.22 (s, 1 H, 11-OH), 8.02 (dd, J= 8.0, 1.0 Hz, 1 H, H 1), 7.77-7.81 (m, 2 H, H 2, H 5"), 7.66 (br s, 1 H, H 3"), 7.41 (d, J= 8.0 Hz, 1 H, H 6"), 7.39 (dd, J= 8.0, 1.0 Hz, 1 H, H 3), 5.52 (br d, J= 3.3 Hz, 1 H, H 1'), 5.29 (br s, 1 H, H 7), 5.25 (d, J= 8.7 Hz, 1 H, OCONH), 5.13 (2 d, J= 14.0 Hz, 2 H, CH₂O), 4.75 ( s, 2 H, H 14), 4.51 (s, 1 H, 9-OH), 4.13-4.17 (m, 1 H, H 5'), 4.08 (s, 3 H, 4-OCH₃), 3.90 (s, 3 H, 2"-OCH₃), 3.84-3.88 (m, 1 H, H 3'), 3.69 (s, 1 H, H 4'), 3.24 (dd, J= 18.9, 1.3 Hz, 1 H, H 10), 3.03 (s, 1 H, 14-OH), 3.01 (d, J= 18.9 Hz, 1 H, H 10), 2.34 (br d, J= 14.7 Hz, 1 H, H 8), 2.18 (dd, J= 14.7, 4.0 Hz, 1 H, H 8), 2.02 (br s, 1 H, 4'-OH), 1.90 (dd, J= 13.2, 4.7 Hz, 1 H, H 2'), 1.79 (dd, J= 13.2, 3.3 Hz, 1 H, H 2'), 1.30 (d, J= 6.5 Hz, 3 H, H 6'); ¹³C NMR δ 213.7 (C 13), 187.1 (C 5), 186.7 (C 12), 161.0 (C 4), 157.0 (C 2"), 156.1 (C 6), 155.6 (C 11), 155.2 (OCONH), 148.5 (C 4"), 135.8 (C 2), 135.5 (C12a), 133.5 (C 6a), 133.4 (C 10a), 132.5 (C 1"), 128.4 (C 6"), 120.8 (C 4a), 1 19.9 (C 1), 118.5 (C 3), 115.7 (C 5"), 111.6 (C 5a), 111.4 (C 1 la), 105.1 (C 3"), 100.7 (C 1 '), 76.6 (C 9), 69.8 (C 7), 69.6 (C 4'), 67.2 (C 5'), 65.5 (C 14), 61.1 (CH₂O), 56.7 (4-OCH₃), 56.0 (2'-OCH₃), 47.1 (C 3'), 35.6 (C 8), 34.0 (C 10), 30.2 (C 2), 16.8 (C 6'); MS (FAB⁺) m/z 753 (MH⁺, 0.3%); HRMS (FAB⁺) calc. for C₃₆H₃₇N₂O₁₆ (MH⁺) m/z 753.2143, found 753.2100; Anal (C₃₆H₃₆N₂O₁₆) C, H, N.

Example 2F. Preparation of 4-({[(2-methoxy-4- nitrobenzyl)oxy]carbonyl}amino)benzyl doxorubicin carbamate (42).

2-Methoxy-4-nitrobenzyl 4-({[tert-butyl(dimethyl)silyl]oxy}methyl)phenylcarbamate (39). Et₃N (0.40 mL, 2.84 mmol) was added to a stirred suspension of carbonate 37 (0.90 g, 2.58 mmol), 4-({[tert-butyl(dimethyl)silyl]oxy}methyl)aniline (9) (0.64 g, 2.71 mmol), HOBT (0.35 g, 2.58 mmol), and 4 A molecular sieves (900 mg) in THF (80 mL) and the mixture stirred at 20 °C for 16 h. The solvent was evaporated and the residue partitioned between EtOAc (100 mL) and water (100 mL). The organic fraction was washed with 1 M HCI (2 x 40 mL), water (100 mL), brine (50 mL), dried, and the solvent evaporated. The residue was purified by chromatography, eluting with 20% EtOAc/light petroleum, to give 39 (0.89 g, 77%) as a white solid, mp (EtOAc/light petroleum) 120-122 °C; 'H NMR δ 7.84 (dd, J= 8.3, 2.1 Hz, 1 H, H 5'), 7.72 (d, J= 2.1 Hz, 1 H, H 3'), 7.51 (d, J= 8.3 Hz, 1 H, H 6'), 7.35 (d, J= 8.3 Hz, 2 H, H 2, H 6), 7.26 (d, J- 8.3 Hz, 2 H, H 3, H 5), 6.76 (br s, 1 H, OCONH), 5.30 (s, 2 H, CH₂O), 4.69 (s, 2 H, CH₂OSi), 3.93 (s, 3 H, OCH₃), 0.92 (s, 9 H, SiC(CH₃)₃), 0.09 (s, 6 H, Si(CH₃)₂); ¹³C NMR δ 157.3 (C 2'), 153.0 (OCONH), 148.7 (C 4'), 137.0 (C 4), 136.4 (C 1), 132.1 (C 1 '), 128.7 (C 6'), 126.9 (C 3, C 5), 118.6 (C 2, C 6), 115.7 (C 5'), 105.2 (C 3'), 64.6 (CH₂O), 61.4 (CH₂O), 56.0 (OCH₃), 26.9 (SiC(CH₃)₃), 18.4 (SiC(CH₃)₃), -5.2 (Si(CH₃)₂); Anal. (C₂₂H₃₀N₂O₆Si) C, H, N.

2-Methoxy-4-nitrobenzyl 4-(hydroxymethyl)phenylcarbamate (40). 1 M HCI (4 mL, 4 mmol) was added to a stirred solution of silyl ether 39 (0.89 g, 0.2 mmol) in MeOH (10 mL) and stirred at 20 °C for 1 h. The solution was poured into brine (50 mL) and extracted with EtOAc (3 50 mL). The combined organic fraction was washed with water (50 mL), dried, and the solvent evaporated. The residue was purified by chromatography, eluting with a gradient (20-50%) EtOAc/light petroleum, to give 40 (628 mg, 95%) as a white solid, mp (EtOAc/light petroleum) 164-165 °C; Η NMR [(CD₃)₂SO] δ 9.83 (br s, 1 H, OCONH), 7.90 (dd, J= 8.3, 2.1 Hz, 1 H, H 5'), 7.80 (d, J= 2.1 Hz, 1 H, H 3'), 7.63 (d, J = 8.3 Hz, 1 H, H 6'), 7.41 (d, J= 8.4 Hz, 2 H, H 2, H 6), 7.22 (d, J= 8.4 Hz, 2 H, H 3, H 5), 5.21 (s, 2 H, CH₂O), 5.07 (t, J= 5.6 Hz, 1 H, OH), 4.41 (t, J= 5.6 Hz, 2 H, CH₂O), 3.97 (s, 3 H, OCH₃); ¹³C NMR [(CD₃)₂SO] δ 157.0 (C 2'), 153.0 (OCONH), 148.2 (C 4'), 137.4 (C 4), 136.7 (C 1), 132.3 (C 1'), 128.8 (C 6'), 127.0 (C 3, C 5), 117.9 (C 2, C 6), 115.5 (C 5'),

105.4 (C 3'), 62.5 (CH₂O), 60.4 (CH₂O), 56.0 (OCH₃); Anal. (C₁₆H₁₆N₂O₆) C, H, N.

4-({[(2-Methoxy-4-nitrobenzyl)oxy]carbonyl}amino)benzyl 4-nitrophenyl carbonate (41). A solution of 4-nitrophenylchloroformate (205 mg, 1.02 mmol) in THF (5 mL) was added dropwise to a stirred solution of alcohol 40 (282 mg, 0.85 mmol) and Et-N (142 μL,

1.02 mmol) in THF/DMF (1:1, 30 mL) the solution stirred at 20 °C for 16 h. The solvent was evaporated and the residue was purified by chromatography, eluting with 10% EtOAc/DCM, to give 41 (238 mg, 56 %) as a white powder mp (EtOAc/DCM) 144-146 °C; 'H NMR [(CD₃)₂SO] δ 10.01 (s, 1 H, OCONH), 8.31 (ddd, J= 9.1, 3.4, 2.2 Hz, 2 H, H 3, H 5), 7.91 (dd, J= 8.3, 2.2 Hz, 1 H, H 5"), 7.81 (d, J= 2.2 Hz, 1 H, H 3"), 7.64 (d, J=

8.3 Hz, 1 H, H 6"), 7.56 (ddd, J = 9.1, 3.4, 2.2 Hz, 2 H, H 2, H 6), 7.53 (br d, J= 8.6 Hz, 2 H, H 3', H 5'), 7.41 (br d, J= 8.6 Hz, 2 H, H 2', H 6'), 5.24 (s, 4 H, 2 x CH₂O), 3.98 (s, 3 H, OCH₃); ¹³C NMR [(CD₃)₂SO] δ 157.0 (C 2"), 155.2 (OCO₂), 153.0 (OCONH), 151.9 (C 1), 148.2 (C 4"), 145.1 (C 4), 139.4 (C 1), 132.2 (C 1'), 129.6 (C 2', C 6'), 128.9 (C 6"),

128.5 (C 4'), 125.3 (C 2, C 6), 122.6 (C 3, C 5), 118.0 (C 3', C 5'), 115.5 (C 5"), 105.5 (C 3"), 70.2 (CH₂O), 60.5 (CH₂O), 56.2 (OCH₃); MS (FAB⁺) m/z 498 (MH⁺,0.5%); HRMS (FAB⁺) calc. for C₂₃H₂₀N₃O₁₀ (MH⁺) m/z 498.1149, found 498.1151. Anal. (C₂₃H₁₉N₃O₁₀) C, H, N.

4-({[(2-Methoxy-4-nitrobenzyl)oxy] carbonyl} amino)benzyl doxorubicin carbamate

(42). A solution of carbonate 41 (52 mg, 103 μmol) in DMF (2 mL) was added dropwise to a stirred solution of doxorubicin (13) (45 mg, 86 μmol) and Et₃N (15 μL, 103 μmol) in DMF (5 mL) at 20 °C and the solution stirred at 20 °C for 24 h. The solvent was evaporated and the residue purified by chromatography, eluting with a gradient (0-5%) of MeOH/DCM, to give 42 (61 mg, 80%) as a red solid, mp (DCM) 128-131 °C; Η NMR [(CD₃)₂SO] δ 14.01 (s, 1 H, 6-OH), 13.25 (s, 1 H, 1 1-OH), 9.88 (s, 1 H, OCONH), 7.87- 7.90 (m, 3 H, H 1, H 2, H 5"'), 7.79 (d, J= 2.2 Hz, 1 H, H 3'"), 7.59-7.63 (m, 2 H, H 3, H 6'"), 7.41 (d, J- 8.3 Hz, 2 H, H 3", H 5"), 7.22 (d, J= 8.3 Hz, 2 H, H 2", H 6"), 6.81 (d, J - 8.0 Hz, 1 H, OCONH), 5.44 (s, 1 H, H 7), 5.21 (d, J= 3.0 Hz, 1 H, H 1 '), 5.19 (s, 2 H, CH₂O), 4.91-4.94 (m, 1 H, 9-OH), 4.87 (s, 2 H, CH₂O), 4.83 (dd, J= 6.3, 5.9 Hz, 1 H, 14- OH), 4.69 (d, J= 5.7 Hz, 1 H, 4-OH), 4.58 (d, J= 6.0 Hz, 2 H, H 14), 4.12-4.18 (m, 1 H, H 5'), 3.97 (s, 3 H, OCH₃), 3.95 (s, 3 H, OCH₃), 3.68-3.75 (m, 1 H, H 3'), 3.43-3.47 (m, 1 H, H 4'), 2.99 (d, J= 18.4 Hz, 1 H, H 10), 2.92 (d, J= 18.4 Hz, 1 H, H 10), 2.20 (br d, J= 14.1 Hz, 1 H, H 8), 2.12 (dd, J= 14.1 Hz, 1 H, H 8), 1.85 (dt, J= 12.8, 3.7 Hz, 1 H, H 2'), 1.47 (dd, J= 12.8, 4.1 Hz, 1 H, H 2'), 1.13 (d, J- 6.5 Hz, 3 H, H 6'); ^I3C NMR [(CD₃)₂SO] δ 213.7 (C 13), 186.4 (C 5), 186.3 (C 12), 160.7 (C 4), 157.0 (C 2'"), 156.0 (C 6), 155.2 (C 11), 154.4 (OCONH), 152.9 (OCONH), 148.2 (C 4"'), 138.4 (C 4"), 136.1 (C 2), 135.4 (C 12a), 134.6 (C 6a), 134.0 (C 10a), 132.2 (C 1"), 131.0 (C 1'"), 128.9 (C 2"'), 128.6 (C 2", C 6"), 119.9 (C 4a), 119.6 (C 1), 118.9 (C 3), 117.9 (C 3", C 5"), 115.4 (C 5'"), 110.7 (C 5a), 110.6 (C 11a), 105.4 (C 3"'), 100.2 (C 1 '), 74.9 (C 9), 69.8 (C 7), 67.9 (C 4'), 66.6 (C 5'), 64.8 (C 14), 63.6 (CH₂O), 60.4 (CH₂O), 56.5 (OCH₃), 56.2 (OCH₃), 47.0 (C 3'), 36.5 (C 8), 32.0 (C 10), 29.7 (C 2'), 16.9 (C 6'); MS (FAB⁺) m/z 902 (MH⁺, 0.2%); Anal. (C₄₄H₄₃N₃O₁₈.H₂O) C, H. N, calc 4.6, found 5.6%.

Example 2G. Preparation of 2-methoxy-4-nitrobenzyl 2-{[(9-amino-5-methyl-4- acridinyl)carbonyl]amino}ethyl(methyl)carbamate (46). 2-Methoxy-4-nitrobenzyl methyl{2-[(trifluoroacetyl)amino]ethyl}carbamate (43). A solution of 2-methoxy-4-nitrobenzyl alcohol (29) (183 mg, 1.0 mmol) and DIEA (0.19 mL, 1.2 mmol) in DCM (2 mL) was added dropwise to a solution of triphosgene (104 mg, 0.35 mmol) in DCM (1.5 mL) over 30 min at °C. The reaction was stirred at 5 °C for 1 h, then a solution of 2,2,2-trifluoro-N-[2-(methylamino)ethyl]acetamide trifluoroacetate (282 mg, 1.0 mmol) and DIEA (0.38 mL, 2.4 mmol) in DCM (2 mL) was added and the solution stirred at 20 °C for 16 h. The solvent was evaporated and the residue purified by chromatography, eluting with 40% EtO Ac/petroleum ether, to give 43 (371 mg, 94%) as a white solid, mp 107-109 °C; Η ΝMR δ 7.86 (dd, J= 8.4, 2.2 Hz, 1 H, H 5), 7.72 (d, J= 2.2 Hz, 1 H, H 3), 7.56 (br s, 1 H, COΝH), 7.44 (d, J= 8.4 Hz, 1 H, H 6), 5.23 (s, 2 H, CH₂O), 3.95 (s, 3 H, OCH₃), 3.58 (br s, 4 H, 2 CH₂Ν), 3.03 (s, 3 H, NCH₃); ¹ C NMR δ 157.7 (C 2), 157.4 (q, J = 37 Hz, COCF₃), 157.1 (OCON), 148.6 (C 4), 132.2 (C 1), 128.1 (C 6), 115.7 (C 5), 115.7 (q, J= 288 Hz, CF₃), 105.2 (C 3), 62.3 (CH₂O), 56.0 (OCH₃), 47.9 (CH₂N), 39.5 (CH₂N), 35.0 (NCH₃); Anal. (C₁₄H₁₆F₃N₃O₆) C, H, N.

2-Methoxy-4-nitrobenzyl 2-aminoethyl(methyl)carbamate (44). A solution of carbamate 43 (948 mg, 2.5 mmol), Cs₂CO₃ (4.0 g, 12.0 mmol) and water (5 mL) in methanol (20 mL) was stirred at 20 °C for 8 h. The pH was adjusted to 10 with 1 M HCI, water (50 mL) was added, and the solution was extracted with DCM (3 50 mL). The combined organic phase was dried and the solvent was evaporated to give 44 (578 mg, 83%) as a colorless oil which was used directly, 'H NMR δ 7.85 (dd, J- 2.0, 8.2 Hz, 1 H, H 5), 7.72 (d, J= 2.0 Hz, 1 H, H 3), 7.47 (d, J- 8.2 Hz, 1 H, H 6), 5.23 (s, 2 H, CH₂O), 3.95 (s, 3 H, OCH₃), 3.37-3.40 (m, 2 H, CH₂), 2.99-3.02 (m, 3 H, CH₃N), 2.87-2.90 (m, 2 H, CH₂), NH₂ not observed; ¹³C NMR δ 153.0, 148.5, 132.9, 128.3, 127.8, 115.7, 105.1, 61.7, 56.0, 52.2, 40.1, 35.2.

2-Methoxy-4-nitrobenzyl 2-{[(9-chloro-5-methyl-4- acridinyl)carbonyl]amino}ethyl(methyl)carbamate (45). A stirred suspension of 5- methyl-9-oxo-9,10-dihydro-4-acridinecarboxylic acid (16) (507 mg, 2.0 mmol) in SOC1- (30 mL) containing DMF (2 drops) was heated gently under reflux until homogeneous and then for a further 45 min. The solution was evaporated below 40 °C, and the residue azeotroped with benzene. The residue was dissolved in DCM (30 mL), cooled to 5 °C, DIEA (1 mL, 6 mmol) and 44 added, and the solution stirred at 20 °C for 30 min. The solvent was evaporated and the residue purified by chromatography, eluting with 75% EtOAc/light petroleum, to give 45 (255 mg, 50 %) as a yellow solid, mp (EtOAc/light petroleum) 60-65°C; Η NMR [(CD₃)₂SO] δ 11.92-11.96 (m, 1 H, NH), 8.91-9.00 (m, 1 H), 8.53-8.61 (m, 1 H), 8.26-8.29 (m, 1 H), 7.66-7.75 ( m, 2 H), 7.51-7.60 (m, 2 H), 7.17-7.30 (m, 2 H), 5.15 (s, 2 H, CH₂O), 3.89 (s, 3 H, OCH₃), 3.72-3.75 (m, 2 H, CH₂), 3.62-3.65 (m, 2 H, CH₂), 3.09 (s, 3 H, CH₃N), 2.75 (s, 3 H, CH₃); ¹³C NMR [(CD₃)₂SO] δ 165.9, 156.3, 146.6, 145.0, 143.3, 135.9, 135.6, 132.4, 131.6, 128.8, 128.7, 128.4, 128.2, 127.7, 127.5, 126.5, 124.2, 123.8, 123.0, 115.5, 104.3, 61.5, 55.8, 49.0, 38.0, 35.2, 18.9.

2-Methoxy-4-nitrobenzyl 2-{[(9-amino-5-methyl-4- acridinyl)carbonyl]amino}ethyl(methyl)carbamate (46). A solution of chloride 45 (100 mg, 0.17 mmol) in dry phenol (1.2 g, 13 mmol) was heated at 50 °C. Dry ammonia was bubbled through the solution while the temperature was raised from 50 to 120°C. Addition of ammonia was continued for 15 min, then the mixture was cooled and diluted with excess 40% aqueous NaOH. Prolonged cooling gave a solid that was purified by chromatography, eluting with 20%MeOH/DCM, to give 46 (80 mg, 92 %) as a yellow solid, mp

(MeOH/DCM) 245-248 °C; 'H NMR [(CD₃)₂SO] δ 12.72-12.74 (m, 1 H, NH), 8.55-8.66 (m, 2 H), 8.28-8.24 (m, 1 H), 8.10-8.14 (m, 2 H), 7.66-7.09 (m, 4 H), 5.00 (s, 2 H, CH₂O), 3.73 (s, 3 H, OCH₃), 3.65 (m, 4 H, 2 CH₂), 2.95 (s, 3 H, CH₃N), 2.51 (s, 3 H, CH₃); ¹³C NMR [(CD₃)₂SO] δ 165.9, 155.7, 155.2, 152.2, 147.1, 146.2, 145.4, 134.3, 134.0, 132.2, 130.9, 127.2, 126.8, 126.6, 121.7, 121.1, 120.4, 114.7, 113.0, 111.7, 104.4, 60.8, 55.7, 48.4, 36.7, 34.3, 18.5. Anal. (C₂₇H_I7N₅O₆) C, H, N.

Example 2H. Preparation of 2-methoxy-4-nitrobenzyl bis(3-{[(5-methyl-4- acridinyl)carbonyl]amino}propyl)carbamate (51). 2,2,2-Trifluoro-N-[3-({3-[(trifluoroacetyl)amino]propyl}amino)propyl]acetamide trifluoroacetate (47). Water (1.2 mL, 70 mmol) was added to a stirred solution of N-(3- aminopropyl)-l,3-propanediamine (4.0 g, 30.5 mmol) and ethyl trifluoroacetate (15.0 g, 105 mmol) in MeCΝ (60 mL) and the solution heated at reflux for 3 h. The solution was cooled, the solvent evaporated, and the residue was triturated with DCM (100 mL). The suspension was filtered to give 47 (1.20 g, 90%) as white solid, mp (DCM) 175-178 °C; Η ΝMR [(CD₃)₂SO] δ 9.55 (s, 2 H, ΝH₂ ⁺), 8.45 (br s, 2 H, 2 CONH), 3.24-3.28 (m, 4 H, 2 CH₂N), 2.90-2.94 (m, 4 H, 2 CH₂N), 1.76-1.84 (m, 4 H, 2 CH₂); Anal. (C₁₂H₁₆F₉N₃O₄) C, H, N.

2-Methoxy-4-nitrobenzyl 3-[(trifluoroacetyl)amino]propyl(6,6,6-trifluoro-5- oxohexyl)carbamate (48). A solution of 2-methoxy-4-nitrobenzyl alcohol (29) (183 mg, 1.0 mmol) and DIEA (0.19 mL, 1.2 mmol) in DCM (2 mL) was added dropwise to a solution of triphosgene (104 mg, 0.35 mmol) in DCM (1.5 mL) over 30 minutes at 5 °C and the solution stirred for 1 h. The solution was added dropwise to a suspension of bistrifluoroacetamide 47 (437 mg, 1.0 mmol) and DIEA (0.38 mL, 2.4 mmol) in DCM (2 mL) and the solution stirred at 20 °C for 16 h. The solvent was evaporated and the residue purified by chromatography, eluting with 40% EtOAc/light petroleum, to give 48 (373 mg, 70%) as a white solid, mp (EtOAc/light petroleum) 133-135°C; 'H NMR [(CD₃)₂SO] δ 9.41 (s, 2 H, 2 CONH), 7.85 (dd, J = 8.0, 2.0 Hz, 1 H, H 5), 7.78 (d, J = 2.0 Hz, 1 H, H 3), 7.50 (d, J= 8.0 Hz, 1 H, H 6), 5.12 (s, 2 H, CH₂O), 3.95 (s, 3 H, OCH₃), 3.15-3.35 (m, 8 H, 4 CH₂N), 1.74 (m, 4 H, 2 CH₂). Anal. (C₁₉H₂₂F₆N₄O₇) C, H, N.

2-Methoxy-4-nitrobenzyl bis(3-{[(5-methyl-4- acridinyl)carbonyl]amino}propyl)carbamate (51). A solution of carbamate 48 (107 mg, 0.2 mmol), Cs₂CO₃ (1.0 g, 3.0 mmol) and water (1 mL) in methanol (4 mL) was stirred at 20 °C for 8 hrs. The pH was adjusted to 10 with 1M HCI, water (50 mL) added, and the solution was extracted with DCM (3 50 mL). The combined organic fraction was dried, the solvent was evaporated to give crude 2-methoxy-4-nitrobenzyl bis(3- aminopropyl)carbamate 49). 4-(lH-Imidazol-l-ylcarbonyl)-5-methylacridine (50) [S. A. Gamage, j. A. Spicer, G. J. Atwell, G. j. Finlay, B. C. Baguley, W. A. Denny, J. Med. Chem., 1999, 42, 2383-2393] (104 mg, 0.36 mmol) was added to a solution of the crude carbamate 49 in TΗF (10 mL) at 5 °C and the reaction mixture was stirred at 20 °C for 8 hrs. The solvent was evaporated, and the residue was purified by chromatography on alumina-90, eluting with 2%MeOΗ/45%EtOAc/DCM, to give 51 (85 mg, 64%) as a yellow solid, mp (EtOAc/DCM) 88-90 °C; 'H NMR δ 11.87 (s, 1 H, NH), 11.81 (s, 1 H, NH), 8.90 (s, 2 H), 8.70 (s, 1 H), 8.67 (s, 1 H), 8.03 (m, 2 H), 7.78 (m, 2 H), 7.58 (m, 4 H), 7.40 (m, 2 H), 7.28 (d, J= 2.0 Hz, 1 H, H 3'"), 7.05 (d, J= 8.4 Hz, 1 H, H 6'"), 6.97 (dd, J= 8.4, 2.0 Hz, 1 H, H 5"'), 5.01 (s, 2 H, CH₂O), 3.71 (m, 7 H), 3.58 (m, 4 H), 2.81 (s, 3 H, CH₃), 2.70 (s, 3 H, CH₃), 2.11 (m, 4 H); ¹³C NMR δ 166.1, 156.3, 155.6, 147.8, 146.9 (2), 146.7, 145.2, 145.1, 137.8, 135.7 (2), 135.3, 135.1 (2), 132.3 (2), 132.2 (2), 130.9, 128.2, 127.9, 126.9 (2), 126.5, 126.3, 126.2, 126.1 (2), 125.7 (2), 125.3 (2), 115.1, 104.2, 61.6, 55.6, 45.8, 45.1, 37.7, 37.1, 29.2, 28.5, 18.9, 18.7; Anal. (C₄₅H₄₂N₆O₇.! ₂H₂O) C, H, N.

Example 21. Preparation of 2-methoxy-4-nitrobenzyl 2-[(5,8-dihydroxy-4-{[2- (methyl{[(2-methoxy-4-nitrobenzyl)oxy]carbonyl}amino)ethyl]amino}-9,1 -dioxo- 9,10-dihydro-l-anthracenyl)amino]ethyl(methyl)carbamate (53). A solution of 1,4- difluoro-5 ,8-dihydroxyanthracene-9, 10-dione (22) ( 1.0 g, 3.6 mmol) and 2-methoxy-4- nitrobenzyl 2-aminoethyl(methyl)carbamate (44) (0.8 g, 2.7 mmol) in pyridine (20 mL) was stirred at 20 °C for 48 h. The solvent was evaporated and residue was purified by column chromatography, eluting with a gradient (50-85%) of EtOAc/DCM, to give: (i) starting material (22) (0.15 g, 15%) and:

(ii) 2-methoxy-4-nitrobenzyl 2-[(4-fluoro-5,8-dihydroxy-9,10-dioxo-9,10-dihydro-l- anthracenyl)amino]ethyl(methyl)carbamate (52) (0.54 g, 37%) as a purple solid mp (EtOAc/DCM) 122-125 °C; 'H NMR δ 13.05-13.77 (m, 2 H, 2 x OH), 9.84-10.07 (br d, 1 H, NH), 6.99-7.83 (m, 7 H), 5.27 (s, 2 H, CH₂O), 3.95 (s, 3 H, OCH₃), 3.63 (m, 4 H), 3.09 (s, 3 H, NCH₃); HRMS (FAB⁺) calc. for C₂₆H₂₂FN₃O₉ (M⁺) m/z 539.1340, found 539.1331; and:

(iii) 53 (120 mg, 5%) as a blue solid, 'H NMR δ 13.15-13.36 (m, 2 H, 2 x OH), 10.29- 10.42 (m, 2 H, 2 x NH), 6.97-7.82 (m, 10 H), 5.26 (s, 2 H, CH₂O), 5.12 (s, 2 H, CH₂O), 3.95 (s, 3 H, OCH₃), 2.78 (s, 3 H, OCH₃), 3.50 (br, 8 H), 3.05 (s, 6 H, 2 x NCH₃); HRMS (FAB⁺) calc. for C₃₈H₃₈N₆O₁₄ (M⁺) m/z 802.2446, found 802.2446.

Example 2J. Preparation of 2-methoxy-4-nitrobenzyl 2-{[5,8-dihydroxy-4-({2-[(2- hydroxyethyl)amino]ethyl}amino)-9,10-dioxo-9,10-dihydro-l- anthracenyl]amino}ethyl(methyl)carbamate (55).

A solution of fluoride 52 (0.54 g, 1.0 mmol) and 2-(2-aminoethylamino)ethanol (2.0 g, 19 mmol) in pyridine (20 mL) was stirred at 20 °C for 54 h. The solvent was evaporated and residue was purified by column chromatography, eluting with a gradient (50-85%) of EtOAc/light petroleum followed by (2- 10%) MeOH/EtOAc, to give:

(i) 2-methoxy-4-nitrobenzyl 2- {[8,1 l-dihydroxy-4-(2-hydroxyethyl)-7,12-dioxo- l,2,3,4,7,12-hexahydronaphtho[2,3- ]quinoxalin-6-yl]amino}ethyl(methyl)carbamate (54) (0.1 g, 16%) as a blue solid; mp (DCM/light petroleum) 221-224 °C; Η NMR δ 13.43- 14.25 (m, 2 H, 2 x OH), 10.89-11.29 (m, 2 H, 2 NH), 6.96-7.77 (m, 6 H), 6.20 (s, 1 H), 4.80 (s, 2 H, CH₂O), 3.94 (s, 3 H, OCH₃), 3.65 (m, 12 H), 2.97 (s, 3 H, NCH₃); and:

(ii) 55 (0.45 g, 72%) as a blue oil, Η NMR δ 13.26-13.51 (m, 2 H, 2 OH), 10.44-10.50 (m, 2 H, 2 x NH), 7.02-7.88 (m, 7 H), 5.28 (s, 2 H, CH₂O), 3.96 (s, 3 H, OCH₃), 3.39-3.65 (m, 12 H), 3.07 (s, 3 H, NCH₃), NH, OH not observed; HRMS (FAB⁺) calc. for C₃₀H₃₄N₅O₁₀ (MH⁺) m/z 624.2306, found 624.2297..

Example 3A. Preparation of l-(4-nitrophenyl)ethyl 4-[bis(2- chloroethyl)amino]phenylcarbamate (59). l-(4-Nitrophenyl)ethyl 4-[bis(2-hydroxyethyl)amino]phenyIcarbamate (58). Pyridine (320 mL, 3.95 mmol) was added dropwise to a stirred solution of 1 -(4-nitrophenyl)ethanol 56 (660 mg, 3.95 mmol) and triphosgene (410 mg, 1.38 mmol) in THF (50 mL) at 5 °C and the suspension stiπed at 5 °C for 1 h. A solution of N'N'-bis(2-hydroxyethyl)-l,4- benzenediamine (57) (prepared by catalytic hydrogenation of NN-bis-(2-hydroxyethyl)-4- nitroaniline (30) (0.85 g, 4.34 mmol) with Pd/C under H₂ (60 psi) in EtOH) in THF (10 mL) and DMF (20 mL) was added and the mixture stirred at 20 °C for 16 h. The solvent was evaporated and the residue purified by chromatography, eluting with EtOAc to give 58 (1.01 g, 66 %) as a brown oil, Η ΝMR δ 8.19 (d, J= 8.8 Hz, 2 H, H 3', H 5'), 7.52 (br d, J = 8.8 Hz, 2 H, H 2', H 6'), 7.16 (d, J= 9.0 Hz, 2 H, H 2, H 6), 6.69 (br s, 1 H, OCOΝH), 6.62 (d, J= 9.0 Hz, 2 H, H 3, H 5), 5.90 (q, J= 6.6 Hz, 1 H, CHO), 3.76-3.80 (m, 4 H, 2 CH₂O), 3.55 (br s, 2 H, 2 OH), 3.48-3.51 (m, 4 H, 2 x CH₂Ν), 1.58 (d, J= 6.6 Hz, 3 H, CH₃); ^,3C NMR δ 153.1, 149.4, 147.4, 144.9, 127.3, 126.6 (2), 123.8 (2), 121.4 (2), 113.3 (2), 71.9, 60.6 (2), 55.3 (2), 22.5; MS (FAB⁺) m/z 390 (MH⁺, 25%); HRMS (FAB⁺) calc. for C₁₉H₂₄N₃O₆ (MH⁺) m/z 390.1665, found 390.1656.

l-(4-nitrophenyl)ethyl 4-[bis(2-chloroethyl)amino]phenylcarbamate (59). Methane- sulphonyl chloride (600 μL, 7.7 mmol) was added dropwise to a stirred solution of 58 (1.0 g, 2.57 mmol) in pyridine (20 mL) at 20 °C and the solution stirred for 1 h. The solvent was evaporated and the residue partitioned between DCM/water (100 mL). The aqueous fraction was extracted with DCM (2 x 50 mL) and the combined organic fraction washed with brine (50 mL), dried and the solvent evaporated. The residue was dissolved in DMF (15 mL), LiCl (0.65 g, 15.4 mmol) added, and the mixture stirred at 80 °C for 3 h. The solvent was evaporated and the residue partitioned between EtOAc/water (200 mL). The aqueous fraction was extracted with EtOAc (2 50 mL). The combined organic fraction was washed with brine (50 mL), dried, and the solvent evaporated. The residue was purified by chromatography, eluting with 25% EtOAc/light petroleum, to give 59 (1.0 g, 92 %) as a tan oil, 'H NMR δ 8.20 (ddd, J= 8.9, 2.2, 1.9 Hz, 2 H, H 3', H 5'), 7.53 (br d, J= 8.9 Hz, 2 H, H 2', H 6'), 7.23 (br d, J= 9.0 Hz, 2 H, H 2, H 6), 6.64 (ddd, J= 9.0, 3.4, 2.1 Hz, 2 H, H 3, H 5), 6.61 (br s, 1 H, OCONH), 5.92 (q, J= 6.6 Hz, 1 H, CHO), 3.67-3.71 (m, 4 H, 2 x CH₂N), 3.58-3.62 (m, 4 H, 2 x CH-C1), 1.59 (d, J= 6.6 Hz, 3 H, CH₃); ¹³C NMR δ 152.9, 149.3, 147.4, 142.9, 128.0, 126.6 (2), 123.8 (2), 121.4 (2), 112.7 (2), 71.9, 53.6 (2), 40.4 (2), 22.4; MS (FAB⁺) m/z 429 (M+, 5%), 427 (10), 425 (15); HRMS (FAB⁺) calc. for C₁₉H₂₁ ³⁵Cl₂N₃O₄ (M⁺) m/z 425.0909, found 425.0901 ; calc. for C₁₉H₂₁ ³⁵Cl³⁷ClN₃O₄ (M⁺) m/z 427.0880, found 427.0882; calc. for C₁₉H₂₁ ⁷Cl₂N₃O₄ (M⁺) m/z 429.0850, found 429.0868.

Example 3B. Preparation of l-(4-nitrophenyl)ethyl l-(chloromethyl)-3-[(5,6,7- trimethoxy-lH-indol-2-yl)carbonyl]-2,3-dihydro-lH-benzo[e]indol-5-ylcarbamate (60). A solution of of l-(4-nitrophenyl)ethanol (56) (18 mg, 0.11 mmol) in DCM (2 mL) was added dropwise to a stirred solution of triphosgene (16 mg, 0.054 mmol) and pyridine (9 μL, 0.11 mmol) in DCM (2 mL) at 20 °C. The mixture was stirred at 20 °C for 2 h, the solvent evaporated and the residue dissolved in THF (5 mL). A solution of 1 [G. J. Atwell, W. R. Wilson, W. A. Denny, Bioorg. Med. Chem. Lett., 1997, 7, 1483] (50 mg, 0.11 mmol) in THF ( 5 mL) was added and the solution stirred at 20 °C for 16 h. The mixture was partitioned between EtOAc (50 mL) and sat. aq. KHCO₃ solution, the organic fraction dried and the solvent evaporated. The residue was purified by chromatography, eluting with 25% EtOAc/light petroleum to give: (i) 60 (23 mg, 32%) as a tan solid mp (EtOAc/light petroleum) 175-178 °C; 'H NMR δ 9.49 (s, 1 H, indole-NH), 8.88 (s, 1 H, OCONH), 8.18 (d, J= 7.6 Hz, 2 H, H 3", H 5"), 7.88 (d, J= 8.3 Hz, 1 H, H 6), 7.78 (d, J= 8.3 Hz, 1 H, H 9), 7.52-7.58 (m, 3 H, H 8, H 2", H 6"), 7.45 (dd, J= 7.8, 7.5 Hz, 1 H, H 7), 7.16 (br s, 1 H, H 4), 7.00 (d, J = 1.90 Hz, 1 H, H 3'), 6.87 (s, 1 H, H 4'), 6.00 (q, J = 6.6 Hz, 1 H, CHO), 4.80 (dd, J= 10.7, 1.2 Hz, 1 H, H 2), 4.65 (dd, J= 10.7, 8.8 Hz, 1 H, H 2), 4.11-4.17 (m, 1 H, CH₂C1), 4.08 (s, 3 H, OCH₃), 3.93-3.97 (m, 4 H, OCH₃, CH₂C1), 3.91 (s, 3 H, OCH₃), 3.45 (dt, J= 10.7, 3.3 Hz, 1 H, H 1), 1.65 (br d, J= 6.6 Hz, 3 H, CH₃); ^I3C NMR δ 160.3, 153.4, 150.2, 149.0, 147.5, 141.6, 140.6, 138.9, 133.8, 130.4, 129.7, 129.6, 127.4, 126.8 (2), 125.6, 125.0, 123.9, 123.8 (2), 123.6, 123.1, 122.3, 121.7, 106.5, 97.6, 72.6, 61.5, 61.1, 56.3, 54.9, 45.8, 43.4, 22.6; MS (FAB⁺) m/z 659 (MH⁺, 6%), 658 (6), 510 (1), 234 (10); HRMS calc. for C₃₄H₃₂ ³⁵ClN₄O₈ (MH⁺) m/z 659.1909, found 659.1881; calc for C₃₄H₃₂₃₇ClN₄O₈ (MH⁺) m/z 661.1879, found 661.1882; Anal. (C₃₄H₃₁ClN₄O₈) C, H, N: and (ii) starting material (1) (30 mg, 60 %).

Example 3C. Preparation of l-(2-methoxy-4-nitrophenyl)ethyl 4-[bis(2- chloroethyl)amino]phenylcarbamate (64). 2-Methoxy-4-nitrobenzaldehyde (61). PCC (0.76 g, 3.52 mmol) and 4A molecular sieves (1.0 g) were added to a stirred solution of 2-methoxy-4-nitrobenzyl alcohol 29 (0.43 g, 2.35 mmol) in DCM (100 mL) and the suspension stirred at 20 °C for 1 h. The suspension was diluted with diethyl ether (150 mL) and the suspension filtered through Celite^®, washed with diethyl ether (2 20 mL). The combined organic fraction was evaporated and the residue purified by chromatography, eluting with 50% EtOAc/light petroleum, to give 61 (0.42 g, 98%) as white crystals, mp (EtOAc/light petroleum) 117-119 °C; Η NMR δ 10.52 (s, 1 H, CHO), 7.98 (br d, J= 8.2 Hz, 1 H, H 5), 7.85-7.89 (m, 2 H, H 3, H 6), 4.07 (s, 3 H, OCH₃); ¹³C NMR δ 188.2 (CHO), 161.8 (C 2), 152.2 (C 4), 129.5 (C 6), 128.6 (C 1), 115.6 (C 5), 107.2 (C 5), 56.4 (OCH₃); Anal. (C₈H₇NO₄) C, H, N.

l-(2-Methoxy-4-nitrophenyl)ethanol (62). A solution of MeMgBr (3 M in diethyl ether: 3.64 mL, 10.9 mmol) was added dropwise to a stirred solution of 61 (1.80 g, 9.93 mmol) in THF (100 mL) at -78 °C and the solution stirred at -78 °C for 20 min. The solution was quenched with sat. aq NH₄C1 solution (5 mL) and allowed to warm to 20 °C. The solvent was evaporated and the residue purified by chromatography, eluting with 20% EtOAc/light petroleum, to give (i) starting material (0.38 g, 21%) and (ii) 62 (0.88 g, 45%) as a white solid, mp (EtOAc/light petroleum) 63-65 °C; ^!H NMR δ 7.86 (dd, J= 8.4, 2.1 Hz, 1 H, H 5), 7.70 (d, J= 2.1 Hz, 1 H, H 3), 7.58 (d, J= 8.4 Hz, 1 H, H 6), 5.19 (dq, J= 6.4, 4.7 Hz, 1 H, CHOCO), 3.96 (s, 3 H, OCH₃), 2.34 (d, J= 4.7 Hz, 1 H, OH), 1.48 (d, J= 6.4 Hz, 3 H, CH₃); ¹³C NMR δ 156.4 (C 2), 148.0 (C 4), 141.3 (C 1), 126.3 (C 6), 116.2 (C 5), 105.3 (C 3), 65.5 (CHOCO), 55.9 (OCH₃), 23.1 (CH₃); Anal. (C₉H_πNO₄) C, H, N.

l-(2-Methoxy-4-nitrophenyl)ethyl 4- [bis(2-hydroxyethyl)amino] phenylcarbamate (63). Pyridine (178 μL, 2.20 mmol) was added dropwise to a stirred solution of ethanol 62 (430 mg, 2.20 mmol) and triphosgene (229 mg, 0.77 mmol) in THF (50 mL) at 5 °C and the suspension stirred at 5 °C for 1 h. A solution of N'N¹-bis(2-hydroxyethyl)-l,4- benzenediamine 57 (476 mg, 2.42 mmol) with Pd/C under H₂ (60 psi) in EtOH) in THF (10 mL) and DMF (10 mL) was added and the mixture stirred at 20 °C for 10 days. The solvent was evaporated and the residue purified by chromatography, eluting with EtOAc to give 63 (860 mg, 93%) as a tan foam, 'H ΝMR δ 9.42 (br s, 1 H, OCOΝH), 7.91 (dd, J= 8.4, 2.1 Hz, 1 H, H 5), 7.79 (d, J= 2.1 Hz, 1 H, H 3), 7.60 (d, J= 8.4 Hz, 1 H, H 6), 7.18 (d, J= 9.0 Hz, 2 H, H 2', H 6'), 6.59 (d, J= 9.0 Hz, 2 H, H 3',H 5'), 6.00 (q, J = 6.5 Hz, 1 H, CHOCO), 4.69 (br s, 2 H, 2 x OH), 3.98 (s, 3 H, OCH₃), 3.48-3.53 (m, 4 H, 2 x CH₂O), 3.32-3.37 (m, 4 H, 2 CH₂N), 1.46 (d, J= 6.5 Hz, 3 H, CH₃); ¹³C NMR δ 155.7 (C 2), 152.6 (OCONH), 147.4 (C 4), 144.0 (C 4'), 138.7 (C 1'), 127.3 (C 1), 125.7 (C 6), 120.1 (C 2', C 6'), 115.8 (C 5), 111.4 (C 3', C 5'), 105.7 (C 3), 66.0 (CHOCO), 59.7 (2 x CH₂O), 58.2 (OCH₃), 53.4 (2 CH₂N), 20.8 (CH₃); MS (FAB⁺) m/z 420 (MH⁺, 30%); HRMS (FAB⁺) calc. for C₂₀H₂₆N₃O₇ (MH⁺) m/z 420.1771, found 420.1761.

l-(2-Methoxy-4-nitrophenyl)ethyl 4-[bis(2-chloroethyl)amino]phenylcarbamate (64). Methanesulphonyl chloride (404 μL, 5.2 mmol) was added dropwise to a stirred solution of 63 (0.73 g, 1.74 mmol) in pyridine (20 mL) at 20 °C and the solution stirred for 1 h. The solvent was evaporated and the residue partitioned between DCM/water (100 mL). The aqueous fraction was extracted with DCM (2 x 50 mL) and the combined organic fraction washed with brine (50 mL), dried and the solvent evaporated. The residue was dissolved in DMF (20 mL), LiCl (0.44 g, 10.4 mmol) added, and the mixture stirred at 80 °C for 3 h. The solvent was evaporated and the residue partitioned between EtO Ac/water (200 mL). The aqueous fraction was extracted with EtOAc (2 50 mL). The combined organic fraction was washed with brine (50 mL), dried, and the solvent evaporated. The residue was purified by chromatography, eluting with 20% EtOAc/light petroleum, to give 64 (0.53 g, 67 %) as a tan foam, Η NMR δ 7.84 (dd, J= 8.4, 1.9 Hz, 1 H, H 5), 7.71 (d, J= 1.9 Hz, 1 H, H 3), 7.50 (d, J= 8.4 Hz, 1 H, H 6), 7.24 (br d, J= 9.0 Hz, 2 H, H T, H 6'), 6.64 (d, J = 9.0 Hz, 2 H, H 3', H 5'), 6.62 (br s, 1 H, OCONH), 6.19 (q, J= 6.5 Hz, 1 H, CHOCO), 3.95 (s, 3 H, OCH₃), 3.69 (dd, J= 7.0, 6.4 Hz, 4 H, 2 x CH₂N), 3.60 (dd, J= 7.0, 6.4 Hz, 4 H, 2 x CH₂C1), 1.52 (d, J= 6.5 Hz, 3 H, CH₃); ¹³C NMR δ 156.0 (C 2), 152.8 (OCONH), 148.1 (C 4), 142.9 (C 4'), 138.5 (C 1 '), 128.3 (C 1), 125.8 (C 6), 121.3 (C 2', C 6'), 116.0 (C 5), 112.8 (C 3', C 5'), 105.5 (C 3), 67.6 (CHOCO), 56.0 (OCH₃), 53.7 (2 x CH₂N), 40.5 (2 x CH₂C1), 21.2 (CH₃); MS m/z 459 (M⁺, 2%), 457 (M\ 12), 455 (M⁺, 16), 276 (20), 231 (100); HRMS calc. for C₂₀H₂₃ ³⁵C1₂N₃O₅ (M⁺) m/z 455.1015, found 455.1017; calc. for C₂₀H₂₃ ³⁵C1³⁷C1N₃O₅ (M⁺) m/z 457.0985, found 457.0990; calc. for C₂₀H₂₃ ³⁷C1₂N₃O₅ (M⁺) m/z 459.0956, found 459.0972.

Example 4A. Preparation of 2-(2-hydroxyethoxy)-4-nitrobenzyI l-(chloromethyl)-3- [(5,6,7-trimethoxy-lH-indol-2-yl)carbonyl]-2,3-dihydro-lH-benzo[e]indol-5- ylcarbamate (70).

2-Bromoethyl ter/-butyl(dimethyl)silyl ether (65). TBDMS triflate (5.0 mL, 21.8 mmol) was added dropwise to a stirred solution of bromoethanol (1.40 mL, 19.8 mmol) and pyridine (2.4 mL, 29.7 mmol) in DCM (50 mL) at 5 °C and the solution stirred at 20 °C for 16 h. MeOH (5 mL) was carefully added, the solution stirred for 5 min and poured into sat. aq. KHCO₃ (150 mL). The mixture was extracted with DCM (3 x 80 mL), the combined organic fraction dried, and the solvent evaporated. Chromatography of the residue, eluting with 10% EtOAc/light petroleum, gave 65 (3.95 g, 83%) as a colourless oil, 'H NMR δ 3.88 (t, J= 6.6 Hz, 2 H, CH₂O), 3.40 (t, J= 6.6 Hz, 2 H, CH₂Br), 0.90 (s, 9 H, SiC(CH₃)₃), 0.08 (s, 6 H, Si(CH₃)₂); ¹³C NMR δ 63.5 (CH₂O), 33.3 (CH₂Br), 25.8 (SiC(CH₃)₃), 18.3 (SiC(CH₃)₃), -5.3 (Si(CH₃)₂); MS (Cl, NH₃) m/z 241 (MH\ 1%), 239 (MH\ 1%), 225 (2), 223 (2), 183 (55), 181 (55), 139 (100); HRMS (Cl, NH₃) calc for C₈H₂₀ ⁷⁹BrOSi (MH⁺) m/z 239.0467; found 239.0460; calc for C₈H₂₀ ⁸¹BrOSi (MH⁺) m/z 241.0446; found 241.0450.

Methyl 2-(2-{[tert-butyl(dimethyl)silyl]oxy}ethoxy)-4-nitrobenzoate (67). A mixture of methyl 2-hydroxy-4-nitrobenzoate (66) (0.55 g, 2.79 mmol) and K₂CO₃ (0.58 g, 4.19 mmol) in DMF (15 mL) was stirred at 20 °C for 30 min. A solution of 65 (1.00 g, 4.19 mmol) in DMF (5 mL) was added and the mixture was stirred at 100 °C for 4 h. The solvent was evaporated and the residue partitioned between EtOAc (100 mL) and water (100 mL). The organic fraction was washed with water (2 50 mL), brine (50 mL), dried, and the solvent evaporated. The residue was purified by chromatography.eluting with 20% EtOAc/light petroleum, to give 67 (0.76 g, 77%) as a white solid, mp (EtOAc/light petroleum) 47-48 °C; Η NMR δ 7.89 (d, J= 1.3 Hz, 1 H, H 3), 7.81-7.85 (m, 2 H, H 5, H 6), 4.24 (t, J= 5.0 Hz, 2 H, CH₂O), 4.03 (t, J= 5.0 Hz, 2 H, CH₂O), 3.92 (s, 3 H, OCH₃), 0.88 (s, 9 H, SiC(CH₃)₃), 0.08 (s, 6 H, Si(CH₃)₂); ¹³C NMR (CDC1₃) δ 165.5 (CO₂), 158.6 (C 2), 150.4 (C 4), 131.8 (C 6), 126.7 (C 1), 115.0 (C 5), 108.3 (C 3), 71.1 (CH₂O), 61.7 (CH₂O), 52.5 (OCH₃), 25.7 (SiC(CH₃)₃), 18.3 (SiC(CH₃)₃), -5.5 (Si(CH₃)₂); Anal. (C₁₆H₂₅NO₆Si) C, H, N.

[2-(2- { [ rf-Butyl(dimethyl)silyl] oxy } ethoxy)-4-nitrophenyl] methanol (68) . DIBALH (1M in DCM, 6.7 mL, 6.7 mmol) was added dropwise to a stirred solution of ester 67 (0.72 g, 2.02 mmol) in THF (50 mL) at 5 °C and the solution stirred at 5 °C for 1 h. The solution was poured into a solution of potassium sodium tartrate (1 M, 50 mL) and stirred vigorously for 30 min. The mixture was extracted with EtOAc (3 x 50 mL), the combined organic fraction washed with water (50 mL), brine (50 mL), dried and the solvent was evaporated. The residue was purified by chromatography, eluting with 20% EtOAc/light petroleum, to give 68 (0.64 g, 97%) as a white solid, mp (EtOAc/light petroleum) 89-90 °C; 'H NMR δ 7.85 (dd, J- 8.2, 2.1 Hz, 1 H, H 5), 7.74 (d, J= 2.1 Hz, 1 H, H 3), 7.46 (d, J = 8.2 Hz, 1 H, H 6), 4.75 (s, 2 H, CH₂O), 4.21 (dd, J= 4.9, 4.4 Hz, 2 H, CH₂O), 4.01 dd, J = 4.9, 4.4 Hz, 2 H, CH₂O), 2.84 (br s, 1 H, OH), 0.90 (s, 9 H, SiC(CH₃)₃), 0.06 (s, 6 H, Si(CH₃)₂); ¹³C NMR δ 157.0 (C 2), 148.3 (C 4), 137.1 (C 1), 128.4 (C 6), 116.3 (C 5), 106.8 (C 3), 70.5 (CH₂O), 61.6 (CH₂O), 61.3 (CH-O), 25.8 (SiC(CH₃)₃), 18.3 (SiC(CH₃)₃), -5.4 (Si(CH₃)₂); Anal. (C₁₅H₂₅NO₅Si) C, H, N.

2-(2-{[tert-Butyl(dimethyl)silyl]oxy}ethoxy)-4-nitrobenzyl l-(chloromethyl)-3-[(5,6,7- trimethoxy-lH-indol-2-yl)carbonyl]-2,3-dihydro-lH-benzo[e]indol-5-ylcarbamate

(69). A solution of triphosgene (24 mg, 80 μmol) in DCM (2 mL) was added dropwise to a stirred solution of amine 1 [G. J. Atwell, W. R. Wilson, W. A. Denny, Bioorg. Med. Chem. Lett., 1997, 7, 1483] (107 mg, 230 μmol) and Et₃N (64 μL, 460 μmol) in DCM (20 mL) and stirred at 20 °C for 2 h. A solution of [2-(2-{[tert-butyl(dimethyl)silyl]oxy}ethoxy)-4- nitrophenyl]methanol (68) (83 mg, 253 μmol) in DCM (5 mL) was added, followed by nBu₂Sn(OAc)₂ (2 drops) and the solution stirred at 20 °C for 24 h. The solvent was evaporated and the residue purified by chromatography, eluting with a gradient (0-20%) EtOAc/DCM, to give 69 (177 mg, 94%) as a white solid, mp (EtOAc/light petroleum) 182- 185 °C; Η NMR δ 9.45 (s, 1 H, indole-NH), 8.93 (s, 1 H, OCONH), 7.92 (d, J= 8.5 Hz, 1 H, H 6), 7.76-7.83 (m, 3 H, H 9, H 3", H 5"), 7.53-7.60 (m, 2 H, H 8, H 6"), 7.47 (ddd, J = 8.5, 7.1, 0.8 Hz, 1 H, H 7), 7.13 (br s, 1 H, H 4), 7.01 (d, J= 2.2 Hz, 1 H, H 3'), 6.88 (s, 1 H, H 4'), 5.39 (s, 2 H, CH₂O), 4.81 (dd, J= 10.7, 1.8 Hz, 1 H, H 2), 4.67 (dd, J= 10.7, 8.7 Hz, 1 H, H 2), 4.21 (br dd, J= 5.0, 4.8 Hz, 2 H, CH₂O), 4.15-4.18 (m, 1 H, H 1), 4.09 (s, 3 H, OCH₃), 4.02 (br d, J= 5.0, 4.8 Hz, 2 H, CH₂O), 3.97 (d, J= 11.5, 3.1 Hz, 1 H, CH₂C1), 3.95 (s, 3 H, OCH₃), 3.92 (s, 3 H, OCH₃), 3.48 (dd, J= 11.5, 10.9 Hz, 1 H, CH₂C1), 0.90 (s, 9 H, SiC(CH₃)₃), 0.10 (s, 6 H, Si(CH₃)₂); ¹³C NMR δ 160.3 (CO), 156.7 (C 2"), 154.0 (OCONH), 150.2 (C 5'), 148.5 (C 4"), 141.7 (C 3a), 140.6 (C 6'), 138.9 (C 7'), 133.8 (C 5), 132.3 (C 1"), 129.7 (C 2'), 129.6 (C 9a), 128.7 (C 6"), 127.5 (C 8), 125.6 (C 7a'), 125.0 (C 7), 123.6 (C 3a'), 123.1 (C 9), 122.4 (C 6, C 9b), 121.8 (C 5a), 1 15.8 (C 5"), 1 12.8 (C 4), 106.5 (C 3', C 3"), 97.7 (C 4'), 70.7 (CH₂O), 61.8 (CH₂O), 61.7 (CH₂O), 61.5 (OCH₃), 61.1 (OCH₃), 56.3 (OCH₃), 54.9 (C 2), 45.8 (CH₂C1), 43.5 (C 1), 25.8 (SiC(CH₃)₃), 18.3 ; (SiC(CH₃)₃), -5.4 (Si(CH₃)₂); MS (FAB⁺) m/z 819 (MH⁺, 25%), 821 (MH⁺, 12); HRMS (FAB⁺) calcd for C₄₁H₄₈ ³⁵ClN₄O₁₀Si (MH⁺) m/z 819.2828, found 819.2804; calc. for C₄₁H₄₈ ³⁷ClN₄O₁₀Si (MH⁺) m/z 821.2799, found 821.2803; Anal. (C₄₁H₄₇ClN₄O₁₀Si) C, H, N.

2-(2-Hydroxyethoxy)-4-nitrobenzyl l-(chloromethyl)-3-[(5,6,7-trimethoxy-l - ndol-2- yl)carbonyl]-2,3-dihydro-lH-benzo[e]indol-5-ylcarbamate (70). 1 M HCI (0.4 mL, 400 μmol) was added to a stirred solution of silyl ether 69 (157 mg, 192 μmol) in MeOH (5 mL) and the solution stirred at 20 °C for 1 h. The solvent was evaporated and the residue partitoned between EtOAc (50 mL) and water (50 mL). The organic fraction was washed with water (50 mL), brine (25 mL), dried, and the solvent evaporated. The residue was purified by chromatography, eluting with a gradient (20-50%) of EtOAc/light petroleum, to give 70 (119 mg, 88%) as a hygroscopic white solid, 'H NMR δ 9.72 (s, 1 H, indole-NH), 8.80 (s, 1 H, OCONH), 7.86 (d, J= 8.5 Hz, 1 H, H 6), 7.79 (br d, J= 8.1 Hz, 1 H, H 5"), 7.67-7.73 (m, 2 H, H 9, H 3"), 7.47-7.53 (m, 3 H, H 4, H 8, H 6"), 7.37 (ddd, J= 8.5, 7.1, 0.8 Hz, 1 H, H 7), 6.97 (d, J= 2.2 Hz, 1 H, H 3'), 6.87 (s, 1 H, H 4'), 5.40 (s, 2 H, CH₂O), 4.73 (dd, J= 10.7, 1.6 Hz, 1 H, H 2), 4.59 (dd, J= 10.7, 8.7 Hz, 1 H, H 2), 4.21 (br dd, J= 4.6, 4.0 Hz, 2 H, CH₂O), 4.07-4.11 (m, 4 H, H 1, OCH₃), 4.00-4.04 (m, 2 H, CH₂O), 3.95 (s, 3 H, OCH₃), 3.92 (s, 3 H, OCH₃), 3.85 (d, J= 11.3, 3.0 Hz, 1 H, CH₂C1), 3.39 (br s, 1 H, OH), 3.28 (dd, J= 11.3, 10.9 Hz, 1 H, CH₂C1); ¹³C NMR δ 160.5 (CO), 157.2 (C 2"), 154.4 (OCONH), 150.2 (C 5'), 148.9 (C 4"), 141.4 (C 3a), 140.6 (C 6'), 138.9 (C 7'), 133.8 (C 5), 131.9 (C 1"), 130.3 (C 6"), 129.6 (C 2', C 9a), 127.4 (C 8), 125.8 (C 7a'), 125.0 (C 7),

123.6 (C 3a'), 123.0 (C 9), 122.5 (C 6, C 9b), 121.9 (C 5a), 115.9 (C 5"), 112.8 (C 4),

106.7 (C 3'), 106.6 (C 3"), 97.7 (C 4'), 70.7 (CH₂O), 62.0 (CH₂O), 61.5 (OCH₃), 61.1 (OCH₃), 60.9 (CH₂O), 56.3 (OCH₃), 55.1 (C 2), 45.6 (CH₂C1), 43.3 (C 1); MS (FAB⁺) m/z 707 (MH⁺, 5%), 705 (MH⁺, 14); HRMS (FAB⁺) calcd for C₃₅H₃₄ ³⁵C1N₄O₁₀ (MH⁺) m/z

705.1964, found 705.1919; calc. for C₃₅H₃₄ ⁷C1N₄O₁₀ (MH⁺) m/z 707.1934, found 707.1931; Anal. (C₃₅H₃₃C1N₄O₁₀) C, H, N. Example 4B. Preparation of 2-(2-methoxyethoxy)-4-nitrobenzyl l-(chloromethyl)-3- [(5,6,7-trimethoxy-lH-indol-2-yl)carbonyl]-2,3-dihydro-lH-benzo[e]indol-5- ylcarbamate (73). Methyl 2-(2-methoxyethoxy)-4-nitrobenzoate (71). A mixture of methyl 2-hydroxy-4- nitrobenzoate (66) (1.0 g, 5.07 mmol) and K₂CO₃ (1.05 g, 7.61 mmol) in DMF (25 mL) was stirred at 20 °C for 30 min. A solution of 2-bromoethyl methyl ether (0.72 mL, 7.61 mmol) in DMF (3 mL) was added and the mixture was stirred at 100 °C for 4 h. The solvent was evaporated and the residue partitioned between EtOAc (100 mL) and water (100 mL). The organic fraction was washed with water (2 50 mL), brine (50 mL), dried, and the solvent evaporated. The residue was purified by chromatography,eluting with 30% EtOAc/light petroleum, to give 71 (1.27 g, 98%) as a white solid, mp (EtOAc/light petroleum) 45-46 °C; Η NMR δ 7.90 (d, J= 8.3 Hz, 1 H, H 6), 7.82-7.86 (m, 2 H, H 3, H 5), 4.28-4.30 (m, 2 H, CH₂O), 3.93 (s, 3 H, OCH₃), 3.82-3.87 (m, 2 H, CH₂O), 3.48 (s, 3 H, OCH₃); ^,3C NMR δ 165.1 (CO₂), 158.6 (C 2), 150.6 (C 4), 132.1 (C 6), 126.4 (C 1), 115.2 (C 5), 108.4 (C 3), 70.5 (CH₂O), 69.4 (CH₂O), 59.4 (OCH₃), 52.5 (OCH₃); Anal. (C„H₁₃NO₆) C, H, N.

2-[2-(Methoxy)ethoxy]-4-nitrobenzyI alcohol (72). DIBALH (1 M in DCM, 16.4 mL, 16.4 mmol) was added dropwise to a stirred solution of ester 71 (1.27 g, 4.97 mmol) in THF (100 mL) at 5 °C and the solution stirred at 5 °C for 1 h. The solution was poured into a solution of potassium sodium tartrate (1 M, 100 mL) and stirred vigorously for 30 min. The mixture was extracted with EtOAc (2 x 100 mL), the combined organic fraction washed with water (50 mL), brine (50 mL), dried and the solvent was evaporated. The residue was purified by chromatography, eluting with a gradient (30-50%) of EtOAc/light petroleum, to give 72 (1.03 g, 91%) as a white solid, mp (EtOAc/light petroleum) 89-90.5 °C; Η NMR δ 7.86 (dd, J = 8.2, 2.1 Hz, 1 H, H 5), 7.72 (d, J = 2.1 Hz, 1 H, H 3), 7.47 (d, J = 8.2 Hz, 1 H, H 6), 4.74 (br s, 2 H, CH₂O), 4.26-4.29 (m, 2 H, CH₂O), 3.78-3.80 (m, 2 H, CH₂O), 3.45 (s, 3 H, OCH₃), 3.10 (br s, 1 H, OH); ^,3C NMR δ 156.8 (C 2), 148.2 (C 4), 137.5 (C 1), 128.6 (C 6), 116.5 (C 5), 107.0 (C 3), 70.5 (CH₂O), 68.4 (CH₂O), 61.1 (CH₂O), 59.1 (OCH₃); Anal. (C₁₀H₁₃NO₅) C, H, N.

2-(2-Methoxyethoxy)-4-nitrobenzyl l-(chloromethyl)-3-[(5,6,7-trimethoxy-lH-indol-2- yl)carbonyl]-2,3-dihydro-lH-benzo[e]indol-5-ylcarbamate (73). A solution of triphosgene (12 mg, 40 μmol) in DCM (2 mL) was added dropwise to a stirred solution of amine 1 [G. J. Atwell, W. R. Wilson, W. A. Denny, Bioorg. Med. Chem. Lett., 1997, 7, 1483] (53 mg, 1 14 μmol) and Et₃N (32 μL, 228 μmol) in DCM (10 mL) and stirred at 20 °C for 2 h. A solution of 2-[2-(methoxy)ethoxy]-4-nitrobenzyl alcohol 72 (28 mg, 125 μmol) in DCM (2 mL) was added, followed by nBu₂Sn(OAc)₂ (2 drops) and the solution stirred at 20 °C for 24 h. The solvent was evaporated and the residue purified by chromatography, eluting with 20% EtOAc/DCM, to give 73 (75 mg, 91%) as a tan gum, 'H NMR δ 9.49 (s, 1 H, indole-NH), 8.19 (s, 1 H, OCONH), 7.92 (d, J= 8.5 Hz, 1 H, H 6), 7.80-7.82 (m, 1 H, H 5"), 7.78 (d, J= 8.3 Hz, 1 H, H 9), 7.71 (d, J= 1.8 Hz, 1 H, H 3"), 7.56 (ddd, J= 8.3, 7.1, 0.8 Hz, 1 H, H 8), 7.49-7.54 (m, 1 H, H 6"), 7.45 (ddd, J= 8.5, 7.1, 0.8 Hz, 1 H, H 7), 7.27 (br s, 1 H, H 4), 7.00 (d, J= 2.3 Hz, 1 H, H 3'), 6.87 (s, 1 H, H 4'), 5.39 (s, 2 H, CH₂O), 4.79 (dd, J= 10.7, 1.7 Hz, 1 H, H 2), 4.66 (dd, J= 10.7, 8.7 Hz, 1 H, H 2), 4.23 (dd, J= 4.6, 4.4 Hz, 2 H, CH₂O), 4.15-4.20 (m, 1 H, H 1), 4.08 (s, 3 H, OCH₃), 3.94-3.98 (m, 4 H, OCH₃, CH₂C1), 3.91 (s, 3 H, OCH₃), 3.80 (dd, J= 4.6, 4.4 Hz, 2 H, CH₂O), 3.47 (d, J= 10.9 Hz, 1 H, CH₂C1), 3.44 (s, 3 H, OCH₃); ¹³C NMR δ 160.3 (CO), 156.5 (C 2"), 154.0 (OCONH), 150.2 (C 5'), 148.5 (C 4"), 141.7 (C 3a), 140.6 (C 6'), 138.9 (C 7'), 133.9 (C 5), 132.4 (C 1"), 129.7 (C 2'), 129.6 (C 9a), 128.7 (C 6"), 127.5 (C 8), 125.6 (C 7a'), 125.0 (C 7), 123.6 (C 3a'), 123.1 (C 9), 122.5 (C 6, C 9b), 121.8 (C 5a), 116.0 (C 5"), 112.7 (C 4), 106.5 (C 3'), 106.3 (C 3"), 97.7 (C 4'), 70.7 (CH₂O), 68.5

(CH₂O), 61.9 (CH₂O), 61.5 (OCH₃), 61.1 (OCH₃), 59.3 (OCH₃), 56.3 (OCH₃), 54.9 (C 2), 45.9 (CH₂C1), 43.1 (C 1); MS (FAB⁺) m/z 721 (MH⁺, 1.5%), 719 (MH\ 3.5); HRMS (FAB⁺) calc. for C₃₆H₃₆ ³⁷C1N₄O₁₀ (MH⁺) m/z 721.2091, found 721.2131; calc. for C₃₆H₃₆ ³⁵C1N₄O₁₀ (MH⁺) m/z 719.2120, found 719.2133; Anal. (C₃₆H₃₅C1N₄O₁₀) C, H, N.

Example 4C. Preparation of l-[2-(3-hydroxypropoxy)-4-nitrophenyl]ethyl 4-[bis(2- chloroethyl)amino]phenylcarbamate (78).

Methyl 4-nitro-2-[3-(tetrahydro-2H-pyran-2-yloxy)propoxy]benzoate (74). A mixture of methyl 4-nitrosalicylate (66) (2.3 g, 11.7 mmol) and K₂CO₃ (2.42 g, 17.5 mmol) in DMF (25 mL) was stirred at 20 °C for 20 min. A solution of 3-iodopropyl tetrahydropyranyl ether (4.7 g, 17.5 mmol) in DMF (5 mL) was added and the mixture stirred at 100 °C for 2 h. The mixture was poured into water, extracted with EtOAc (3 x 100 mL), the combined organic extracts washed with water (2 50 mL), brine (50 mL), dried and the solvent evaporated. The residue was purified by chromatography, eluting with 20% EtOAc/light petroleum, to give 74 (3.66 g, 92 %) as a colourless oil, 'H NMR δ 7.89 (d, J= 8.5 Hz, 1 H, H 6), 7.80-7.84 (m, 2 H, H 3, H 5), 4.60-4.62 (m, 1 H, OCHO), 4.27 (t, J= 6.2 Hz, 2 H, CH₂O), 3.95-4.00 (m, 1 H CH₂O), 3.94 (s, 3 H, OCH₃), 3.79-3.86 (m, 1 H, CH₂O), 3.59- 3.66 (m, 1 H, CH₂O), 3.47-3.52 (m, 1 H, CH₂O), 2.13-2.17 (m, 2 H, CH₂), 1.78-1.84 (m, 1 H, CH₂), 1.68-1.75 (m, 1 H, CH₂), 1.47-1.62 (m, 4 H, 2 CH₂); ^,3C NMR δ 164.5, 158.6, 150.7, 132.0, 126.2, 114.8, 107.9, 99.0, 66.5, 63.4, 62.4, 52.5, 30.6, 29.3, 25.4, 19.6; MS m/z 339 (M⁺, 2%), 322 (12), 239 (20), 222(40), 85 (100); HRMS calc. for C₁₆H₂₁NO₇ (M⁺) m/z 339.1318, found 339.1317.

{4-Nitro-2-[3-(tetrahydro-2H-pyran-2-yloxy)propoxy]phenyl}methanol (75). DIBALH (1 M in DCM, 34 mL, 34 mmol) was added dropwise to a solution of 74 (3.46 g, 10.2 mmol) in THF (100 mL) at 5 °C and the solution stirred at 5 °C for 1 h. The solution was poured into a solution of sodium potassium tartrate (1 M, 100 mL) and stirred for 30 min. The mixture was extracted with EtOAc (3 x 100 mL), the combined organic fraction washed with water (100 mL), brine (50 mL), dried, and the solvent evaporated. The residue was purified by chromatography, eluting with 50%EtO Ac/light petroleum, to give 75 (3.11 g, 98 %) as a pale yellow solid, mp (EtOAc/light petroleum) 64-65.5 °C; 'H NMR δ 7.84 (dd, J= 8.2, 2.1 Hz, 1 H, H 5), 7.72 (d, J= 2.1 Hz, 1 H, H 3), 7.50 (d, J= 8.2 Hz, 1 H, H 6), 4.74 (dd, J= 14.8, 4.2 Hz, 2 H, CH₂O), 4.58-4.61 (m, 1 H, OCHO), 4.24 (t, J= 6.1 Hz, 2 H, CH₂O), 3.96 (dt, J= 10.0, 5.8 Hz, 1 H, CH₂O), 3.80-3.86 (m, 1 H, CH₂O), 3.62 (dt, 10.0, 5.8 Hz, 1 H, CH₂O), 3.46-3.51 (m, 1 H, CH₂), 2.30 (br s, 1 H, OH), 2.08-2.11 (m, 2 H, CH₂), 1.79-1.85 (m, 1 H, CH₂), 1.69-1.77 (m, 1 H, CH₂), 1.48-1.62 (m, 4 H, 2 CH₂); ¹³C NMR δ 156.5, 148.2, 136.8, 128.1, 115.9, 105.8, 99.3, 65.9, 63.9, 62.8, 60.8, 30.6, 29.3, 25.3, 19.7; MS (Cl, NH₃) m/z 312 (MH⁺, 0.5%), 294 (1), 245 (15), 227(30), 85 (100); HRMS (Cl, NH₃) calc. for C₁₅H₂₂NO₆ (MH⁺) m/z 312.1447, found 312.1438. Anal. (C₁₅H₂₁NO₆) C, H, N.

4-Nitro-2-[3-(tetrahydro-2H-pyran-2-yloxy)propoxy]benzyl 4-[bis(2- hydroxyethyl)amino]phenylcarbamate (76). Pyridine (135 μL, 1.67 mmol) was added dropwise to a strrred solution of alcohol 75 (521 mg, 1.67 mmol) and triphosgene (174 mg, 0.59 mmol) in THF (20 mL) at 5 °C and the suspension stirred at 5 °C for 1 h. A solution of N'N¹-bis(2-hydroxyethyl)-l,4-benzenediamine 57 [prepared by catalytic hydrogenation of NN-bis-(2-hydroxyethyl) 4-nitroaniline (360 mg, 1.84 mmol) with Pd/C under H₂ (60 psi) in EtOH] in THF (10 mL) and DMF (10 mL) was added and the mixture stirred at 20 °C for 16 h. The solvent was evaporated and the residue partitioned between EtOAc/water (100 mL). The aqueous fraction was extracted with EtOAc (2 50 mL) and the combined organic fraction washed with brine (50 mL), dried and the solvent evaporated. The residue was purified by chromatography, eluting with 80-100% EtOAc/light petroleum to give 76 (220 mg, 25 %) as a colourless oil, Η ΝMR [(CD₃)₂SO] δ 9.42 (s, 1 H, OCOΝH), 7.88 (dd, J= 8.3, 2.0 Hz, 1 H, H 5'), 7.79 (d, J= 2.0 Hz, 1 H, H 3'), 7.61 (br d, J= 8.3 Hz, 1 H, H 6'), 7.72 (br d, J= 9.1 Hz, 2 H, H 2, H 6), 6.61 d, J- 9.1 Hz, 2 H, H 3, H 5), 5.19 (s, 2 H, CH₂O), 4.73 (t, J= 5.4 Hz, 1 H, CH₂O), 4.54-4.58 (m, 1 H, OCHO), 4.23 (t, J= 6.1 Hz, 2 H, CH₂O), 3.80 (dt, J= 9.9, 6.4 Hz, 1 H, CH₂O), 3.67-3.71 (m, 1 H, CH₂O), 3.55 (t, J= 5.4 Hz, 1 H, CH₂O), 3.50 (t, J= 6.0 Hz, 4 H, 2 CH₂O), 3.32-3.35 (m, 4 H, 2 x CH₂Ν), 1.99- 2.06 (m, 2 H, CH₂), 1.67-1.73 (m, 1 H, CH₂), 1.56-1.62 (m, 1 H, CH₂), 1.40-1.49 (m, 4 H, 2 x CH₂); ¹³C NMR [(CD₃)₂SO] δ 156.2, 153.2, 148.1, 144.1, 132.9, 128.6, 127.4, 120.2 (2), 115.4, 111.4 (2), 106.0, 98.0, 65.7, 63.0, 61.3, 60.1, 58.1 (2), 53.4 (2), 30.2, 28.8, 25.0, 19.1; MS (FAB⁺) m/z 533 (M⁺, 20 %); HRMS (FAB⁺) calc. for C₂₆H₃₅N₃O₉ (M⁺) m/z 533.2373, found 533.2365.

2-(3-Hydroxypropoxy)-4-nitrobenzyl 4- [bis(2-chloroethyl)amino] phenylcarbamate (78). Methanesulphonyl chloride (85 μL, 1.1 mmol) was added dropwise to a stirred solution of 76 (195 mg, 0.36 mmol) in pyridine (10 mL) at 20 °C and the solution stirred for 1 h. The solvent was evaporated and the residue partitioned between DCM/water (100 mL). The aqueous fraction was extracted with DCM (2 x 50 mL) and the combined organic fraction washed with brine (50 mL), dried and the solvent evaporated. The residue was dissolved in DMF (10 mL), LiCl (93 mg, 2.2 mmol) added, and the mixture stirred at 80 °C for 3 h. The solvent was evaporated and the residue partitioned between EtOAc (100 mL) and water (100 mL). The aqueous fraction was extracted with EtOAc (2 x 50 mL). The combined organic fraction was washed with brine (50 mL), dried, and the solvent evaporated. The residue was purified by chromatography, eluting with 25% EtOAc/light petroleum, to give (i) 4-nitro-2-[3-(tetrahydro-2H-pyran-2-yloxy)propoxy]benzyl 4-[bis(2- chloroethyl)amino]phenylcarbamate (77) (46 mg, 22 %) as a colourless oil, 'H NMR δ 7.82 (dd, J= 8.3, 2.1 Hz, 1 H, H 5'), 7.73 (d, J= 2.1 Hz, 1 H, H 3'), 7. 50 (br d, J= 8.3 Hz, 1 H, H 6'), 7.26-7.29 (m, 3 H, OCONH, H 2, H 6), 6.65 (ddd, J= 9.1, 3.4, 1.9 Hz, 2 H, H 3, H 5), 5.25 (s, 2 H, CH₂O), 4.67 (br s, 1 H, OCHO), 4.20-4.27 (m, 2 H, CH₂O), 4.01 (dt, J = 9.7, 6.1 Hz, 1 H, CH₂O), 3.65-3.75 (m, 6 H, CH₂O, 2 x CH₂N), 3.58-3.63 (m, 4 H, 2 x

CH₂C1), 3.44-3.50 (m, 1 H, CH₂O), 2.1 1-2.15 (m, 2 H, CH₂), 1.66-1.72 (m, 1 H, CH₂), 1.55- 1.62 (m, 1 H, CH₂), 1.40-1.50 (m, 4 H, 2 x CH₂); ¹³C NMR δ 157.2, 153.6, 148.8, 142.6, 132.0, 129.8, 128.7, 121.3 (2), 115.5, 112.8 (2), 105.9, 98.4, 65.3, 63.0, 61.7 (2), 53.7 (2), 40.5 (2), 30.5, 29.3, 25.4, 19.0; MS (FAB⁺) m/z 569 (M⁺, 3%); HRMS (FAB⁺) calc for C₂₆H₃₃ ³⁵Cl₂N₃O₇ (M⁺) m/z 569.1696, found 569.1689; calc. for C₂₆H₃₃ ³⁵Cl³⁷ClN₃O₇ (M⁺) m/z 571.1666, found 569.1680; calc. for C₂₆H₃₃ ³⁷Cl₂N₃O₇ (M⁺) m/z 573.1637, found 569.1654.

Further elution gave 78 (99 mg, 57 %) as a white powder, mp (DCM/pet. ether) 104-105 °C; 'H δ 7.84 (dd, J= 8.3, 2.0 Hz, 1 H, H 5'), 7.74 (d, J= 2.0 Hz, 1 H, H 3'), 7.51 (br d, J= 8.3 Hz, 1 H, H 6'), 7.24 (br d, J = 9.0 Hz, 2 H, H 2, H 6), 6.87 (br s, 1 H, OCONH), 6.64 (d, J= 9.0 Hz, 2 H, H 3, H 5), 5.27 (s, 2 H, CH₂O), 4.27 (t, J= 5.8 Hz, 2 H, CH₂O), 3.89 (t, J= 5.7 Hz, 2 H, CH₂O), 3.67-3.72 (m, 4 H, 2 x CH₂N), 3.58-3.64 (m, 4 H, 2 x CH₂C1), 2.08- 2.12 (m, 2 H, CH₂); ¹³C NMR δ 156.8, 153.4, 148.7, 145.6, 132.0, 129.4, 128.2, 123.4 (2), 115.6, 112.7 (2), 106.1, 66.6, 61.5, 59.9, 53.6 (2), 40.5 (2), 31.6; Anal. (C₂₁H₂₅Cl₂N₃O₆) C, H, N, Cl.

Example 4D. Preparation of 2-(3-hydroxypropoxy)-4-nitrobenzyl 3-(chloromethyl)-l- [(5,6,7-trimethoxy-lH-indol-2-yl)carbonyl]-2,3-dihydro-lH-indol-6-ylcarbamate (80).

Pyridine (35 μL, 0.44 mmol) was added dropwise to a stirred solution of alcohol 75 (45 mg, 0.25 mmol) and triphosgene (45 mg, 0.15 mmol) in THF (10 mL) at 5 °C and the suspension stirred at 5 °C for 1 h. A solution of 3-(chloromethyl)-l-[(5,6,7-trimethoxy-lH- indol-2-yl)carbonyl]-2,3-dihydro-lH-indol-6-ylamine (33) [M. Tercel and W. A. Denny. J. Chem. Soc. Perkin Trans. 1, 1998, 509] (199 mg, 0.48 mmol) in TΗF (10 mL) was added and the mixture stirred at 20 °C for 16 h. The suspension was filtered and the solvent evaporated. The residue was purified by chromatography, eluting with 40% EtOAc/DCM, to give (i) 4-nitro-2-[3-(tetrahydro-2H-pyran-2-yloxy)propoxy]benzyl 3-(chloromethyl)-l- [(5,6,7-trimethoxy-lH-indol-2-yl)carbonyl]-2,3-dihydro-lH-indol-6-ylcarbamate 79 (116 mg, 35%) as an oil, Η NMR δ 9.54 (s, 1 H, NH), 8.24 (s, 1 H, H 7), 7.84 (s, 1 H, H 4), 7.77 (dd, J= 8.3, 2.0 Hz, 1 H, H 5"), 7.71 d, J= 2.0 Hz, 1 H, H 3"), 7.52 (br s, 1 H, OCONH), 7.48 (d, J= 8.3 Hz, 1 H, H 6"), 7.22 (d, J= 8.3 Hz, 1 H, H 4), 6.93 (d, J= 2.2 Hz, 1 H, H 3'), 6.85 (s, 1 H, H 4'), 5.27 (s, 2 H, CH₂O), 4.69 (br s, 1 H, OCHO), 4.62 (dd, J= 10.6, 9.4 Hz, 1 H, H 2), 4.45 (dd, J- 10.6, 3.8 Hz, 1 H, H 2), 4.20-4.24 (m, 2 H, CH₂O), 4.08 (s, 3 H, OCH₃), 3.94-3.98 (m, 1 H, CH₂O), 3.93 (s, 3 H, OCH₃), 3.91 (s, 3 H, OCH₃), 3.71-3.82 (m, 3 H, H 3, CH₂O, CH₂C1), 3.49-3.61 (m, 3 H, CH₂C1, CH-O), 2.10-2.15 (m, 2 H, CH₂), 1.65- 1.78 (m, 2 H, CH₂), 1.45-1.60 (m, 4 H, 2 x CH₂); ¹³C NMR δ 160.3, 157.2, 153.3, 150.2, 148.8, 144.1, 140.5, 138.9, 138.8, 131.8, 129.6, 129.5, 125.9, 125.5, 124.5, 123.6, 115.5, 114.6, 108.7, 107.9, 105.9, 98.4, 97.6, 67.6, 65.4, 63.0, 61.8, 61.4, 61.1, 56.2, 54.7, 46.9, 43.2, 30.6, 29.2, 25.4, 19.0; MS (FAB⁺) m/z 752 (M⁺, 8%), 669 (20), 234 (30); HRMS (FAB⁺) calc. for C₃₇H₄₁ ³⁵ClN₄O_u (M⁺) m/z 752.2460, found 752.2455; calc. for C₃₇H₄₁ ⁷ClN₄O_π (M⁺) m/z 754.2431, found 754.2424.

Further elution gave 80 (44 mg, 15%) as a tan solid, mp (EtOAc/light petroleum) 166-168 °C; 'H NMR δ 9.47 (s, 1 H, indole-NH), 8.24 (d, J= 1.8 Hz, 1 H, H 7), 7.79 (dd, J= 8.3, 2.1 Hz, 1 H, H 5"), 7.71 (d, J= 2.1 Hz, 1 H, H 3"), 7.48 (d, J= 8.3 Hz, 1 H, H 6"), 7.42 (br s, 1 H, OCONH), 7.33 (s, 1 H, H 5), 7.21 (d, J= 8.2 Hz, 1 H, H 4), 6.93 (d, J= 2.3 Hz, 1 H, H 3'), 6.85 (s, 1 H, H 4'), 5.29 (s, 2 H, CH₂O), 4.62 (dd, J= 10.8, 9.8 Hz, 1 H, H 2), 4.46 (dd, J= 10.8, 4.5 Hz, 1 H, H 2), 4.25 (t, J= 5.8 Hz, 2 H, CH₂O), 4.07 (s, 3 H, OCH₃), 3.94 (s, 3 H, OCH₃), 3.88-3.93 (m, 5 H, OCH₃, CH₂O), 3.79-3.85 (m, 2 H, H 3, CH₂C1), 3.55 (dd, J= 12.1, 10.3 Hz, 1 H, CH₂C1), 2.28 (br t, J= 4.9 Hz, 1 H, OH), 2.09-2.14 (m, 2 H, CH₂); ¹³C NMR δ 160.5, 156.8, 153.1, 150.1, 148.5, 144.0, 140.5, 138.7, 138.6, 131.7, 130.8, 129.5, 129.3, 126.0, 125.8, 124.5, 123.5, 115.5, 114.6, 108.5, 106.7, 106.0, 66.0, 61.7, 61.5, 61.1, 59.4, 56.1, 54.7, 46.9, 43.2, 31.6; MS (FAB⁺) m/z 671 (MH⁺, 1%), 669 (MH⁺, 3%), 391 (15), 149 (100); HRMS (FAB⁺) calc. for C₃₂H₃₄ ³⁵C1N₄O₁₀ (MH⁺) m/z 669.1964, found 669.1921; calc. for C₃₂H₃₄ ³⁷C1N₄O₁₀ (MH⁺) m/z 669.1934, found 671.1875; Anal. (C₃₂H₃₃C1N₄O₁₀. */2H₂O) C, H, N.

Compound 80 was also prepared by treating a solution of 79 (96 mg, 0.13 mmol) in MeOH (5 mL) with 0.1 M HCI (2 mL) and stirring at 20 °C for 16 h. The solvent was evaporated and the residue partitioned between DCM (50 mL) and water (50 mL). The organic fraction was washed with water (10 mL), brine (10 mL), dried, and the solvent evaporated. The residue was purified by chromatography, eluting with 40% EtOAc/DCM, to give 80 (69 mg, 79%) as a tan solid, spectroscopically identical with the sample prepared above.

Example 4E. Preparation of 2-(3-hydroxypropoxy)-4-nitrobenzyl l-(chloromethyl)-3- [(5,6,7-trimethoxy-lH-indol-2-yl)carbonyl]-2,3-dihydro-lH-benzo[e]indol-5- ylcarbamate (84).

Methyl 2-(3-{[tert-butyl(dimethyl)silyl]oxy}propoxy)-4-nitrobenzoate (81). A mixture of methyl 2-hydroxy-4-nitrobenzoate (66) (1.82 g, 9.23 mmol) and K₂CO₃ (1.91 g, 13.85 mmol) in DMF (30 mL) was stirred at 20 °C for 30 min. A solution of 3-bromopropyl tert- butyl(dimethyl)silyl ether (3.50 g, 13.85 mmol) in DMF (10 mL) was added and the mixture stirred at 100 °C for 3 h. The mixture was poured into water (300 mL), extracted with EtOAc (3 x 100 mL) and the combined organic extract washed with water (2 x 100 mL), brine (50 mL), dried and the solvent evaporated. The residue was purified by chromatography, eluting with 10% EtOAc/light petroleum, to give 81 (3.19 g, 93%) as a pale yellow solid, mp (EtOAc) 36.5-37 °C; 'H NMR δ 7.88 (d, J= 8.9 Hz, 1 H, H 6), 7.80- 7.84 (m, 2 H, H 3, H 5), 4.24 (t, J= 6.0 Hz, 2 H, CH-O), 3.92 (s, 3 H, OCH₃), 3.85 (t, J= 5.9 Hz, 2 H, CH₂O), 2.04-2.09 (m, 2 H, CH₂), 0.88 (s, 9 H, OSi(CH₃)₃), 0.04 (s, 6 H, OSi(CH₃)₂); ¹³C NMR δ 165.4 (CO₂), 158.7 (C 2), 150.7 (C 4), 132.0 (C 6), 126.1 (C 1), 114.8 (C 5), 107.7 (C 3), 64.0 (CH₂O), 59.0 (CH₂O), 52.5 (OCH₃), 32.0 (CH₂), 25.9 (SiC(CH₃)₃), 18.3 (SiC(CH₃)₃), -5.5 (Si(CH₃)₂); Anal. (C₁₇H₂₇NO₆Si) C, H, N.

[2-(3-{[tert-Butyl(dimethyI)silyl]oxy}propoxy)-4-nitrophenyl]methanol (82). DIBALH

(1 M in DCM, 16.5 mL, 16.5 mmol) was added to a stirred solution of ester 81 (1.85 g, 5.0 mmol) in THF (100 mL) at 5 °C and the solution stirred at 5 °C for 1 h. The solution was poured into a solution of potassium sodium tartrate (1 M, 100 mL) and the mixture stirred vigorously for 20 min. The mixture was extracted with EtOAc (3 x 100 mL), the combined organic fraction washed with water (100 mL), brine (50 mL), dried, and the solvent evaporated. The residue was purified by chromatography, eluting with 20% EtOAc/light petroleum, to give 82 (1.64 g, 94%) as a pale yellow solid, mp (EtOAc/light petroleum) 48- 49 °C; 'H NMR δ 7.84 (dd, J= 8.3, 2.1 Hz, 1 H, H 5), 7.71 (d, J= 2.1 Hz, 1 H, H 3), 7.51 (d, J= 8.3 Hz, 1 H, H 6), 4.76 (d, J= 6.3 Hz, 2 H, CH₂O), 4.21 (t, J= 6.1 Hz, 2 H, CH₂O), 3.82 (t, J= 5.9 Hz, 2 H, CH₂OSi), 2.40 (t, J= 6.3 Hz, 1 H, OH), 2.02-2.08 (m, 2 H, CH₂), 0.89 (s, 9 H, OSiC(CH₃)₃), 0.06 (s, 6 H, OSi(CH₃)₂); ¹³C NMR δ 156.5 (C 2), 148.2 (C 4), 136.7 (C 1), 127.8 (C 6), 1 15.9 (C 5), 105.8 (C 3), 65.5 (CH₂O), 60.8 (CH₂O), 59.3 (CH₂O), 32.0 (CH₂), 25.9 (OSiC(CH₃)₃), 18.3 (OSiC(CH₃)₃), -5.4 (OSi(CH₃)₂; Anal. (C₁₆H₂₇NO₅Si) C, H, N.

2-(3-{[tert-Butyl(dimethyl)silyl]oxy}propoxy)-4-nitrobenzyl l-(chloromethyI)-3-[(5,6,7- trimethoxy-lH-indol-2-yl)carbonyl]-2,3-dihydro-lH-benzo[e]indol-5-ylcarbamate

(83). A solution of triphosgene (15 mg, 51 μmol) in DCM (2 mL) was added dropwise to a stiπed solution of amine 1 [G. J. Atwell, W. R. Wilson, W. A. Denny, Bioorg. Med. Chem. Lett., 1997, 7, 1483] (60 mg, 129 μmol) and Et₃N (40 μL, 289 μmol) in DCM (10 mL) and stirred at 20 °C for 2 h. A solution of alcohol 82 (54 mg, 159 μmol) in DCM (2 mL) was added, followed by nBu₂Sn(OAc)₂ (2 drops) and the solution stirred at 20 °C for 24 h. The solvent was evaporated and the residue purified by chromatography, eluting with a gradient (0-10%) MeOH/EtO Ac, to give 83 (72 mg, 67%) as a yellow solid mp (MeOH) 149-151 °C; 'H NMR δ 9.42 (s, 1 H, indole-NH), 8.96 (s, 1 H, OCONH), 7.91 (d, J= 8.4 Hz, 1 H, H 6), 7.78-7.85 (m, 2 H, H 9, H 5"), 7.75 (d, J, 1.7 Hz, 1 H, H 3"), 7.53-7.59 (m, 2 H, H 8, H 6"), 7.47 (ddd, J= 8.4, 7.4, 0.8 Hz, 1 H, H 7), 7.08 (br s, 1 H, H 4), 7.02 (d, J= 2.2 Hz, 1 H, H 3'), 6.89 (s, 1 H, H 4'), 5.38 (s, 2 H, CH₂O), 4.82 (dd, J= 10.7, 1.7 Hz, 1 H, H 2), 4.69 (dd, J= 10.7, 8.7 Hz, 1 H, H 2), 4.21 (t, J= 6.0 Hz, 2 H, CH₂O), 4.17-4.20 (m, 1 H, CH₂C1), 4.09 (s, 3 H, OCH₃), 3.99 (dd, J= 11.3, 2.9 Hz, 1 H, H 1), 3.95 (s, 3 H, OCH₃), 3.92 (s, 3 H, OCH₃), 3.83 (t, J= 5.9 Hz, 2 H, CH₂O), 3.49 (t, J= 11.0 Hz, 1 H, CH₂C1), 2.02-2.08 (m, 2 H, CH₂), 0.88 (s, 9 H, OSiC(CH₃)₃), 0.04 (s, 6 H, OSi(CH₃)₂; MS (FAB⁺) m/z 833 (MH⁺, 25%), 835 (MH⁺, 12), 775 (5), 599 (5); HRMS (FAB⁺) calc. for C₄₂H₅₀ ³⁵ClN₄O₁₀Si (MH⁺) m/z 833.2985, found 833.3008; calc. for C₄₂H₅₀ ³⁷ClN₄O₁₀Si (MH⁺) m/z 835.2955, found 835.2982; Anal. (C₄₂H₄₉ClN₄O₁₀Si) C, H, N.

2-(3-Hydroxypropoxy)-4-nitrobenzyl l-(chloromethyl)-3-[(5,6,7-trimethoxy-l/7-indol- 2-yl)carbonyl]-2,3-dihydro-lH-benzo[e]indol-5-ylcarbamate (84). 1 M HCI (0.2 mL, 200 μmol) was added to a stiπed solution of silyl ether 83 (64 mg, 77 μmol) in MeOH (5 mL) and the solution stiπed at 20 °C for 30 min. The solvent was evaporated and the residue dissolved in EtOAc (50 mL), washed with water (2 50 mL), brine (25 mL), dried and the solvent evaporated. The residue was purified by chromatography, eluting with a gradient (50-100%) of EtOAc/light petroleum, to give 84 (52 mg, 94%) as a tan solid, mp (EtOAc) 122-126 °C; 'H NMR δ 9.51 (s, 1 H, indole-NH), 8.90 (s, 1 H, OCONH), 7.92 (d, J= 8.5 Hz, 1 H, H 6), 7.80 (d, J= 8.2 Hz, 1 H, H 5"), 7.77 (d, J= 8.3 Hz, 1 H, H 9), 7.73 (d, J, 1.8 Hz, 1 H, H 3"), 7.50-7.57 (m, 2 H, H 8, H 6"), 7.40-7.46 (m, 2 H, H 4, H 7), 6.99 (d, J= 2.2 Hz, 1 H, H 3'), 6.87 (s, 1 H, H 4'), 5.37 (d, J= 13.1 Hz, 1 H, CH₂O), 5.32 (d, J = 13.1 Hz, 1 H, CH₂O), 4.77 (dd, J= 10.8, 1.6 Hz, 1 H, H 2), 4.64 (dd, J= 10.8, 8.6 Hz, 1 H, H 2), 4.27 (t, J= 5.7 Hz, 2 H, CH₂O), 4.1 1-4.18 (m, 1 H, CH₂C1), 4.09 (s, 3 H, OCH₃), 3.96 (s, 3 H, OCH₃), 3.91-3.95 (m, 3 H, H 1, CH₂O), 3.90 (s, 3 H, OCH₃), 3.44 (t, J= 10.9 Hz, 1 H, CH₂C1), 2.75 (br s, 1 H, OH), 2.12-2.18 (m, 2 H, CH₂); ¹³C NMR δ 160.4 (CO), 157.2 (C 2"), 153.8 (OCONH), 150.2 (C 5'), 148.9 (C 4"), 141.6 (C 3a), 140.6 (C 6'), 138.9 (C 7'), 134.0 (C 5), 131.6 (C 1"), 130.1 (C 6"), 129.7 (C 2'), 129.6 (C 9a), 127.5 (C 8), 125.7 (C 7a'), 125.0 (C 7), 123.6 (C 3a'), 123.1 (C 9), 122.4 (C 6, C 9b), 121.6 (C 5a), 115.7 (C 5"), 112.2 (C 4), 106.6 (C 3'), 106.1 (C 3"), 97.7 (C 4'), 66.8 (CH₂O), 62.2 (CH₂O), 61.5 (OCH₃), 61.1 (OCH₃), 60.1 (CH₂O), 56.3 (OCH₃), 55.0 (C 2), 45.8 (CH₂C1), 43.4 (C 1), 31.6 (CH₂); MS (FAB⁺) m/z 111 (MH⁺, 2%), 719 (MH\ 4); HRMS (FAB⁺) calc. for C₃₆H₃₅ ³⁵C1N₄O₁₀ (MH⁺) m/z 719.2120, found 719.2107; calc. for C₃₆H₃₅ ³⁷C1N₄O₁₀ (MH⁺) m/z 721.2091, found 721.2093; Anal. (C₃₆H₃₅C1N₄O₁₀) C, H, N.

Example 4F. Preparation of 2-(3-hydroxypropoxy)-4-nitrobenzyl doxorubicin carbamate (87). 4-Nitrophenyl 4-nitro-2- [3-(tetrahydro-2H-pyran-2-yloxy)propoxy] benzyl carbonate

(85). A solution of 4-nitrophenylchloroformate (0.43 g, 2.1 mmol) in THF (10 mL) was added dropwise to a stirred solution of alcohol 75 (0.44 g, 1.4 mmol) and DIEA (0.49 mL, 2.8 mmol) in THF (40 mL) and the mixture stirred at 20 °C for 48 h. The solution was evaporated and the residue partitioned between EtOAc (100 mL) and water (100 mL). The organic fraction was washed with water (3 x 50 mL), brine (50 mL), dried, and the solvent evaporated. The residue was purified by chromatography, eluting with a gradient (10-50%) EtOAc/light petroleum, to give (i) starting material (176 mg, 40%); and (ii) 85 (0.38 g, 56%) as a pale yellow oil, 'H NMR δ 8.30 (ddd, J= 9.2, 3.1, 2.1 Hz, 2 H, H 3, H 5), 7.87 (dd, J= 8.4, 2.1 Hz, 1 H, H 5'), 7.79 (d, J= 2.1 Hz, 1 H, H 3'), 7.57 (d, J= 8.4 Hz, 1 H, H 6'), 7.41 (ddd, J= 9.2, 3.1, 2.1 Hz, 2 H, H 2, H 6), 5.42 (s, 2 H, CH₂O), 4.58-4.61 (m, 1 H, OCHO), 4.28 (t, J= 6.3 Hz, 2 H, CH₂O), 3.96 (dt, J= 10.0, 6.0 Hz, 1 H, CH₂O), 3.78-3.83 (m, 1 H, CH₂O), 3.59 (dt, J= 10.0, 6.0 Hz, 1 H, CH₂O), 3.45-3.52 (m, 1 H, CH₂O), 2.13- 2.18 (m, 2 H, CH₂O), 1.79-1.86 (m, 1 H, CH₂), 1.67-1.76 (m, 1 H, CH₂), 1.48-1.60 (m, 4 H, 2 x CH₂); ¹³C NMR δ 157.0 (C 1), 155.4 (C 2'), 153.4 (OCONH), 149.2 (C 4'), 145.5 (C 4), 129.9 (C 1), 129.2 (C 6'), 125.3 (C 3, C 5), 121.7 (C 2, C 6), 115.6 (C 5'), 106.3 (C 6'), 99.1 (OCO), 66.1 (CH₂O), 65.3 (CH₂O), 63.5 (CH₂O), 60.4 (CH₂O), 30.6 (CH₂), 29.4 (CH₂), 25.4 (CH₂), 19.7 (CH₂); MS m/z 416 (M⁺, 2%), 459 (5), 392 (2), 210(30), 85 (100); HRMS calc. for C₂₂H₂₄N₂O₁₀ (M⁺) m/z 476.1431, found 476.1425.

2-(3-Hydroxypropoxy)-4-nitrobenzyl 4-nitrophenyl carbonate (86). A solution of ether 85 (207 mg, 0.47 mmol) in THF (20 mL) and 1 M HCI (5 mL) was stirred at 20 °C for 16 h. The solvent was evaporated and the residue partitioned between EtOAc (50 mL) and water (50 mL). The organic fraction was dried, the solvent evaporated, and the residue purified by chromatography, eluting with 50% EtOAc/light petroleum, to give 86 (125 mg, 68%) as a white solid, mp (EtOAc/light petroleum) 116-117 °C; Η NMR δ 8.29 (ddd, J = 9.1, 3.2, 2.1 Hz, 2 H, H 3, H 5), 7.88 (dd, J= 8.3, 2.1 Hz, 1 H, H 5'), 7.80 (d, J= 2.1 Hz, 1 H, H 3'), 7.58 (d, J= 8.3 Hz, 1 H, H 6'), 7.40 (ddd, J= 9.1, 3.2, 2.1 Hz, 2 H, H 2, H 6), 5.41 (s, 2 H, CH₂O), 4.30 (t, J= 6.0 Hz, 2 H, CH₂O), 3.90 (dt, J= 5.4, 4.6 Hz, 2 H, CH₂O), 2.10-2.15 (m, 2 H, CH₂), 1.65 (br s, 1 H, OH); ¹³C NMR δ 157.0 (C 2'), 155.3 (C 1), 152.3 (OCONH), 149.3 (C 4'), 145.5 (C 4), 129.8 (C 1 '), 129.6 (C 6'), 125.4 (C 2, C 6), 121.7 (C 3, C5), 115.8 (C 5'), 106.4 (C 3'), 66.2 (CH₂O), 65.3 (CH₂O), 59.5 (CH₂O), 31.7 (CH₂); Anal. (C₁₇H₁₆N₂O₉) C, H, N.

2-(3-Hydroxypropoxy)-4-nitrobenzyl doxorubicin carbamate (87). A solution of carbonate 86 (41 mg, 104 μmol) in DMF (2 mL) was added dropwise to a stirred solution of doxorubicin 13 (46 mg, 86 μmol) and Et₃N (15 μL, 104 μmol) in DMF (5 mL) at 20 °C and the solution stirred for 16 h. The solvent was evaporated and the residue purified by chromatography, eluting with a gradient (0-10%) of MeOH/DCM, to give 87 (69 mg, 84%) as a red solid, mp (DCM) 154-160 °C; Η NMR [(CD₃)₂SO] δ 14.00 (s, 1 H, 6-OH), 13.24 (s, 1 H, 11-OH), 7.85-7.89 (m, 2 H, H 1, H 3), 7.80 (dd, J= 8.3, 1.8 Hz, 1 H, H 5"), 7.71 (d, J= 1.8 Hz, 1 H, H 3"), 7.62 (dd, J= 6.6, 2.8 Hz, 1 H, H 2), 7.50 (d, J- 8.3 Hz, 1 H, H 6"), 7.07 (d, J= 8.0 Hz, 1 H, OCONH), 5.42 (s, 1 H, 9-OH), 5.14 (br s, 1 H, H 1 '), 5.05 (d, J = 18.4 Hz, 1 H, CH₂O), 4.99 (d, J= 18.4 Hz, 1 H, CH₂O), 4.92 (br s, 1 H, H 7), 4.85 (t, J = 6.0 Hz, 1 H, 14-OH), 4.74 (d, J= 5.8 Hz, 1 H, 4'-OH), 4.58 (ά, J= 6.0 Hz, 2 H, H 14), 4.55 (t, J= 5.3 Hz, 1 H, H 5'), 4.14-4.20 (m, 2 H, CH₂O), 3.97 (s, 3 H, 4-OCH₃), 3.69-3.76 (m, 1 H, H 3'), 3.54 (dt, J= 6.0, 5.7 Hz, 2 H, CH₂O), 3.48 (br s, 1 H, H 4'), 3.30 (br s, 1 H, OH), 2.98 (d, J= 18.2 Hz, 1 H, H 10), 2.90 (d, J= 18.2 Hz, 1 H, H 10), 2.22 (br d, J= 14.4 Hz, 1 H, H 8), 2.09 (dd, J= 14.4, 5.5 Hz, 1 H, H 8), 1.88-1.92 (m, 1 H, H 2'), 1.82-1.87 (m, 2 H, CH₂), 1.50 (dd, J= 12.4, 3.7 Hz, 1 H, H 2'), 1,13 (d, J= 6.4 Hz, 3 H, H 6'); ^,3C NMR [(CD₃)₂SO] δ 213.7 (C 13), 186.4 (C 5), 186.3 (C 12), 160.7 (C 4), 156.0 (C 2"), 155.9 (C 6), 154.9 (C 11), 154.4 (OCONH), 147.8 (C 4"), 136.1 (C 2), 135.4 (C 12a), 134.5 (C 6a), 134.0 (C 10a), 133.2 (C 1"), 127.8 (C 6"), 119.9 (C 4a), 119.6 (C 1), 118.9 (C 3), 115.3 (C 5"), 110.6 (C 5a), 110.5 (C 11a), 105.8 (C 3"), 100.2 (C 1 '), 74.8 (C 9), 69.8 (C 7), 67.9 (C 4'), 66.6 (C 5'), 65.6 (CH₂O), 63.6 (C 14), 59.8 (CH₂O), 57.0 (CH₂O), 56.5 (4-OCH₃), 47.2 (C 3'), 36.5 (C 8), 32.0 (C 10), 31.7 (CH₂), 29.7 (C 2'), 16.9 (C 6'); MS (FAB⁺) m/z 797 (MH⁺, 0.3%); HRMS (FAB⁺) calc. for C₃₈H₄₀N₂O₁₇ (MH⁺) m/z 797.2405, found 797.2953; Anal. (C₃₈H₄₀N₂O₁₇.¹/₂H₂O) C, H, N.

Example 4G. Preparation of 2-(3-hydroxypropoxy)-4-nitrobenzyl bis(3-{[(5-methyl-4- acridinyl)carbonyl]amino}propyl)carbamate (91).

4-Nitro-2-[3-(tetrahydro-2/7-pyran-2-yloxy)propoxy]benzyl bis{3- [(trifluoroacetyl)amino]propyl}carbamate (88). A solution of alcohol 75 (623 mg, 2.0 mmol) and DIEA (0.40 mL, 2.4 mmol) in DCM (8 mL) was added dropwise to a solution of triphosgene (208 mg, 0.70 mmol) in DCM (6 mL) over 30 minutes at 5 °C and stirred for 1 h. The reaction mixture was added dropwise to a suspension of bistrifluoroacetamide 47 (880 mg, 2.0 mmol) and DIEA (0.76 mL, 4.8 mmol) in DCM (8 mL) and the solution stirred at 20 °C for 16 h. The solvent was evaporated and the residue purified by chromatography, eluting with 50% EtO Ac/petroleum ether, to give 88 (804 mg, 61%) as a colorless oil, 'H NMR [(CD₃)₂SO] δ 7.85 (dd, J= 8.0, 2.0 Hz, 1 H, H 5'), 7.80 (br s, 1 H, CONH), 7.76 (d, J- 2.0 Hz, 1 H, H 3'), 7.44 (d, J= 8.0 Hz, 1 H, H 6'), 6.81 (br s, 1 H, CONH), 5.25 (s, 2 H, CH₂O), 4.58-4.61 (m, 1 H), 4.22-4.26 (m, 2 H), 3.91-3.98 (m, 1 H), 3.79-3.86 (m, 1 H), 3.56-3.63 (m, 1 H), 3.46-3.53 (m, 1 H), 3.28-3.40 (m, 8 H), 2.04-2.16 (m, 2 H), 1.72-1.87 (m, 6 H), 1.50-1.63 (m, 4 H); ¹³C NMR [(CD₃)₂SO] δ 157.0, 156.9, 148.9, 131.5, 129.4, 115.7, 105.3, 99.2, 65.9, 63.7, 62.6, 62.5, 44.3 (2), 37.4, 36.1, 30.7, 29.4, 28.1, 27.1, 25.3, 19.6, 2 CF₃CO not observed; HRMS (FAB⁺) calc. for C₂₆H₃₄F₆N₄O₉ (M⁺) m/z 660.2230; found 660.2234

4-Nitro-2-[3-(tetrahydro-2H-pyran-3-yloxy)propoxy]benzyl bis(3-{[(5-methyl-4- acridinyl)carbonyl]amino}propyl)carbamate (90). A solution of carbamate 88 (165 mg, 0.25 mmol), Cs₂CO₃ (1.0 g, 3.0 mmol) and water (1 mL) in methanol (4 mL) was stiπed at 20 °C for 8 h. The pH was adjusted to 10, water (50 mL) added, the solution was extracted with DCM (3 50 mL). The combined organic fraction was dried, and the solvent was evaporated to give crude 4-nitro-2-[3-(tetrahydro-2H-pyran-2-yloxy)propoxy]benzyl bis(3- aminopropyl)carbamate (89). 4-(lH-Imidazol-l-ylcarbonyl)-5-methylacridine (50) [S. A. Gamage, J. A. Spicer, G. J. Atwell, G. J. Finlay, B. C. Baguley, W. A. Denny, J. Med. Chem., 1999, 42, 2383-2393] (144 mg, 0.50 mmol) was added to a solution of carbamate (89) in TΗF (10 mL) at 5 °C and the reaction mixture was stiπed at 20 °C for 8 h. The solvent was evaporated, and the residue was purified by chromatography on alumina-90, eluting with l%MeOΗ/55%EtOAc/DCM, to give 90 (183 mg, 88%) as a yellow solid, mp (EtOAc/DCM) 80-81 °C; 'H NMR δ 11.90 (s, 1 H, NH), 11.83 (s, 1 H, NH), 8.88-8.92 (m, 2 H), 8.62-8.72 (m, 2 H), 8.02-8.05 (m, 2 H), 7.74-7.83 (m, 2 H), 7.50-7.63 (m, 4 H), 7.36- 7.45 (m, 2 H), 7.30 (ά, J= 2.0 Hz, 1 H, H 3'"), 7.02 (d, J= 8.4 Hz, 1 H, H 6'"), 6.90 (dd, J = 8.4, 2.0 Hz, 1 H, H 5"'), 5.01 (s, 2 H, CH₂O), 4.56 (s, 1 H), 4.00-3.50 (m, 14 H), 2.83 (s, 3 H, CH₃), 2.71 (s, 3 H, CH₃), 2.14-1.50 (m, 12 H); ¹³C NMR δ 166.1, 155.6, 155.5, 147.5 (2), 147.0 (2), 145.2 (2), 137.9 (2), 135.8, 135.4, 135.2 (2), 132.6 (2), 132.3 (2), 131.0 (2), 128.3, 128.0, 126.5, 126.4, 126.2, 126.1 (2), 125.7 (2), 125.3 (2), 114.9, 104.9, 99.1, 65.6, 63.6, 62.5, 61.6, 45.9, 45.1, 37.7, 37.1, 30.7, 29.3, 29.4, 28.6, 25.4, 19.7, 18.9, 18.8, 14.2; Anal. (C₅₂H₅₄N₆O₉.¹/₂H₂O) C, H, N.

2-(3-Hydroxypropoxy)-4-nitrobenzyl bis(3-{[(5-methyl-4- acridinyl)carbonyl]amino}propyl)carbamate dihydrochloride (91). A solution of ether 90 (51 mg, 56 μmol) and HCI (1 M, 1.5 mL) in MeOH (10 mL) was stirred at 20 °C for 4 hrs. The solvent was evaporated and the residue was recrystallized to give 91 (46 mg, 92%) as a yellow solid, mp (MeOH/EtOAc/light petroleum) 143-145°C; Η NMR [(CD₃)₂SO] δ 1 1.23 (s, 2 H, 2 x NH), 9.17 (s, 1 H), 9.11 (s, 1 H), 8.70 (br s, 2 H), 8.24 (br s, 2 H), 7.96 (br s, 2 H), 7.66 (br s, 4 H), 7.51 (br s, 2 H), 7.32 (d, J- 2.0 Hz, 1 H, H 3"), 7.02 (d, J= 8.4 Hz, 1 H, H 6"), 6.97 (dd, J= 8.4, 2.0 Hz, 1 H, H 5"), 4.80 (s, 2 H, CH₂O), 3.92-3.96 (m, 2 H), 3.50-3.53 (m, 10 H), 2.72 (s, 3 H, CH₃), 2.63 (s, 3 H, CH₃), 2.01-2.04 (m, 4 H, 2 CH₂), 1.75-1.82 (m, 2 H); HRMS (FAB⁺) calc. for (C₄₇H₄₆N₆O₈) (M⁺) m/z 823.3455, found 823.3467; Anal. (C₄₇H₄₆N₆O₈.2HC1.2^»/2H₂O) C, H, N.

Example 4H. Preparation of 4-nitro-2-[3-(phosphonooxy)propoxy]benzyl 1- (chloromethyl)-3-[(5,6,7-trimethoxy-lH-indol-2-yl)carbonyl]-2,3-dihydro-lH- benzo[e]indol-5-ylcarbamate (93). 2-(3-{[Di(tert-butoxy)phosphoryl]oxy}propoxy)-4-nitrobenzyl l-(chloromethyl)-3- [(5,6,7-trimethoxy-lH-indol-2-yl)carbonyl]-2,3-dihydro-lH-benzo[e]indol-5- ylcarbamate (92). Tetrazole (40 mg, 567 μmol) was added to a stirred solution of alcohol 84 (Example 4E) 136 mg, 189 μmol) and di-tert-butyl diethylphosphoramidite (68 μL, 227 mmol) in THF (10 mL) under N₂ and the solution stirred at 20 °C for 4 h. The solution was cooled to -40 °C and a dried (Na₂SO₄) solution of MCPBA (70 %, 65 mg, 265 μmol) in DCM (3 mL) added. The solution was stirred at -40 °C for 10 min and a solution of 10% NaHSO₄ (10 mL) added and the mixture stirred for 10 min. The mixture was extracted with diethyl ether (80 mL), the organic fraction washed with 10% aq. NaHSO₄ (10 mL), sat. aq. KHCO₃ (10 mL), dried, and the solvent evaporated. The residue was purified by chromatography, eluting with a gradient (10-50%) EtOAc/light petroleum, to give 92 (160 mg, 93%) as an oil, 'H NMR δ 9.42 (s, 1 H, indole-NH), 8.89 (s, 1 H, OCONH), 8.15 (d, J = 8.5 Hz, 1 H, H 6), 7.83 (dd, .7= 8.2, 2.1 Hz, 1 H, H 5"), 7.79 (s, 1 H, H 4), 7.75 (d, J= 8.2 Hz, 1 H, H 6"), 7.73 (d, J= 2.1 Hz, 1 H, H 3"), 7.60 (d, J= 8.3 Hz, 1 H, H 9), 7.53 (ddd, J = 8.3, 7.1, 0.8 Hz, 1 H, H 8), 7.39 (ddd, J= 8.5, 7.1, 0.8 Hz, 1 H, H 7), 7.01 (d, J= 2.1 Hz, 1 H, H 3'), 6.89 (s, 1 H, H 4'), 5.34 (s, 2 H, CH₂O), 4.81 (dd, J= 10.7, 1.8 Hz, 1 H, H 2), 4.64 (dd, J= 10.7, 8.6 Hz, 1 H, H 2), 4.35 (dt, J= 5.6, 5.5 Hz, 2 H, CH₂O), 4.29 (t, J= 5.6 Hz, 2 H, CH₂O), 4.15-4.20 (m, 1 H, H 1), 4.10 (s, 3 H, OCH₃), 3.98 (dd, J- 11.2, 2.9 Hz, 1 H, CH₂C1), 3.95(s, 3 H, OCH₃), 3.92 (s, 3 H, OCH₃), 3.45 (dd, J= 10.9, 10.8 Hz, 1 H, CH₂C1), 2.19-2.25 (m, 2 H, CH₂), 1.35 (2s, 18 H, 2 x OC(CH₃)₃); MS (FAB⁺) m/z 913 (MH⁺, 0.4%), 911 (MH⁺, 0.8); HRMS (FAB⁺) calc. for C₄₄H₅₃ ³⁵ClN₄O₁₃P (MH⁺) m/z 911.3035, found 911.3003; calc. for C₄₄H₅₃ ³⁷ClN₄O₁₃P (MH⁺) m/z 913.3006, found 913.3002. 4-Nitro-2-[3-(phosphonooxy)propoxy]benzyl l-(chloromethyI)-3-[(5,6,7-trimethoxy- lH-indol-2-yl)carbonyl]-2,3-dihydro-lH-benzo[e]indol-5-ylcarbamate (93).

Trifluoroacetic acid (130 μL, 1.64 μmol) was added to a stirred solution of ester 92 (150 mg, 165 μmol) in DCM (5 mL) and the solution stiπed at 20 °C for 1 h. The solvent was evaporated, and the residue azeotroped with benzene (3 1 mL) to give 93 (88 mg, 66%) as a gum, ^]H NMR δ 11.47 (s, 1 H, indole-NH), 9.94 (s, 1 H, OCONH), 8.57 (br s, 3 H, H 4, 2 OH), 8.1 1 (d, J= 8.5 Hz, 1 H, H 6), 7.98 (d, J= 8.3 Hz, 1 H, H 9), 7.91 (d, J= 8.3 Hz, 1 H, H 5"), 7.81 (d, J= 1.8 Hz, 1 H, H 3"), 7.69 (d, J= 8.3 Hz, 1 H, H 6"), 7.58 (ddd, J = 8.3, 7.2, 0.7 Hz, 1 H, H 8), 7.47 (ddd, J= 8.5, 7.2, 0.7 Hz, 1 H, H 7), 7.10 (d, J= 2.2 Hz, 1 H, H 3'), 6.97 (s, 1 H, H 4'), 5.29 (s, 2 H, CH₂O), 4.80 (dd, J= 10.8, 9.4 Hz, 1 H, H 2), 4.53 (dd, J= 10.8, 1.7 Hz, 1 H, H 2), 4.31 -4.37 (m, 1 H, H 1), 4.27 (t, J= 6.1 Hz, 2 H, CH₂O), 4.07 (dd, J= 11.2 Hz, 1 H, CH₂C1), 4.03 (dt, J= 7.1, 6.2 Hz, 2 H, CH₂O), 3.91-3.95 (m, 4 H, OCH₃, CH₂C1), 3.82 (s, 3 H, OCH₃), 3.80 (s, 3 H, OCH₃), 2.02-2.10 (m, 2 H, CH₂); ¹³C NMR δ 160.2 (CO), 156.2 (C 2"), 154.4 (OCONH), 149.1 (C 5'), 148.1 (C 4"), 141.4 (C 3a), 139.9 (C 6'), 139.0 (C 7^*), 134.4 (C 5), 132.8 (C 1"), 130.8 (C 9a), 129.4 (C 2'), 128.5 (C 6"), 127.1 (C 8), 125.4 (C 5a, C 7a'), 124.3 (C 7), 123.8 (C 9), 123.2 (C 6), 123.1 (C 3a'), 122.0 (C 9b), 115.4 (C 5"), 113.0 (C 4), 106.2 (C 3'), 106.0 (C 3"), 98.0 (C 4'), 65.1 (CH₂O), 61.3 (CH₂O), 61.0 (OCH₃), 60.9 (OCH₃), 60.7 (CH₂O), 55.9 (OCH₃), 54.9 (C 2), 47.5 (CH₂C1), 41.2 (C 1), 29.6 (CH₂); MS (FAB⁺) m/z 801 (MH⁺, 0.5%), 799 (MH⁺, 0.8); HRMS (FAB⁺) calc. for C₃₆H₃₇ ³⁵ClN₄O₁₃P (MH⁺) m/z 799.1783, found 799.1757; calc. for C₃₆H₃₇ ³⁷ClN₄O₁₃P (MH⁺) m/z 801.1754, found 801.1730.

Example 41. Preparation of 2-(2,3-dihydroxypropoxy)-4-nitrobenzyI l-(chloromethyl)- 3-[(5,6,7-trimethoxy-lH-indol-2-yl)carbonyl]-2,3-dihydro-lH-benzo[e]indol-5- ylcarbamate (99).

Methyl 4-nitro-2-(2-oxiranylmethoxy)benzoate (94). A mixture of methyl 4- nitrosalicylate (66) (0.99 g, 5.02 mmol) and K₂CO₃ (1.04 g, 7.53 mmol) in DMF (25 mL) was stiπed at 20 °C for 20 min. Epichlorohydrin (0.59 mL, 7.53 mmol) was added and the mixture stirred at 100 °C for 2 h. The mixture was poured into water, extracted with EtOAc (3 x 100 mL), the combined organic extracts washed with water (2 50 mL), brine (50 mL), dried, and the solvent evaporated. The residue was purified by chromatography, eluting with a gradient (20-50%) EtOAc/light petroleum, to give (i) starting material (0.18 g, 18%) and (ii) 94 (0.75 g, 59 %) as a colourless solid, mp (EtOAc/light petroleum) 62-63 °C; 'H NMR δ 7.91 (dd, J= 7.7, 1.0 Hz, 1 H, H 5), 7.84-7.86 (m, 2 H, H 3, H 6), 4.49 (dd, J= 11.2, 2.4 Hz, 1 H, H 3'), 4.14 (dd, J= 1 1.2, 5.2 Hz, 1 H, H 3'), 3.94 (s, 3 H, OCH₃), 3.40-3.44 (m, 1 H, H 2'), 2.91-2.97 (m, 2 H, H 1 '); ¹³C NMR δ 165.0 (CO₂), 158.1 (C 2), 150.6 (C 4), 132.3 (C 6), 126.1 (C 1), 1 15.6 (C 5), 108.4 (C 3), 69.6 (OCH₃), 52.6 (CH₂O), 49.7 (CH₂O), 44.3 (C 2'); MS (Cl, NH₃) m/z 295 (M+CH₃CN⁺, 70%), 259 (MH⁺, 100%); Anal. (C_nH_uNO₆) C, H, N.

Methyl 2-(2,3-dihydroxypropoxy)-4-nitrobenzoate (95). Perchloric acid (1 mL) and water (3 mL) was added to a stirred solution of 94 (205 mg, 0.81 mmol) in THF (20 mL) and the solution stirred at 20 °C for 16 h. The solvent was evaporated and the residue partitioned between EtOAc (50 mL) and water (50 mL). The organic fraction was washed with water (50 mL), brine (25 mL), dried, and the solvent evaporated. The residue was purified by chromatography, eluting with 70% EtOAc/light petroleum, to give 95 (172 mg, 78%) as an oil which solidified on standing, mp 60-65 °C; 'H NMR δ 8.02 (d, J= 8.5 Hz, 1 H, H 6), 7.87 (dd, J= 8.5, 2.0 Hz, 1 H, H 5), 7.84 (d, J= 2.0 Hz, 1 H, H 3), 4.38 (dd, J- 9.3, 5.4 Hz, 1 H, H 3'), 4.23 (dd, J= 9.3, 5.4 Hz, 1 H, H 3'), 4.10-4.14 (m, 1 H, H 2'), 3.95 (s, 3 H, OCH₃), 3.88 (br d, J= 4.1 Hz, 2 H, H 1 '), 3.05 (br s, 1 H, OH), 1.95 (br s, 1 H, OH); ^,3C MR δ 164.8 (CO₂), 159.1 (C 2), 151.0 (C 4), 132.8 (C 6), 124.9 (C 1), 115.6 (C 5), 108.8 (C 3), 73.0 (CH₂O), 69.2 (C 2'), 63.2 (CH₂O), 52.8 (OCH₃); MS (Cl, NH₃) m/z 272 (MH⁺, 1%), 240 (50%), 165 (100); HRMS (Cl, NH₃) calc. for C_πH₁₄NO₇ (MH⁺) m/z 272.0770, found 272.0766. Anal. (C,,H₁₃NO₇) C, H, N.

Methyl 2-[(2,2-dimethyl-l,3-dioxoIan-4-yl)methoxy]-4-nitrobenzoate (96). 2,2- Dimethoxypropane (0.91 mL, 7.37 mmol) was added dropwise to a stirred solution of diol 95 (400 mg, 1.47 mmol) and PPTS (37 mg, 0.15 mmol) in DMF (20 mL) under N₂ and stirred at 20 °C for 24 h. The solvent was evaporated and the residue partitioned between EtOAc (100 mL) and water (100 mL). The organic fraction was washed with water (50 mL), brine (25 mL), dried, and the solvent evaporated. The residue was purified by chromatography, eluting with 30% EtOAc/light petroleum, to give 96 (458 mg, 100%) as a yellow oil, 'H NMR δ 7.90 (d, J= 8.2 Hz, 1 H, H 6), 7.84-7.88 (m, 2 H, H 3, H 5), 4.49- 4.54 (m, 1 H, H 4"), 4.25 (dd, J= 9.6, 4.6 Hz, 1 H, H 5"), 4.19 (dd, J= 8.5, 6.4 Hz, 1 H, H 2'), 4.15 (dd, J= 9.6, 4.6 Hz, 1 H, H 5"), 4.03 (dd, J= 8.5, 5.8 Hz, 1 H, H 2'), 3.94 (s, 3 H, OCH₃), 1.46 (s, 3 H, CH₃), 1.41 (s, 3 H, CH₃); ¹³C NMR δ 165.1 (CO₂), 158.2 (C 2), 150.6 (C 4), 132.2 (C 6), 126.4 (C 1), 1 15.5 (C 5), 109.9 (C 2"), 108.4 (C 3), 73.6 (C 4"), 69.8 (CH₂O), 66.5 (CH₂O), 52.6 (OCH₃), 26.6 (CH₃), 25.3 (CH₃); MS (Cl, NH₃) m/z 312 (MH⁺, 15%), 296 (95), 101 (95), 71 (100); HRMS (Cl, NH₃) calc. for C₁₄H_!8NO₇ (MH⁺) m/z 312.1083, found 312.1092.

{2-[(2,2-Dimethyl-l,3-dioxolan-4-yl)methoxy]-4-nitrophenyl}methanol (97). DIBALH (1 M in DCM, 5.1 mL, 5.1 mmol) was added to a stirred solution of ester 96 (457 mg, 1.47 mmol) in THF (50 mL) at 5 °C and the solution stirred at 5 °C for 1 h. The solution was poured into a solution of potassium sodium tartrate (1 M, 100 mL) and the mixture stirred vigorously for 20 min. The mixture was extracted with EtOAc (3 x 50 mL), the combined organic fraction washed with water (50 mL), brine (50 mL), dried, and the solvent evaporated. The residue was purified by chromatography, eluting with 20% EtOAc/light petroleum, to give 97 (385 mg, 92%) as a white solid, mp (EtOAc/light petroleum) 90-92 °C; Η NMR δ 7.87 (dd, J = 8.2, 2.1 Hz, 1 H, H 5), 7.72 (d, J = 2.1 Hz, 1 H, H 3), 7.50 (d, J = 8.2 Hz, 1 H, H 6), 4.82 (d, J= 14.1 Hz, 1 H, CH₂O), 4.70 (d, J= 14.1 Hz, 1 H, CH₂O), 4.51-4.57 (m, 1 H, H 4"), 4.23 (dd, J= 9.8, 4.0 Hz, 1 H, H 5"), 4.19 (dd, J= 9.8, 5.4 Hz, 1 H, H 2'), 4.11 (dd, J= 9.8, 5.4 Hz, 1 H, H 5"), 3.95 (dd, J= 8.7, 5.4 Hz, 1 H, H 2'), 3.25 (br s, 1 H, OH), 1.48 (s, 3 H, CH₃), 1.41 (s, 3 H, CH₃); ^,3C NMR δ 156.5 (C 2), 148.2 (C 4), 137.2 (C 1), 128.6 (C 6), 116.6 (C 5), 110.0 (C 2") 106.4 (C 3), 73.7 (CH₂O), 69.7 (CH₂O), 66.0 (CH₂O), 61.0 (CH₂O), 26.6 (CH₃), 25.0 (CH₃); MS m/z 283 (M⁺, 3%), 268 (20), 225 (30), 101 (100); HRMS calc for C₁₃H_!7NO₆ (M⁺) m/z 283.1056, found 283.1055; Anal. (C₁₃H₁₇NO₆) C, H, N.

2-[(2,2-Dimethyl-l_y3-dioxoIan-4-yl)methoxy]-4-nitrobenzyl l-(chloromethyl)-3-[(5,6,7- trimethoxy-lH-indol-2-yl)carbonyl]-2,3-dihydro-lH-benzo[e]indol-5-ylcarbamate (98). A solution of triphosgene (22 mg, 75 μmol) in DCM (3 mL) was added dropwise to a stiπed solution of amin 1 [G. J. Atwell, W. R. Wilson, W. A. Denny, Bioorg. Med. Chem. Lett., 1997, 7, 1483] (100 mg, 215 μmol) and Et₃N (60 μL, 429 μmol) in DCM (10 mL) and stiπed at °C for 2 h. A solution of alcohol 97 (73 mg, 256 μmol) in DCM (3 mL) was added, followed by nBu₂Sn(OAc)₂ (2 drops) and the solution stirred at 20 °C for 24 h. The solvent was evaporated and the residue purified by chromatography, eluting with 20%EtOAc/DCM, to give 98 (160 mg, 96%) as a gum; Η NMR δ 9.44 (s, 1 H, indole- NH), 8.94 (s, 1 H, OCONH), 7.92 (d, J= 8.5 Hz, 1 H, H 6), 7.87 (dd, J= 8.2, 2.1 Hz, 1 H, H 5"), 7.81 (d, J= 8.2 Hz, 1 H, H 9), 7.73 (d, J= 2.1 Hz, 1 H, H 3"), 7.58 (ddd, J= 8.2, 7.3, 0.7 Hz, 1 H, H 8), 745-7.51 (m, 2 H, H 7, H 6"), 7.13 (br s, 1 H, H 4), 7.02 (d, J= 2.2 Hz, 1 H, H 3'), 6.89 (s, 1 H, H 4'), 5.38 (s, 2 H, CH₂O), 4.83 (dd, J= 10.8, 1.7 Hz, 1 H, H 2), 4.69 (dd, J= 10.8, 8.7 Hz, 1 H, H 2), 4.50-4.56 (m, 1 H, H 4""), 4.23 (dd, J= 9.8, 4.0 Hz, 1 H, H 5""), 4.15-4.20 (m, 2 H, H 1, H 2'"), 4.09-4.14 (m, 4 H, OCH₃, H 5""), 3.95-4.00 (m, 5 H, OCH₃ CH₂C1, H 2'"), 3.92 (s, 3 H, OCH₃), 3.50 (dd, J= 10.9, 10.8 Hz, 1 H, CH₂C1), 1.45 (s, 3 H, CH₃), 1.39 (s, 3 H, CH₃); MS (FAB⁺) m/z 111 (MH⁺, 10%), 775 (MH⁺, 35); HRMS (FAB⁺) calc. for C₃₉H₄₀ ³⁵C1N₄O_U (MH⁺) m/z 775.2381, found 777.2379; calc. for C₃₉H₄₀ ³⁷C1N₄O_U (MH⁺) m/z 777.2535, found 777.2354.

2-(2,3-Dihydroxypropoxy)-4-nitrobenzyl l-(chloromethyI)-3-[(5,6,7-trimethoxy-lH- indol-2-yl)carbonyl]-2,3-dihydro-lH-benzo[e]indol-5-ylcarbamate (99). 1 M HCI (1 mL) was added to a stiπed suspension of 98 (160 mg, 206 μmol) in THF (20 mL) and the mixture stiπed at 20 °C for 16 h. The mixture was evaporated and the residue partitioned between DCM (50 mL) and water (50 mL). The organic fraction was washed with water (30 mL), brine (30 mL), dried, and the solvent evaporated. The residue was purified by chromatography, eluting with 50%EtOAc/DCM, to give 99 (87 mg, 56%) as a white solid, mp (MeOH/iPr₂O) 147-149 °C; "H NMR [(CD₃)₂SO] δ 11.46 (s, 1 H, indole-NH), 9.90 (s, 1 H, OCONH), 8.56 (s, 1 H, H 4), 8.12 (d, J= 8.5 Hz, 1 H, H 6), 7.98 (d, J= 8.3 Hz, 1 H, H 9), 7.92 (dd, J= 8.3, 1.9 Hz, 1 H, H 5"), 7.83 (d, J= 1.9 Hz, 1 H, H 3"), 7.69 (d, J= 8.3 Hz, 1 H, H 6"), 7.59 (dd, J= 8.2, 7.6 Hz, 1 H, H 8), 7.49 (dd, J= 8.5, 7.6 Hz, 1 H, H 7), 7.09 (d, J= 2.1 Hz, 1 H, H 3'), 6.98 (s, 1 H, H 4'), 5.33 (s, 2 H, CH₂O), 5.07 (d, J= 5.2 Hz, 1 H, OH), 4.81 (dd, J= 11.0, 9.7 Hz, 1 H, H 2), 4.73 (t, J= 5.7 Hz, 1 H, H 3'"), 4.53 (dd, J = 11.0, 3.5 Hz, 1 H, H 2), 4.32-4.37 (m, 1 H, H 1), 4.24 (dd, J= 10.0, 3.9 Hz, 1 H, CH₂C1), 4.09-4.13 (m, 1 H, H 2""), 4.02-4.06 (m, 1 H, H 3'), 3.93-3.96 (m, 4 H, OCH₃ CH₂Cl), 3.84-3.89 (m, 1 H, OH), 3.83 (s, 3 H, OCH₃), 3.81 (s, 3 H, OCH₃), 3.51 (t, J= 5.7 Hz, 2 H, H 1'"); ¹ C NMR [(CD₃)₂SO] δ 160.2 (CO), 156.2 (C 2"), 154.3 (OCONH), 149.2 (C 5'), 148.0 (C 4"), 141.5 (C 3a), 139.9 (C 6'), 139.0 (C 7'), 134.3 (C 5), 133.0 (C 1"), 130.7 (C 9a), 129.4 (C 2'), 128.0 (C 6"), 127.1 (C 8), 125.4 (C 5a, C 7a), 124.3 (C 7), 123.9 (C 9), 123.3 (C 6), 123.1 (C 3a'), 122.0 (C 9b), 1154 (C 5"), 113.0 (C 4), 106.3 (C 3'), 106.2 (C 3"), 98.0 (C 4'), 70.7 (CH₂O), 69.7 (CHOH) 62.4 (CH₂O), 61.0 (OCH₃), 60.9 (OCH₃), 60.7 (CH₂O), 55.9 (OCH₃), 54.9 (C 2), 47.5 (CH₂C1), 41.4 (C 1); MS (FAB⁺) m/z 737 (MH\ 3%), 735 (MH⁺, 8); HRMS (FAB⁺) calc. for C₃₆H₃₆ ³⁵ClN₄O_π (MH⁺) m/z 735.2069, found 735.2050; calc. for C₃₆H₃₆ ⁷ClN₄O_π (MH⁺) m/z 737.2040, found 737.2000; Anal. (C₃₆H₃₅ClN₄O_π.CH₃OH) C, H, N.

Example 4J. Preparation of 2-[3-(dimethylamino)propoxy]-4-nitrobenzyI 1- (chloromethyl)-3-[(5,6,7-trimethoxy-lH-indol-2-yl)carbonyl]-2,3-dihydro-lH- benzo[e]indol-5-ylcarbamate (102).

Methyl 2-[3-(dimethylamino)propyloxy]-4-nitrobenzoate (100). A mixture of methyl 2- hydroxy-4-nitrobenzoate (66) (1.03 g, 5.22 mmol) and K₂CO₃ (2.17 g, 15.67 mmol) in DMF (30 mL) was stiπed at 20 °C for 30 min. A solution of N-(3-chloropropyl)-NN- dimethylamine (1.24 g, 7.83 mmol) in DMF (10 mL) was added and the mixture stirred at 100 °C for 3 h. The mixture was poured into water (300 mL), extracted with EtOAc (3 x 100 mL) and the combined organic extract washed with water (2 100 mL), brine (50 mL), dried and the solvent evaporated. The residue was purified by chromatography, eluting with a gradient (20-50%) of EtOAc/light petroleum, to give 100 (1.05 g, 71%) as a pale yellow oil which was stored as the HCI salt, mp (EtOAc) 175- 177 ° C; Η ΝMR [(CD₃)₂SO] δ

10.90 (br s, 1 H, ΝHC1), 7.87-7.93 (m, 3 H, H 3, H 5, H 6), 4.32 (t, J= 6.0 Hz, 2 H, CH₂O), 3.89 (s, 3 H, OCH₃), 3.18-3.23 (m, 2 H, CH₂Ν), 2.77 (d, J= 4.8 Hz, 6 H, N(CH₃)₂), 2.18- 2.24 (m, 2 H, CH₂); ¹³C NMR [(CD₃)₂SO] δ 165.0 (CO₂), 157.3 (C 2), 150.2 (C 4), 131.6 (C 6), 126.0 (C 1), 115.3 (C 5), 108.4 (C 3), 66.5 (CH₂O), 53.7 (CH₂N), 52.6 (OCH₃), 42.0 (N(CH₃)₂), 23.3 (CH₂); Anal. (C₁₃H₁₉ClN₂O₅) C, H, N, Cl.

{2-[3-(Dimethylamino)propoxy]-4-nitrophenyl}methanol (101). DIBALH (1 M, in DCM, 13.0 mL, 13.0 mmol) was added to a stirred solution of ester 100 (1.05 g, 3.72 mmol) in THF (50 mL) at 5 °C and the solution stirred at 5 °C for 1 h. The solution was poured into a solution of potassium sodium tartrate (1 M, 100 mL) and the mixture stirred vigorously for 20 min. The mixture was extracted with EtOAc (3 100 mL), the combined organic fraction washed with water (100 mL), brine (50 mL), dried, and the solvent evaporated. The residue was purified by chromatography on alumina, eluting with a gradient (0-10%) of MeOH/EtOAc, to give 101 (0.81 g, 86%) as a pale yellow solid, mp (EtOAc) 104-105 °C; Η NMR δ 7.87 (dd, J= 8.3, 2.1 Hz, 1 H, H 5), 7.69 (d, J= 2.1 Hz, 1 H, H 3), 7.64 (d, J= 8.3 Hz, 1 H, H 6), 5.43 (br s, 1 H, OH), 4.58 (s, 2 H, CH₂O), 4.14 (t, J = 6.5 Hz, 2 H, CH₂O), 2.36 (t, J= 7.0 Hz, 2 H, CH-N), 2.15 (s, 6 H, N(CH₃)₂), 1.85-1.91 (m, 2 H, CH₂); ¹³C NMR δ 155.2 (C 2), 147.0 (C 4), 138.9 (C 1), 126.7 (C 6), 115.3 (C 5), 105.2 (C 3), 66.5 (CH₂O), 57.6 (CH₂O), 55.5 (NCH₂), 45.1 (N(CH₃)₂), 26.5 (CH₂); Anal. (C₁₂H₁₈N₂O₄) C, H, N.

2-[3-(Dimethylamino)propoxy]-4-nitrobenzyl l-(chloromethyl)-3-[(5,6,7-trimethoxy- lH-indol-2-yl)carbonyl]-2,3-dihydro-lH-benzo[e]indol-5-ylcarbamate (102). A solution of triphosgene (17 mg, 55 μmol) in DCM (2 mL) was added dropwise to a stiπed solution of amine 1 [G. J. Atwell, W. R. Wilson, W. A. Denny, Bioorg. Med. Chem. Lett., 1997, 7, 1483] (65 mg, 140 μmol) and Et₃N (44 μL, 313 μmol) in DCM (10 mL) and stiπed at 20 °C for 2 h. A solution of alcohol 101 (44 mg, 172 μmol) in DCM (2 mL) was added, followed by nBu₂Sn(OAc)₂ (2 drops) and the solution stirred at 20 °C for 24 h. The solvent was evaporated and the residue purified by chromatography, eluting with a gradient (0-20%) MeOH/EtOAc, to give 102 (57 mg, 55%) as a yellow solid which was converted to the hydrochloride salt, mp (MeOH) 176-180 °C; Η NMR [(CD₃)₂SO] δ 11.43 (s, 1 H, indole-NH), 10.47 (br s, 1 H, NH⁺C1^"), 9.92 (s, 1 H, OCONH), 8.58 (s, 1 H, H 4), 8.10 (d, J = 8.5 Hz, 1 H, H 6), 7.97 (d, J= 8.3 Hz, 1 H, H 9), 7.93 (dd, J= 8.4, 2.0 Hz, 1 H, H 5"), 7.82 (d, J= 2.0 Hz, 1 H, H 3"), 7.71 (br d, J= 84 Hz, 1 H, H 6"), 7.56-7.61 (m, 1 H, H 8), 7.46-7.51 (m, 1 H, H 7), 7.10 (d, J= 2.1 Hz, 1 H, H 3'), 6.97 (s, 1 H, H 4'), 5.34 (s, 2 H, CH₂O), 4.81 (dd, J= 10.8, 9.5 Hz, 1 H, H 2), 4.53 (dd, J= 10.8, 1.7 Hz, 1 H, H 2), 4.33- 4.38 (m, 1 H, H 1), 4.30 (t, J= 5.9 Hz, 2 H, CH₂O), 4.07 (dd, J= 11.1, 2.9 Hz, 1 H, CH₂C1), 3.94-3.97 (m, 4 H, CH₂C1, OCH₃), 3.83 (s, 3 H, OCH₃), 3.81 (s, 3 H, OCH₃), 3.23-3.27 (t, J = 7.5 Hz, 2 H, CH₂N), 2.75 (s, 6 H, N(CH₃)₂), 2.17-2.23 (m, 2 H, CH₂); ¹³C NMR [(CD₃)₂SO] δ 160.2 (CO), 155.8 (C 2"), 154.3 (OCONH), 149.2 (C 5'), 148.0 (C 4"), 141.5 (C 3a), 139.9 (C 6'), 138.9 (C 7'), 134.3 (C 5), 132.9 (C 1"), 130.7 (C 2'), 129.5 (C 9a), 128.5 (C 6"), 127.2 (C 8), 125.4 (C 7a'), 124.4 (C 7), 123.7 (C 9), 123.3 (C 6), 123.1 (C 3a'), 122.1 (C 9b), 121.2 (C 5a), 115.7 (C 5"), 113.0 (C 4), 106.3 (C 3', C 3"), 98.0 (C 4'), 66.8 (CH₂O), 61.0 (OCH₃), 60.9 (OCH₃), 60.7 (CH₂O), 55.9 (OCH₃), 54.9 (C 2), 53.7 (CH₂N), 47.5 (CH₂C1), 42.0 (N(CH₃)₂), 41.1 (C 1), 23.6 (CH₂); Anal. (C₃₈H₄₁ClN₅O₉.2HCl): C, H, N.

Example 4K. Preparation of 2-[3-(4-morpholinyl)propoxy]-4-nitrobenzyI 1- (chloromethyl)-3-[(5,6,7-trimethoxy-lH-indol-2-yl)carbonyl]-2,3-dihydro-lH- benzo [e] indol-5-ylcarbamate (105). Methyl 2-[3-(4-morpholinyl)propoxy]-4-nitrobenzoate (103). A mixture of methyl 2- hydroxy-4-nitrobenzoate (1.0 g, 5.12 mmol) and K₂CO₃(1.06 g, 7.68 mmol) in DMF (20 mL) was stiπed at 20 °C for 30 min. A solution of 4-(3-chloropropyl)morpholine (0.98 g, 7.68 mmol) in DMF (5 mL) was added and the mixture stirred at 100 °C for 6 h. The mixture was cooled to 20 °C and poured into water (300 mL) and extracted with EtOAc (3 x 100 mL). The combined organic fraction was washed with water (2 x 50 mL), brine (50 mL), dried, and the solvent evaporated. The residue was purified by chromatography, eluting with EtOAc, to give 103 (1.33 g, 80%) as an oil, 'H NMR δ 7.88 (d, J= 9.1 Hz, 1 H, H 6), 7.81 (m, 2 H, H 3, H 5), 4.21 (t, J= 6.3 Hz, 2 H, CH₂O), 3.93 (s, 3 H, OCH₃), 3.69-3.74 (m, 4 H, 2 x CH₂O), 2.57 (t, J= 7.0 Hz, 2 H, CH₂N), 247-2.51 (m, 4 H, 2 x CH₂N), 2.02-2.07 (m, 2 H, CH₂); ¹³C NMR δ 165.3 (CO₂), 158.6 (C 2), 150.6 (C 4), 132.0 (C 6), 126.2 (C 1), 114.8 (C 5), 107.8 (C 3), 67.6 (CH₂O), 66.9 (2 CH₂O), 55.0 (CH₂N), 53.7 (2 x CH₂N), 52.5 (OCH₃), 25.9 (CH₂). Compound 103 was conveniently stored as the hydrochloride salt, mp (EtOAc) 160-163 °C; Anal. (C₁₅H₂₀N₂O₆.HC1) C, H, Cl. N, calc. 7.8, found 9.1%.

{2- [3-(4-MorpholinyI)propoxy] -4-nitrophenyl} methanol (104). A solution of ester 103 (1.33 g, 4.10 mmol) in THF (100 mL) was added dropwise to a stirred solution of DIBALH (1 M in DCM, 13.5 mL, 13.5 mmol) at 5 °C and the solution stirred at 5 °C for 1 h. The solution was carefully poured into 1 M HCI (50 mL) and stirred for 10 min. The solution was concentrated under reduced pressure, neutralised and extracted with EtOAc ( 3 x 100 mL). The combined organic fraction was dried and the solvent evaporated. The residue was purified by chromatography on alumina, eluting with a gradient (0-10%) MeOH/EtOAc, to give 104 (1.07 g, 88%) as a tan solid, mp (EtOAc) 105-106 °C; Η NMR δ 7.83 (dd, J= 8.2, 2.1 Hz, 1 H, H 5), 7.70 (d, J= 2.1 Hz, 1 H, H 3), 7.46 (d, J= 8.2 Hz, 1 H, H 6), 4.71 (s, 2 H, CH₂O), 4.18 (t, J= 6.0 Hz, 2 H, CH₂O), 3.74-3.77 (m, 4 H, 2 x CH₂O), 2.56 (dd, J = 6.7, 6.5 Hz, 2 H, CH₂N), 245-249 (m, 4 H, 2 x CH₂N), 2.01-2.06 (m, 2 H, CH₂); ¹³C NMR δ 156.7 (C 2), 148.2 (C 4), 137.2 (C 1), 128.2 (C 6), 116.1 (C 5), 106.2 (C 3), 67.7 (CH₂O), 66.5 (2 x CH₂O), 60.7 (CH₂O), 56.3 (CH₂N), 53.9 (2 x CH₂N) 25.5 (CH₂); Anal. (C₁₄H₂₀N₂O₅) C, H, N.

2-[3-(4-Morpholinyl)propoxy]-4-nitrobenzyl l-(chloromethyl)-3-[(5,6,7-trimethoxy- lH-indol-2-yl)carbonyI]-2,3-dihydro-lH-benzo[e]indol-5-ylcarbamate (105). A solution of triphosgene (15.5 mg, 52 μmol) in DCM (2 mL) was added dropwise to a stirred solution of amine 1 [G. J. Atwell, W. R. Wilson, W. A. Denny, Bioorg. Med. Chem. Lett., 1997, 7, 1483] (52 mg, 133 μmol) and Et₃N (42 μL, 299 μmol) in DCM (10 mL) and stirred at °C for 2 h. A solution of alcohol 104 (49 mg, 164 μmol) in DCM (2 mL) was added, followed by nBu₂Sn(OAc)₂ (2 drops) and the solution stirred at 20 °C for 24 h. The solvent was evaporated and the residue purified by chromatography, eluting with a gradient (0-10%) MeOH/EtOAc, to give 105 (96 mg, 92%) as a tan powder mp (EtOAc) 102-107 °C; 'H NMR δ 9.48 (s, 1 H, indole-NH), 8.93 (s, 1 H, OCONH), 7.91 (d, J= 8.5 Hz, 1 H, H 6), 7.78-7.84 (m, 2 H, H 9, H 5"), 7.73 (d, J= 1.8 Hz, 1 H, H 3"), 7.57 (ddd, J= 8.2, 7.0,

1.0 Hz, 1 H, H 8), 7.50-7.53 (m, 1 H, H 6"), 7.45 (ddd, J= 8.5, 7.0, 1.0 Hz, 1 H, H 7), 7.28 (br s, 1 H, H 4), 7.00 (d, J= 2.2 Hz, 1 H, H 3'), 6.88 ( s, 1 H, H 4'), 5.36 (s, 2 H, CH₂O),

4.81 (dd, J= 10.8, 1.8 Hz, 1 H, H 2), 4.68 (dd, J= 10.8, 8.7 Hz, 1 H, H 2), 4.16-4.22 (m, 3 H, CH₂O, CH₂C1), 4.08 (s, 3 H, OCH₃), 3.93-3.99 (m, 4 H, H 1, OCH₃), 3.92 (s, 3 H, OCH₃), 3.69 (t, J= 4.6 Hz, 4 H, 2 x CH₂O), 3.49 (t, J= 10.9 Hz, 1 H, CH₂C1), 2.55 (t, J =

7.1 Hz, 2 H, CH₂N), 243-249 (m, 4 H, 2 x CH₂N), 2.00-2.08 (m, 2 H, CH₂); ¹³C NMR δ 1604 (CO), 156.7 (C 2"), 154.0 (OCONH), 150.2 (C 5'), 148.6 C 4"), 141.7 (C 3a), 140.6

(C 6'), 138.9 (C 7'), 133.9 (C 5), 132.2 (C 1"), 129.8 (C 2'), 129.6 (C 9a), 128.8 (C 6"), 127.5 (C 8), 125.7 (C 7a'), 125.0 (C 7), 123.6 (C 3a'), 123.2 (C 9), 122.4 (C 6, C 9b), 121.6 (C 5a), 115.7 (C 5"), 112.2 (C 4), 106.5 (C 3'), 106.1 (C 3"), 97.7 (C 4'), 67.1 (CH₂O), 66.8 (2 x CH₂O), 61.9 (CH₂O), 61.5 (OCH₃), 61.1 (OCH₃), 56.3 (OCH₃), 55.2 (C 2), 54.9 (CH₂N), 53.6 (2 x CH₂N), 45.8 (CH₂C1), 434 (C 1), 26.1 (CH₂); MS (FAB⁺) m/z 788 (MH⁺, 6%), 790 (MH⁺, 3); HRMS (FAB⁺) calc. for C₄₀H₄₃ ³⁵C1N₅O₁₀ (MH⁺) m/z 788.2699, found 788.2721; calc. for C₄₀H₄₃ ³⁷C1N₅O₁₀ (MH⁺) m/z 790.2699, found 790.2728; Anal. (C₄₀H₄₂C1N₅O₁₀.¹/₂H₂O) C, H, N.

Example 4L. Preparation of 2-[3-(4-morpholinyl)propoxy]-4-nitrobenzyl bis(3-{[(5- methyl-4-acridinyl)carbonyl]amino}propyl)carbamate (107). DIEA (0.3 mL, 3 mmol) was added to a suspension of carbamate dihydrochloride 91 (44 mg, 0.5 mmol) in DCM (10 mL) at 5 °C and the mixture stiπed for 10 min. Methanesulfonyl chloride (0.1 mL), was added and the mixture stirred for 30 min. MeOH (2 mL) was added, the mixture stirred for 10 min, and the solvent evaporated. The residue was purified by chromatography on alumina-90, eluting with 1 %MeOH/40%EtOAc/DCM to give the crude mesylate 106 (42 mg, 95%) as a yellow solid, 'H NMR δ 1 1.94 (s, 1 H, NH), 11.85 (s, 1 H, NH), 8.94 (m, 2 H), 8.77 (m, 2 H), 8.07 ( , 2 H), 7.81 (m, 2 H), 7.62 (m, 4 H), 7.43 (m, 2 H), 7.30 (d, J = 2.0 Hz, 1 H, H 3'"), 7.05 (d, J= 8.4 Hz, 1 H, H 6'"), 6.95 (dd, J= 8.4, 2.0 Hz, 1 H, H 5'"), 5.02 (s, 2 H, CH₂O), 4.39 (t, 2 H, CH₂O), 3.98 (t, 2 H), 3.73-3.58 (m, 8 H), 3.02 (s, 3 H, CH₃SO₂), 2.85 (s, 3 H, CH₃), 2.76 (s, 3 H, CH₃), 2.20-2.05 (m, 6 H). A solution of mesylate 106 (42 mg, 0.047 mmol) in morpholine (0.5 mL) was stiπed at 20 °C for 20 hrs. The reaction mixture was purified by chromatography on alumina-90, eluting with l%MeOH/40%EtOAc/DCM to give 107 (38 mg, 91%) as a yellow solid, 'H NMR δ 11.94 (s, 1 H, NH), 11.86 (s, 1H, N H), 8.89-8.91 (m, 2 H), 8.73-8.77 (m, 2 H), 8.06-8.08 (m, 2 H), 7.80-7.84 (m, 2 H), 7.59-7.64 (m, 4 H), 7.42-746 (m, 2 H), 7.32 (d, J= 2.0 Hz, 1 H, H 3'"), 7.06 (d, J= 8.4 Hz, 1 H, H 6'"), 6.95 (dd, J= 8.4, 2.0 Hz, 1 H, H 5'"), 5.03 (s, 2 H, CH₂O), 3.92 (t, 2 H), 3.75-3.67 (m, 8 H, 4 x CH₂N), 3.59 (m, 4 H, 2 x CH₂), 2.86 (s, 3 H, CH₃), 2.74 (s, 3 H, CH₃), 2.46 (br s, 6 H, CH₂N), 2.18-2.04 (m, 4 H), 1.93 (br s, 2 H); HRMS (FAB⁺) calc. for (C₅₁H₅₄N₇O₈) (MH⁺) m/z 8924034, found 8924055.

Example 4M. Preparation of 4-{2-[({[bis(3-{[(5-methyl-4- acridinyl)carbonyl] amino}propyl)amino] carbonyl}oxy)methyl]-5- nitrophenoxyjbutanoic acid (111).

Methyl 2-(4-tert-butoxy-4-oxobutoxy)-4-nitrobenzoate (108). A mixture of methyl 2- hydroxy-4-nitrobenzoate (66) (0.61 g, 3.09 mmol) and K₂CO₃ (0.64 g, 4.64 mmol) in DMF (20 mL) was stiπed at 20 °C for 30 min. A solution of tβrt-butyl 4-bromobutanoate (1.04 g, 4.64 mmol) in DMF (5 mL) was added and the mixture stiπed at 100 °C for 6 h. The mixture was cooled to 20 °C, poured into water (300 mL) and extracted with EtOAc (3 100 mL). The combined organic fraction was washed with water (2 50 mL), brine (50 mL), dried, and the solvent evaporated. The residue was purified by chromatography, eluting with 20%EtOAc/light petroleum, to give 108 (0.86 g, 82%) as an oil, IR N 2978, 1728, 1532, 1350, 1285, 1250, 1155 cm^"1; 'H NMR δ 7.89 (d, J= 8.5 Hz, 1 H, H 6), 7.85 (dd, J= 8.5, 2.0 Hz, 1 H, H 5), 7.79 (d, J= 2.0 Hz, 1 H, H 3), 4.17 (t, J= 6.2 Hz, 2 H, CH₂O), 3.93 (s, 3 H, OCH₃), 2.47 (t, J= 7.3 Hz, 2 H, CH₂CO), 2.11-2.16 (m, 2 H, CH₂), 1.49 (s, 9 H, CH₃); ^,3C NMR δ 172.3 (CO₂), 165.4 (CO₂), 158.5 (C 2), 150.7 (C 4), 132.1 (C 6), 126.2 (C 1), 115.0 (C 5), 107.9 (C 3), 80.6 (OC(CH₃)₃), 68.4 (CH₂O), 52.5 (OCH₃), 31.5 (CH₂), 28.1 (OC(CH₃)₃), 24.4 (CH₂); MS m/z 339 (M⁺, 1%), 308 (2), 197 (50), 87 (90), 57 (100); HRMS calc. for C₁₆H₂₁NO₇ (M⁺) m/z 339.1318, found 339.1314.

2-(4-/ert-Butoxy-4-oxobutoxy)-4-nitrobenzoic acid (109). A mixture of ester 108 (0.61 g, 1.80 mmol) and NaOH (1 M, 9 mL, 9 mmol) in MeOH (20 mL) was stirred at 20 °C for 2 h. The mixture was extracted with diethyl ether (20 mL) and the pH adjusted to 4 with 1 M HCI. The mixture was extracted with EtOAc (3 50 mL), the combined organic fraction washed with brine (50 mL), dried and the solvent evaporated. The residue was crystallized to give 109 as a white solid, mp (EtOAc/light petroleum) 76-77 °C; IR N 1723, 1678, 1532, 1350, 1260, 1154 cm^"1; Η NMR [(CD₃)₂SO] δ 13.0 (br s, 1 H, CO₂H), 7.80-7.86 (m, 3 H, H 3, H 5, H 6), 4.20 (t, J= 6.2 Hz, 2 H, CH₂O), 240-246 (m, 2 H, CH₂CO), 1.92-1.99 (m, 2 H, CH₂), 1.40 (s, 9 H, CH₃); ¹³C NMR [(CD₃)₂SO] δ 174.0 (CO₂), 171.8 (CO₂), 166.2 (C 2), 157.0 (C 4), 130.9 (C 6), 128.3 (C 1), 115.1 (C 5), 107.9 (C 3), 79.7 (OC(CH₃)₃), 68.0 (CH₂O), 31.0 (CH₂), 27.7 (OC(CH₃)₃), 24.0 (CH₂); Anal. (C₁₅H₁₉NO₇.¹/₄H₂O) C, H, N.

tert-Butyl 4-[2-(hydroxymethyl)-5-nitrophenoxy]butanoate (110). BH₃.DMS (0.28 mL, 2.8 mmol) was added to a stirred solution of acid 109 and trimethyl borate (0.64 mL, 5.66 mmol) in THF (50 mL) and the solution heated at reflux temperature under N₂ for 3 h. The solution was cooled to 20 °C, MeOH (2 mL) added carefully and the mixture stiπed for 5 min. Water (2 mL) was carefully added, the solution stirred for 5 min, 1 M aq. citric acid solution added and the mixture stirred for 30 min. The mixture was extracted with EtOAc (3 60 mL), the combined organic fraction washed with water (50 mL), brine (30 mL), dried, and the solvent evaporated. The residue was purified by chromatography, elutiing with a gradient (30-50%) of EtOAc/light petroleum, to give 110 (0.30 g, 68%) as a white solid, mp (EtOAc/light petroleum) 42-43 °C; IRN 3434, 1726, 1524, 1346, 1248, 1155 cm^" '; Η NMR δ 7.85 (dd, J= 8.2, 2.1 Hz, 1 H, H 5), 7.68 (d, J= 2.1 Hz, 1 H, H 3), 7.53 (d, J = 8.2 Hz, 1 H, H 6), 4.76 (d, J= 4.6 Hz, 2 H, CH₂O), 4.12 (t, J= 6.2 Hz, 2 H, CH₂O), 2.54 (br t, J= 5.0 Hz, 1 H, OH), 2.45 (t, J= 7.2 Hz, 2 H, CH₂CO), 2.11-2.18 (m, 2 H, CH₂), 1.50 (s, 9 H, CH₃); ¹³C NMR δ 172.3 (CO₂), 156.2 (C 2), 148.1 (C 4), 136.8 (C 1), 127.0 (C 6), 116.0 (C 5), 105.7 (C 3), 80.9 (OC(CH₃)₃), 67.7 (CH₂O), 60.6 (CH₂O), 31.9 (CH₂), 28.1 (OC(CH₃)₃), 24.3 (CH₂); MS (Cl, NH₃) m/z 329 (M⁺+NH₃, 5%), 312 (MH⁺, 2), 273 (100); HRMS (Cl, NH₃) calc. for C_l5H₂₂NO₆(MH⁺) m/z 312.1447, found 312.1448. Anal. (C₁₅H₂₂NO₆) C, H, N.

4-{2-[({[Bis(3-{[(5-methyl-4- acridinyl)carbonyl]amino}propyl)amino]carbonyl}oxy)methyl]-5- nitrophenoxy}butanoic acid (113). A solution of alcohol 110 (19 mg, 0.06 mmol) and DIEA (25 μL, 140 μmol) in DCM (2 mL) was added dropwise to a solution of triphosgene (10 mg, 35 μmol) in DCM (1.5 mL) over 30 minutes at 5 °C and the solution stirred for 1 hr. A solution of NN-bis[3-(5-methylacridine-4-carboxamido)propyl]amine (111) [S. A. Gamage, J. A. Spicer, G. J. Atwell, G. J. Finlay, B. C. Baguley, W. A. Denny, J. Med. Chem., 1999, 42, 2383-2393] (24 mg, 42 μmol) and DIEA (4 μL, 240 μmol) in DCM (2 mL) was added and the solution stiπed at 20 °C for 16 h. The solvent was evaporated and the residue was purified by chromatography on alumina-90, eluting with l%MeOH/60%EtOAc/DCM to give crude ester 112 (34 mg, 89%) as a yellow foam, 'H ΝMR δ 11.90 (s, 1 H, ΝH), 11.86 (s, 1 H, ΝH), 8.85-8.95 (m, 2 H), 8.66-8.76 (m, 2 H), 8.02-8.08 (m, 2 H), 7.78-7.87 (m, 2 H), 7.50-7.64 (m, 4 H), 7.38-746 (m, 2 H), 7.25 (d, J = 2.0 Hz, 1 H, H 3'), 7.01 (d, J= 8.3 Hz, 1 H, H 6'), 6.89 (dd, J= 8.3, 2.0 Hz, 1 H, H 5'), 4.77 (s, 2 H, CH₂O), 3.84-3.88 (m, 2 H), 3.58-3.73 (m, 8 H), 2.83 (s, 3 H, CH₃), 2.73 (s, 3 H, CH₃), 242-346 (m, 2 H), 2.10-2.17 (m, 4 H), 2.00-2.02 (m, 2 H), 1.45 (s, 9 H); ¹³C ΝMR δ 172.2, 166.2, 156.2, 155.6, 155.3, 147.4, 147.0 (2), 145.2 (2), 137.9 (2), 136.9, 135.8, 1354 (2), 135.2, 132.6, 132.2 (2), 131.0 (2), 127.9 (2), 126.5, 126.4, 126.2, 126.1 (2), 125.8 (2), 125.3, 116.0, 115.1, 105.7, 104.8, 67.7, 61.6, 60.5, 45.9, 45.1, 37.7, 37.0, 31.9, 31.6, 29.2, 28.6, 28.1, 24.3, 24.3, 18.9, 18.8.

Ester 112 (80 mg, 88 μmol) was added to a HCI saturated solution of MeOH (20 mL) and DCM (20 mL) at 5 °C and the solution stood for 3 days at 5 °C. The solvent was evaporated and the residue crystallized to give 113 (45 mg, 58%) as a yellow solid, mp (MeOH/EtOAc/light petroleum) 128-130°C; 'H ΝMR [(CD₃)₂SO] δ 11.39 (s, 2 H, 2 COΝH), 9.15 (s, 1 H), 9.08 (s, 1 H), 8.68 (br s, 2 H), 8.25 (br s, 2 H), 7.95 (br s, 2 H), 7.65 (br s, 4 H), 7.49 (br s, 2 H), 7.32 (d, J= 2.0 Hz, 1 H), 7.00 (d, J= 8.3 Hz, 1 H), 6.93 (dd, J = 8.3, 2.0 Hz, 1 H), 4.77 (s, 2 H, CH₂O), 3.88-3.91 (m, 2 H), 3.50-3.58 (m, 8 H), 2.77 (s, 3 H, CH₃), 2.66 (s, 3 H, CH₃), 2.01 (br s, 4 H), 1.87-1.93 (m, 2 H); Anal. (C₄₈H₄₆Ν₆O₉-2HC1.2H₂O) C, H, N.

Example 5A. Preparation of (l-methyl-2-nitro-l/7-imidazol-5-yl)methyl bis(2- chloroethyl)carbamate (117). l-Methyl-2-nitro-l /-imidazole-5-carboxylic acid (114). Sodium hydroxide solution (1 M, 125 ml, 125 mmol) was added slowly to a stiπed suspension of ethyl l-methyl-2-nitro- lH-imidazole-5-carboxylate (114) [B. Cavalleri, R. Ballotta, G.C. Lancini. J. Heterocyclic Chem. 1972, 9, 979] (5.0 g, 25.1 mmol) in water (50 mL) and the mixture stiπed at 20 °C until complete dissolution occuπed. The pH of the solution was adjusted to 3 with 5 N HCI and the mixture extracted with EtOAc (3 x 100 mL). The combined organic fractions were dried and the solvent evaporated to give 114 (4.29 g, 100%), as white crystals, mp 160-161 °C (lit. (B. Cavalleri, R. Ballotta, V. Arioli, G.C. Lancini, J. Med. Chem. 1973, 16, 557) (EtOAc) 161-163 °C); 'H NMR [(CD₃)₂SO] δ 13.60 (br s, 1 H, CO₂H), 7.37 (s, 1 H, H 4), 4.20 (s, 3 H, NCH₃); ^, C NMR [(CD₃)₂SO] δ 160.3, 147.2, 133.7, 127.0, 35.0.

(l-methyl-2-nitro-lH-imidazol-5-yl)methanol (115). A solution of CDI (7.0 g, 43.1 mmol) and 114 was stirred at 20 °C for 30 min and then added to a stiπed solution of NaBH₄(4.07 g, 108 mmol) in EtOH (10 mL) and the mixture stiπed at 20 °C for 1 h. 5 M HCI (20 mL) was added carefully and the mixture stiπed for 30 min. The solvent was evaporated and the residue purified by chromatography, eluting with EtOAc, to give 115 (2.23 g, 68%) as a white solid, mp 138-140 °C (lit. [B. Cavalleri; R. Ballotta; V. Arioli; G.C. Lancini, J. Med. Chem. 1973, 16, 557] 142-144 °C); Η NMR [(CD₃)₂SO] 57.12 (s, 1 H, H 4), 5.49 (br s, 1 H, OH), 4.55 (s, 2 H, CH₂O), 3.92 (s, 3 H, NCH₃); ¹³C NMR [(CD₃)₂SO] δ 145.6, 138.6, 126.5, 52.9, 34.0.

(l-Methyl-2-nitro-l//-imidazol-5-yl)methyl 4-nitrophenyl carbonate (116). A solution of 4-nitrophenylchloroformate (0.67 g, 3.34 mmol) in THF (5 mL) was added to a stirred solution of alcohol 115 (0.50 g, 3.18 mmol) and pyridine (283 μL, 3.50 mmol) in THF (50 mL) at 20 °C under N₂. The solution was stirred at 20 °C for 16 h, the solvent evaporated and the residue dissolved in EtOAc (lOOmL). The solution was washed with water (2 x 50 mL), brine (50 mL), dried and the solvent evaporated. The residue was purified by chromatography, eluting with 50% EtOAc/light petroleum, to give 116 (0.87 g, 84%) as a white solid, mp (EtOAc) 156.5-157.5 °C; IR N 1771, 1537, 1359 cm^"1; 'H NMR

[(CD₃)₂SO] δ 8.33 (ddd, J= 9.1, 3.2, 2.1 Hz, 2 H, H 3, H 5), 7.59 (ddd, J= 9.1, 3.2, 2.1 Hz, 2 H, H 2, H 6), 7.37 (s, 1 H, H 4'), 5.48 (s, 2 H, CH₂O), 4.00 (s, 3 H, NCH₃); ¹³C NMR [(CD₃)₂SO] δ 155.1, 151.4, 146.3, 145.2, 131.5, 129.6, 125.4 (2), 122.5 (2), 59.4, 34.3; Anal. (C₁₂H₁₀N₄O₇) C, H. N calc. 17.4, found 16.7%.

(l-Methyl-2-nitro-lH-imidazol-5-yI)methyl bis(2-chloroethyl)carbamate (117). A solution of carbonate 116 (0.68 g, 2.11 mmol) in pyridine (3 mL) was added to a solution of bis-(2-chloroethyl)amine hydrochloride (0.75 g, 4.22 mmol) in pyridine (30 mL) under N₂. The solution was stiπed at 20 °C for 16 h and the solvent evaporated. The residue was dissolved in DCM (100 mL) and washed with 2% citric acid solution (2 x 50 mL), water (50 mL), brine (50 mL), dried and the solvent evaporated. The residue was purified by chromatography, eluting with 50% EtOAc/light petroleum, to give 117 (0.51 g, 74%) as white crystals, mp (EtOAc) 100-101 °C; IR N 1703, 1489, 1344 cm^"1; 'H NMR δ 7.23 (s, 1 H, H 4), 5.21 (s, 2 H, CH₂O), 4.05 (s, 3 H, NCH₃), 3.58-3.70 (m, 8 H, 2 x CH₂N, 2 x CH₂C1); ¹³C NMR δ 154.8, 144.5, 132.1, 129.7, 56.2, 50.8 (2), 41.6 (2), 34.3; Anal. (C₁₀H₁₄C1₂N₄O₄) C, H, N.

Example 5B. Preparation of (l-methyl-2-nitro-lH-imidazol-5-yl)methyl 4-[bis(2- chIoroethyl)amino]phenylcarbamate (123).

N^V-Bis(2-{[tert-butyl(dimethyl)silyl]oxy}ethyl)-4-nitroaniline (119). A solution of TBDMSC1 (4.20 g, 27.9 mmol) in DMF (15 mL) was added to a stirred solution of NN- bis(2-hydroxyethyl)-4-nitroaniline (118) (3.0 g, 13.26 mmol) and imidazole (3.79 g, 55.7 mmol) in DMF (50 mL) and the solution stirred at 20 °C for 48 h. The solvent was evaporated and the residue partitioned between EtOAc (150 mL) and water (150 mL). The organic fraction was washed with water (2 x 200 mL), dried, and the solvent evaporated.The residue was purified by chromatography, eluting with 10% EtOAc/light petroleum, to give 119 (5.72 g, 95%) as a white solid, mp (pet. ether) 48-49 °C; IR Ν 1597, 1520, 1300, 1202, 1107 cm^"1; Η ΝMR δ 8.07 (ddd, J= 9.5, 3.5, 2.1 Hz, 2 H, H 3, H 5), 6.67 (ddd, J= 9.5, 3.5, 2.1 Hz, 2 H, H 2, H 6), 3.80 (dd, J= 6.0, 5.7 Hz, 4 H, 2 x CH₂Ν), 3.63 (dd, J= 5.9, 5.7 Hz, 4 H, 2 CH₂O), 0.86 (s, 18 H, 2 x SiC(CH₃)₃), 0.01 (s, 12 H, 2 x Si(CH₃)₂); ¹³C NMR δ 153.0, 138.6, 126.2 (2), 110.4 (2), 60.2 (2), 53.6 (2), 25.8 (6), 18.2 (2), -5.5 (4); MS (DEI) m/z 454 (M⁺, 10%), 439 (5), 397 (10), 309 (100); HRMS (DEI) calc. for C₂₂H₄₂N₂O₄Si₂ (M⁺) m/z 454.2683, found 454.2668; Anal. (C₂₂H₄₂N₂O₄Si₂) C, H, N.

N¹^V¹-Bis(2-{[tert-butyl(dimethyl)silyl]oxy}ethyl)-l,4-benzenediamine (120). A mixture of 119 (1.54 g, 3.39 mmol) and Pd/C (50 mg) in EtOAc/EtOH (1 : 1) (50 mL) was stirred under hydrogen (60 psi) for 30 minutes, filtered through celite, washed with EtOH (2 x 10 mL) and the solvent evaporated to give crude benzenediamine (120) as an oil that was used directly without further purification or characterization. (l-Methyl-2-nitro-lH-imidazol-5-yl)methyl 4-[bis(2-{[tert- butyl(dimethyl)silyl]oxy}ethyl)amino]phenylcarbamate (121). A solution of carbonate 116 (0.87 g, 2.68 mmol), 120 (3.39 mmol), and pyridine (217 μL, 2.68 mmol) in THF (50 mL) was stiπed at 20 °C for 48 h. The solvent was evaporated and the residue partitioned between EtOAc (100 mL) and water (100 mL). The organic fraction was washed with water (2 50 mL), brine (50 mL), dried, and the solvent evaporated. The residue was purified by chromatography, eluting with a gradient (20-50%) of EtOAc/light petroleum to give 121 (1.37 g, 84%) as a white solid, mp 143-144 °C; IRN 3258, 1721, 1539, 1257, 1103 cm^'1; 'H NMR [(CD₃)₂SO] δ 7.23 (s, 1 H, H 4'), 7.15 (br d, J= 8.9 Hz, 2 H, H 3, H 5), 6.63 (d, J= 8.9 Hz, 2 H, H 2, H 6), 6.52 (br s, 1 H, OCONH), 5.20 (s, 2 H, CH₂O), 4.06 (s, 3 H, NCH₃), 3.73 (dd, J= 6.5, 6.3 Hz, 4 H, 2 x CH₂O), 3.47 (dd, J= 6.5, 6.3 Hz, 4 H, 2 x CH₂N), 0.88 (s, 18 H, 2 x Si(C(CH₃)₃), 0.02 (s, 12 H, 2 x Si(CH₃)₂); ¹³C NMR [(CD₃)₂SO] δ 152.9, 146.1, 145.4, 132.5, 129.6, 1254, 121.7 (2), 111.8 (2), 60.3 (2), 55.2, 53.6 (2), 34.3, 26.0 (6), 18.2 (2), -5.4 (4); Anal. (C₂₈H₄₉N₅O₆Si₂) C, H, N.

(l-Methyl-2-nitro-lH-imidazol-5-yl)methyl 4-[bis(2- hydroxyethyl)amino]phenylcarbamate (122). TBAF (1 M in THF, 3.9 mL, 3.9 mmol) was added to dropwise to a stirred solution of 121 (1.07 g, 1.76 mmol) in THF (30 mL) at 5 °C. The solution was stirred for 30 minutes and the solvent evaporated. The residue was purified by chromatography, eluting with a gradient (0-10%) of MeOH/EtOAc, to give 122 (0.59 g, 88%) as a white solid, mp (MeOH) 171-174 °C; IR N 3445, 3329, 3266, 1717, 1609, 1549, 1491, 1375, 1248 cm^"1; Η NMR [(CD₃)₂SO] δ 9.37 (s, 1 H, OCONH), 7.28 (s, 1 H, H 4'), 7.19 (br d, J= 9.1 Hz, 2 H, H 3, H 5), 6.61 (d, J= 9.1 Hz, 2 H, H 2, H 6), 5.23 (s, 2 H, CH₂O), 4.71 (t, J= 5.4 Hz, 2 H, 2 x OH), 3.96 (s, 3 H, NCH₃), 3.51 (dd, J= 6.4, 5.9 Hz, 4 H, 2 x CH₂O), 3.34 (dd, J= 6.2, 5.9 Hz, 4 H, 2 x CH₂N); ¹³C NMR [(CD₃)₂SO] δ 152.8, 146.0, 144.2, 133.6, 128.6, 127.1, 120.3 (2), 111.4 (2), 59.7, 58.2 (2), 53.4 (2), 34.2; MS (FAB⁺) m/z 380 (MH⁺, 10%), 348 (5); HRMS (FAB⁺) m/z calc. for C₁₆H₂₂N₅O₆ (MH⁺) 380.1570, found 380.1579; Anal. (C₁₆H₂₁N₅O₆) C, H, N.

(l-Methyl-2-nitro-lH-imidazol-5-yl)methyl 4-[bis(2- chloroethyl)amino]phenylcarbamate (123). Methanesulfonyl chloride (191 μL, 2.47 mmol) was added dropwise to a stirred solution of diol 122 (312 mg, 0.82 mmol) in pyridine (10 mL) at 5 °C and the solution stiπed at 20 °C for 1 h. The solvent was evaporated and the residue partitioned between DCM (100 mL) and water (100 mL). The aqueous fraction was washed with DCM (2 x 50 mL), the combined organic extracts dried, and the solvent evaporated. The residue was dissolved in DMF (10 mL), LiCl (210 mg, 4.9 mmol) added and the mixture stirred at 80 °C for 3 h. The solvent was evaporated and the residue partitioned between EtOAc (100 mL) and water (100 mL). The aqueous fraction was extracted with EtOAc (2 x 50 mL), the combined extracts dried, and the solvent evaporated. The residue was purified by chromatography, eluting with 50% EtOAc/light petroleum, to give 123 (227 mg, 66%) as a white solid, mp (MeOH) 156-157 °C; IR N 3408, 3246, 1725, 1531, 1354, 1221 cm ¹; 'H NMR [(CD₃)₂SO] δ 9.49 (s, 1 H, OCONH), 7.26-7.29 (m, 3 H, H 4', H 3, H 5), 6.70 (d, J= 9.1 Hz, 2 H, H 2, H 6), 5.24 (s, 2 H, CH₂O), 3.96 (s, 3 H, NCH₃), 3.64-3.70 (m, 8 H, 2 x CH₂N, 2 CH₂C1); ¹³C NMR [(CD₃)₂SO] δ 152.8, 146.0, 142.3, 133.5, 128.7, 128.6, 120.3 (2), 112.3 (2), 54.9, 52.2 (2), 41.1 (2), 34.1. Anal. (C₁₆H₁₉Cl₂N₅O₄) C, H, N, Cl.

Example 5C. Preparartion of (l-methyl-2-nitro-lH-imidazol-5-yl)methyI 1- (chloromethyl)-3-[(5,6,7-trimethoxy-lH-indol-l-yl)carbonyI]-2,3-dihydro-lH- benzo[e]indol-5-ylcarbamate (124). A solution of triphosgene (14.5 mg, 49 μmol) in DCM (2 mL) was added dropwise to a stirred solution of amine 1 [G. J. Atwell, W. R. Wilson, W. A. Denny, Bioorg. Med. Chem. Lett., 1997, 7, 1483] (58 mg, 124 μmol) and Et₃N (39 mL, 280 μmol) in DCM (10 mL) and stirred at 20 °C for 2 h. A solution of alcohol 115 ( 24 mg, 154 μmol) in DCM (2 mL) was added, followed by nBu₂Sn(OAc)₂ (2 drops) and the solution stirred at 20 °C for 48 h. The solvent was evaporated and the residue purified by chromatography, eluting with 40% EtOAc/light petroleum, to give 124 (55 mg, 68%) as a tan powder, mp (EtOAc) 202-204 °C; Η NMR δ 9.49 (br s, 1 H, indole- NH), 8.81 (br s, 1 H, H 4), d, J= 8.5 Hz, 1 H, H 6), 7.78 (d, J= 8.3 Hz, 1 H, H 9), 7.57 (m, 1 H, H 8), 7.43 (m, 1 H, H 7), 7.25 (s, 1 H, H 4"), 7.21 (br s, 1 H, OCONH), 7.00 (d, J= 1.6 Hz, 1 H H 3'), 6.87 (s, 1 H, H 4'), 5.31 (d, J= 13.6 Hz, 1 H, CH-O), 5.25 (d, J= 13.6 Hz, 1 H, CH₂O), 4.80 (dd, J= 10.5, 1.6 Hz, 1 H, H 2), 4.65 (dd, J= 10.5, 8.7 Hz, 1 H, H 2), 4.13- 4.20 (m, 1 H, H 1), 4.11 (s, 3 H, OCH₃), 4.01 (br s, 3 H, NCH₃), 3.94-3.98 (m, 4 H, CH₂C1, OCH₃), 3.92 (s, 3 H, OCH₃), 3.47 (dd, J= 10.8, 10.8 Hz, 1 H, CH₂C1); ¹³C NMR δ 160.4 (CO), 153.5 (OCONH), 150.2 (C 5'), 146.4 (C 2"), 141.6 (C 3a), 140.7 (C 6'), 138.9 (C 7'), 133.3 (C 5), 132.1 (C 5"), 129.8 (C 4"), 129.7 (C 9a), 129.5 (C 2'), 127.6 (C 8), 125.7 (C 7a'), 125.1 (C 7, C 5a), 123.6 (C 3a'), 123.2 (C 9), 122.3 (C 6, C 9b), 113.0 (C 4), 106.6 (C 3'), 97.6 (C 4'), 61.5 (OCH₃), 61.2 (OCH₃), 56.3 (OCH₃), 55.8 (CH₂O), 54.9 (C 2), 45.8 (CH₂C1), 43.4 (C 1), 34.3 (NCH₃); MS (FAB⁺) m/z 649 (MH⁺, 2%); HRMS (FAB⁺) calc. for C₃₁H₃₀ ³⁵C1N₆O₈ (MH⁺) m/z 649.1814, found 649.1767; calc. for C₃₁H₃₀ ³⁷C1N₆O₈ (MH⁺) m/z 651.1784, found 651.1819; Anal (C₃₁H₂₉ClN₆O₈.'/₂H₂O) C, H, N.

Alternative preparation of (l-methyl-2-nitro-lH-imidazol-5-yl)methyl 1- (chloromethyl)-3-[(5,6,7-trimethoxy-lH-indol-l-yl)carbonyl]-2,3-dihydro-lH- benzo[e]indol-5-ylcarbamate (124). A solution of alcohol 115 (17 mg, 0.11 mmol) in DCM (2 mL) was added dropwise to a stiπed solution of triphosgene (12 mg, 0.04 mmol) and pyridine (9 μL, 0.11 mmol) in DCM (2 mL) at 20 °C. The mixture was stiπed at 20 °C for 2 h, the solvent evaporated and the residue dissolved in THF (5 mL). A solution of amine 1 [G. J. Atwell, W. R. Wilson, W. A. Denny, Bioorg. Med. Chem. Lett., 1997, 7, 1483] (50 mg, 0.11 mmol) in THF ( 5 mL) was added and the solution stiπed at 20 °C for 16 h. The mixture was partitioned between EtOAc (50 mL) and sat. aq. KHCO₃ solution, the organic fraction dried, and the solvent evaporated. The residue was purified by chromatography, eluting with a gradient (50-100%) of EtOAc/light petroleum to give 124 (23 mg, 33%o) as a tan solid, mp 200-205 °C (dec); spectroscopically identical with an authentic sample prepared above.

Example 5D. Preparation of (l-methyl-2-nitro-lH-imidazol-5-yl)methyl doxorubicin carbamate (125). A solution of (l-methyl-2-nitro-lH-imidazol-5-yl)methyl 4-nitrophenyl carbonate (116) (33 mg, 104 μmol) in DMF (2 mL) was added dropwise to a stirred solution of doxorubicin (13) (46 mg, 86 μmol) and Et₃N (15 μL, 104 μmol) in DMF (5 mL) at 20 °C and the solution stiπed for 16 h. The solvent was evaporated and the residue purified by chromatography, eluting with a gradient (0-5%) of MeOΗ/DCM, to give 125 (44 mg, 70%) as a red solid, mp (DCM) 162-166 °C; 'Η NMR [(CD₃)₂SO] δ 13.96 (s, 1 Η, 6-OΗ), 13.21 (s, 1 H, 11-OH), 7.82-7.87 (m, 2 H, H 1, H 3), 7.58 (dd, J= 7.5, 2.1 Hz, 1 H, H 2), 7.18 (s, 1 H, H 4"), 7.02 (d, J= 7.9 Hz, 1 H, OCONH), 5.42 (s, 1 H, 9-OH), 5.21 (d, J = 2.6 Hz, 1 H, H 1 '), 5.07 (s, 2 H, CH₂O), 4.86-4.91 (m, 2 H, H 7, 14-OH), 4.73 (d, J= 5.9 Hz, 1 H, 4-OH), 4.58 (d, J= 5.9 Hz, 2 H, H 14), 4.13-4.17 (m, 1 H, H 5'), 3.96 (s, 3 H, 4- OCH₃), 3.88 (s, 3 H, NCH₃), 3.66-3.74 (m, 1 H, H 3'), 341-346 (m, 1 H, H 4'), 2.97 (d, J = 18.3 Hz, 1 H, H 10), 2.87 (d, J= 18.3 Hz, 1 H, H 10), 2.21 (d, J= 14.0 Hz, 1 H, H 8), 2.17 (dd, J= 14.0, 5.4 Hz, 1 H, H 8), 1.84 (dt, J= 12.8, 3.5 Hz, 1 H, H 2'), 1.57 (dd, J = 12.8, 3.8 Hz, 1 H, H 2'), 1.12 (d, J= 6.4 Hz, 3 H, H 6');¹³C NMR [(CD₃)₂SO] δ 213.7 (C 13), 186.3 (C 5), 186.2 (C 12), 160.7 (C 4), 156.0 (6), 154.6 (C 11), 154.4 (OCONH), 145.8 (C 2"), 136.1 (C 2), 135.4 (C 12a), 134.5 (C 6a), 134.0 (C 10a), 133.8 (C 5"), 128.3 (C 4"), 119.8 (C 4a), 119.6 (C 1), 118.9 (C 3), 110.6 (C 5a), 110.5 (C 11a), 100.3 (C 1 '), 74.9 (C 9), 69.8 (C 7), 67.8 (C 4'), 66.6 (C 5'), 63.7 (C 14), 56.5 (4-OCH₃), 54.7 (CH₂O), 47.3 (C 3'), 38.4 (C 8), 34.1 (NCH₃), 32.0 (C 10), 29.7 (C 2'), 17.0 (C 6'); MS (FAB⁺) m/z 727 (MH⁺, 0.2%); HRMS (FAB⁺) calc. for C₃₃H₃₄N₄O₁₅ (MH⁺) m/z 727.2099, found 727.2075; Anal (C₃₃H₃₄N₄O₁₅.¹/₂H₂O) C, H, N.

Example 5E. Preparation of 4-({[(l-methyl-2-nitro-lH-imidazol-5- yl)methoxy]carbonyl}amino)benzyl doxorubicin carbamate (129). (l-Methyl-2-nitro-lH-imidazoI-5-yl)methyl 4-({[tert- butyI(dimethyl)siIyl]oxy}methyl)phenylcarbamate (126). Et₃N (0.26 mL, 1.86 mmol) was added to a stiπed suspension of ( 1 -methyl-2-nitro- lH-imidazol-5-yl)methyl 4- nitrophenyl carbonate (116) (0.50 g, 1.55 mmol), 4-({[tert- butyl(dimethyl)silyl]oxy}methyl)aniline (9) (0.40 g, 1.71 mmol), ΗOBT (0.21 g, 1.55 mmol), and 4 A molecular sieves (500 mg) in TΗF (80 mL) and the mixture stirred at 20 °C for 16 h. The solvent was evaporated and the residue partitioned between EtOAc (100 mL) and water (100 mL). The organic fraction was washed with 1 M ΗC1 (2 x 40 mL), water (100 mL), brine (50 mL), dried, and the solvent evaporated. The residue was purified by chromatography, eluting with 40% EtOAc/light petroleum, to give 126 (0.43 mg, 66%) as a white solid, mp (EtOAc/light petroleum) 131-132 °C; "Η NMR δ 7.33 (br d, J= 8.8 Ηz, 2 Η, Η 3, Η 5), 7.27 (d, J= 8.8 Ηz, 2 Η, Η 2, Η 6), 7.23 (s, 1 Η, Η 4'), 6.83 (br s, 1 Η, OCONΗ), 5.22 (s, 2 Η, CΗ₂O), 4.69 (s, 2 H, CH₂O), 4.05 (s, 3 H, NCH₃), 0.93 (s, 9 H,

SiC(CH₃)₃), 0.09 (s, 6 H, Si(CH₃)₂); ¹³C NMR δ 152.3 (OCONH), 146.1 (C 2'), 137.4 (C 1), 135.8 (C 4), 132.5 (C 5'), 129.6 (C 4'), 126.9 (C 2, C 6), 118.8 (C 3, C 5), 64.5 (CH₂O), 55.4 (CH₂O), 34.3 (NCH₃), 25.9 (SiC(CH₃)₃), 18.4 (SiC(CH₃)₃), -5.3 (Si(CH₃)₂); Anal. (C₁₉H₂₈N₄O₅Si) C, H, N.

(l-MethyI-2-nitro-lH-imidazoI-5-yl)methyl 4-(hydroxymethyl)phenylcarbamate (127). 1 M HCI (2 mL, 2 mmol) was added to a stiπed solution of silyl ether 126 (0.39 g, 0.93 mmol) in MeOH (10 mL) and stiπed at 20 °C for 1 h. The solution was poured into brine (50 mL) and extracted with EtOAc (3 50 mL). The combined organic fraction was washed with water (50 mL), dried, and the solvent evaporated. The residue was purified by chromatography, eluting with a gradient (50-100%) EtOAc/light petroleum, to give 127 (247 mg, 87%) as a pale yellow solid, mp (EtOAc) 180-181 °C; Η NMR [(CD₃)₂SO] δ 9.77 (br s, 1 H, OCONH), 7.40 (d, J- 8.5 Hz, 2 H, H 3, H 5), 7.31 (s, 1 H, H 4'), 7.22 (d, J = 8.5 Hz, 2 H, H 2, H 6), 5.27 (s, 2 H, CH₂O), 5.08 (t, J- 5.6 Hz, 1 H, OH), 4.42 (d, J= 5.6 Hz, 2 H, CH₂O), 3.97 (s, 3 H, NCH₃); ¹³C NMR [(CD₃)₂SO] δ 152.6 (OCONH), 146.0 (C 2'), 137.2 (C 1), 136.8 (C 4), 133.3 (C 5'), 128.7 (C 4'), 127.0 (C 2, C 6), 118.0 (C 3, C 5), 62.4 (CH₂O), 55.0 (CH₂O), 34.2 (NCH₃); Anal. (C_!3H₁₄N₄O₅) C, H, N.

4-({[(l-methyl-2-nitro-lH-imidazoI-5-yl)methoxy]carbonyl}amino)benzyI 4- nitrophenyl carbonate (128). A solution of 4-nitrophenylchloroformate (216 mg, 1.07 mmol) in THF (5 mL) was added dropwise to a stiπed solution of alcohol 127 (219 mg, 0.72 mmol) in THF (40 mL) and the solution stirred at 20 °C for 96 h. The solvent was evaporated and the residue partitioned between EtOAc (100 ml) and water (100 mL). The organic fraction was washed with water (2 50 mL), brine (50 mL), dried, and the solvent evaporated. The residue was purified by chromatography, eluting with 50% EtOAc/light petroleum, to give 128 (62 mg, 18%) as a white solid; Η NMR [(CD₃)₂SO] δ 9.96 (s, 1 H, OCONH), 8.31 (ddd J= 9.2, 3.3, 2.2 Hz, 2 H, H 3", H 5"), 7.56 (ddd, J= 9.2, 3.3, 2.2 Hz, 2 H, H 2", H 6"), 7.51 (d, J= 8.6 Hz, 2 H, H 3, H 5), 7.40 (d, J= 8.6 Hz, 2 H, H 2, H 6), 7.31 (s, 1 H, H 4'), 5.33 (s, 2 H, CH₂O), 5.24 (s, 2 H, CH₂O), 3.98 (s, 3 H, NCH₃); ¹³C NMR [(CD₃)₂SO] δ 155.2 (OCO2), 152.6 (OCONH), 151.9 (C 1"), 145.1 (C 2'), 139.2 (C 1), 133.2 (C 4), 129.6 (C 3", C 5"), 128.8 (C 4'), 128.7 (C 5'), 125.6 (C 2, C 6), 122.2 (C 2", C 6"), 118.8 (C 2, C 6), 70.2 (CH₂O), 55.2 (CH₂O), 34.2 (NCH₃); MS (FAB⁺) m/z 472 (MH\1%), 443 (0.5); HRMS (FAB⁺) calc. for C₂₀H₁₈N₅O₉ (MH⁺) m/z 472.1105, found 472.1106.

4-({[(l-MethyI-2-nitro-lH-imidazol-5-yl)methoxy]carbonyl}amino)benzyl doxorubicin carbamate (129). A solution of carbonate 128 (81 mg, 172 μmol) in DMF (2 mL) was added dropwise to a stirred solution of doxorubicin (45 mg, 86 μmol) and Et₃N (15 μL, 103 μmol) in DMF (5 mL) at 20 °C and the solution stiπed for 24 h. The solvent was evaporated and the residue purified by chromatography, eluting with 5% MeOH/DCM, to give 129) (57 mg, 75%) as a red solid, mp (DCM) 160-162 °C; 'H NMR [(CD₃)₂SO] δ 13.99 (s, 1 H, 6-OH), 13.24 (s, 1 H, 11-OH), 9.82 (s, 1 H, OCONH), 7.84-7.89 (m, 2 H, H 1, H 2), 7.60-7.63 (m, 1 H, H 3), 7.40 (d, J= 8.3 Hz, 2 H, H 3", H 5"), 7.29 (s, 1 H, H 4"'), 7.23 (d, J= 8.3 Hz, 2 H, H 2", H 6"), 6.81 (d, J= 8.0 Hz, 1 H, OCONH), 5.43 (s, 1 H, H 7), 5.25 (s, 2 H, CH₂O), 5.21 (d, J= 2.9 Hz, 1 H, H 1 '), 4.89-4.91 (m, 1 H, 9-OH), 4.87 (s, 2 H, CH₂O), 4.84 (dd, J= 6.3, 5.8 Hz, 1 H, 14-OH), 4.69 (d, J= 5.7 Hz, 1 H, 4-OH), 4.58 (d, J = 6.0 Hz, 2 H, H 14), 4.13-4.17 (m, 1 H, H 5'), 3.97 (s, 3 H, OCH₃), 3.95 (s, 3 H, NCH₃), 3.68-3.75 (m, 1 H, H 3'), 343-346 (m, 1 H, H 4'), 2.99 (d, J= 18.3 Hz, 1 H, H 10), 2.91 (d, J= 18.3 Hz, 1 H, H 10), 2.21 (br d, J= 14.1 Hz, 1 H, H 8), 2.10 (dd, J= 14.1 Hz, 1 H, H 8), 1.84 (dt, J= 12.9, 3.6 Hz, 1 H, H 2'), 1.47 (dd, J= 12.9, 3.8 Hz, 1 H, H 2'), 1.13 (d, J = 6.5 Hz, 3 H, H 6'); ¹³C NMR [(CD₃)₂SO] δ 213.7 (C 13), 186.4 (C 5), 186.3 (C 12), 160.7 (C 4), 156.0 (C 6), 155.2 (C 11), 154.4 (OCONH), 152.6 (OCONH), 146.0 (C 2'"), 138.2 (C 4"), 136.1 (C 2), 135.4 (C 12a), 134.6 (C 6a), 134.0 (C 10a), 13.2 (C 5'"), 131.2 (C 1"), 128.7 (C 4'"), 128.6 (C 2", C 6"), 119.9 (C 4a), 119.6 (C 1), 118.9 (C 3), 118.0 (C 3", C 5"), 110.7 (C 5a), 110.5 (C 1 la), 100.2 (C 1 '), 74.9 (C 9), 69.8 (C 7), 67.9 (C 4'), 66.6 (C 5'), 64.8 (C 14), 63.6 (CH₂O), 56.5 (OCH₃), 55.1 (CH₂O), 47.0 (C 3'), 36.5 (C 8), 34.1 (NCH₃), 32.0 (C 10), 29.8 (C 2'), 16.9 (C 6'); MS (FAB⁺) m/z 876 (MH⁺, 0.2%); Anal. (C₄₁H_4]N₅O₁₇.H₂O) C, H, N.

Example 5F. Preparation of (l-methyl-4-nitro-lH-imidazol-5-yl)methyl 1- (chloromethyl)-3-[(5,6,7-trimethoxy-lH-indol-l-yl)carbonyI]-2,3-dihydro-lH- benzo [e] indol-5-ylcarbamate (132) .

(l-Methyl-4-nitro-lH-imidazol-5-yl)methanol (131). Ozone was bubled through a solution of l-methyl-4-nitro-5-[(E)-2-phenylethenyl]-lH-imidazole (130) [ D. C. Baker, S. R. Putt, Η. D. Η. Showalter, J. Heterocyclic Chem., 1983, 30, 629-634.] (1.0 g, 4.36 mmol) in DCM/MeOΗ (1:1, 120 mL) at -78 ° C until a blue colour persisted. The solution was warmed to -40 °C with a nitrogen purge to remove excess ozone. A solution of NaBΗ₄ (165 mg, 4.36 mmol) in ΕtOH (10 mL) was added dropwise over 15 min and the mixture stiπed for 30 min. Acetic acid (0.5 mL) was added and the solvent evaporated. The residue was partitioned between water (50 mL) and light petroleum (50 mL). The aqueous fraction was evaporated and the residue triturated with hot acetone (60 mL). The mixture was filtered and the solution concentrated to give 131 (523 mg, 78%) as a tan powder, mp (acetone) 135-137 °C; 'H NMR δ 7.78 (s, 1 H, H 2), 5.48 (t, J= 5.6 Hz, 1 H, OH), 4.85 (d, J= 5.6 Hz, 2 H, CH₂O), 3.75 (s, 3 H, NCH₃); ¹³C NMR δ 143.5 (C 4), 136.8 (C 2), 133.2 (C 5), 51.4 (CH₂O), 32.5 (NCH₃); Anal. (C₅H₇N₃O₃) C, H, N.

(l-Methyl-4-nitro-lH-imidazol-5-yl)methyl l-(chloromethyl)-3-[(5,6,7-trimethoxy-lH- indol-l-yl)carbonyl]-2,3-dihydro-lH-benzo[e]indol-5-ylcarbamate (132). A solution of triphosgene (13 mg, 43 μmol) in DCM (2 mL) was added dropwise to a stiπed solution of amine 1 [G. J. Atwell, W. R. Wilson, W. A. Denny, Bioorg. Med. Chem. Lett., 1997, 7, 1483] (51 mg, 109 μmol) and Et₃N (34 μL, 246 μmol) in DCM (10 mL) and stiπed at 20 °C for 2 h. A solution of (l-methyl-4-nitro-lH-imidazol-5-yl)methanol 131 (23 mg, 147 μmol) in DCM (2 mL) was added, followed by nBu₂Sn(OAc)₂ (2 drops) and the solution stirred at 20 °C for 24 h. The solvent was evaporated and the residue purified by chromatography, eluting with EtOAc, to give 132 (40 mg, 56%) as a white powder, mp (EtOAc/light petroleum) 229-231 °C; Η NMR δ 9.48 (s, 1 Η, indole-NΗ), 8.87 (s, 1 Η, OCONΗ), 7.87 (d, J= 8.5 Ηz, 1 Η, Η 6), 7.76 (d, J= 8.3 Ηz, 1 Η, Η 9), 7.55 (ddd, J= 8.3, 7.4, 0.7 Ηz, 1 Η, Η 8), 7.44 (ddd, J= 8.5, 7.4, 0.7 Ηz, 1 Η, Η 7), 7.40 (s, 1 Η, Η 2"), 7.33 (br s, 1 Η, Η 4), 7.00 (d, J= 2.3 Ηz, 1 Η, Η 3'), 6.87 ( s, 1 Η, Η 4'), 5.61 (s, 2 Η, CΗ₂O), 4.78 (dd, J= 10.7, 1.7 Hz, 1 H, H 2), 4.65 (dd, J= 10.7, 8.7 Hz, 1 H, H 2), 4.15-4.20 (m, 1 H, H 1), 4.05-4.10 (m, 4 H, OCH₃, CH₂C1), 3.95 (s, 3 H, OCH₃), 3.92 (s, 3 H, OCH₃), 3.83 (br s, 3 H, NCH₃), 3.44 (dd, J= 10.9, 10.7 Hz, 1 H, CH₂C1); ¹³C NMR δ 160.4 (CO), 153.8 (OCONH), 150.2 (C 5'), 146.3 (C 4"), 141.5 (C 3a), 140.6 (C 6'), 138.8 (C 7% 136.3 (C 2"), 133.4 (C 5), 129.7 (C 9a), 129.5 (C 2'), 127.6 (C 8), 126.9 (C 5"), 125.7 (C 7a'), 125.2 (C 7), 125.2 (C 5a), 123.6 (C 3a*), 123.1 (C 9), 122.3 (C 6), 121.9 (C 9b), 112.5 (C 4), 106.6 (C 3'), 97.7 (C 4'), 61.5 (OCH₃), 61.1 (OCH₃), 56.3 (OCH₃), 54.9 (C 2), 54.4 (CH₂O), 45.8 (CH₂C1), 43.4 (C 1), 33.2 (NCH₃); MS (FAB⁺) m/z 651 (MH⁺, 1%), 649 (MH\ 2); HRMS (FAB⁺) calc. for C₃₁H₃₀ ³⁵C1N₆O₈ (MH⁺) m/z 649.1814, found 649.1818; calc. for C₃₁H₃₀ ³⁷C1N₆O₈ (MH⁺) m/z 651.1784, found 651.1805; Anal. (C₃₁H₂₉ClN₆O₈) C, H, N.

Example 5G. Preparation of (l-methyl-5-nitro-l -T-imidazol-2-yI)methyl bis(2- chloroethyl)carbamate (135).

(l-Methyl-5-nitro-lH-imidazol-2-yl)methanol (133). A mixture of l-methyl-5-nitro-lH- imidazole [C.E. Hazeldine, F.L. Pyman, J. Winchester. J Chem. Soc. 1924, 1431] (1.0 g, 7.9 mmol) and paraformaldehyde (1.4 g, 15.7 mmol) in DMSO (10 mL) was heated in a sealed tube at 100 °C for 24 h. The mixture was cooled to 20 °C, EtOH (50 mL) was added, and the suspension was filtered. The filtrate was concentrated and the residue was purified by chromatography on alumina, eluting with a gradient of MeOH/CHCl₃ (0-10%), to give 133 (0.71 g, 57%) as a white solid, mp (CHC1₃) 1 16-118 °C (lit. [C. Rufer, H. J. Kessler, E. Schroder. J. Med. Chem. 1971, 14, 94] mp 1 1 1 °C); 'H NMR [(CD₃)₂SO] δ 7.90 (s, 1 H, H 4), 5.62 (t, J= 5.8 Hz, 1 H, OH), 4.62 (d, J= 5.8 Hz, 2 H, CH₂O), 3.99 (s, 3 H, NCH₃); ¹³C NMR [(CD₃)₂SO] δ 151.8, 138.8, 130.9, 56.1, 32.9.

(l-Methyl-5-nitro-lH-imidazol-2-yI)methyI 4-nitrophenyl carbonate (134). A solution of 4-nitrophenyl chloroformate (1.48 g, 7.4 mmol) in THF (8 mL) was added slowly to a stiπed solution of alcohol 133 (1.10 g, 7.0 mmol) and pyridine (0.62 mL, 7.7 mmol) in THF (50 mL) at 20 °C under N₂. The mixture was stirred at 20 °C for 16 h, then partitioned between EtOAc/H₂O. The organic fraction was washed with saturated aqueous NaHCO₃ (50 mL), and the solvent evaporated to give 134 (2.04g, 94%) as a tan solid, mp (EtOAc/light petroleum) 168-171 °C; Η NMR [(CD₃)₂SO] δ 8.33 (ddd, J= 9.1, 3.2, 2.2 Hz, 2 H, H 3, H 5), 8.11 (s, 1 H, H 4'), 7.59 (ddd, J= 9.1, 3.2, 2.2 Hz, 2 H, H 2, H 6), 5.48 (s, 2 H, CH₂O), 3.97 (s, 3 H, NCH₃); ¹³C [(CD₃)₂SO] δ 155.0, 151.3, 145.9, 145.2, 139.5, 131.6, 125.3 (2), 122.4 (2), 61.7, 33.5.

(l-Methyl-5-nitro-lH-imidazol-2-yl)methyl bis(2-chloroethyl)carbamate (135). A solution of carbonate 134 (2.0 g, 6.5 mmol) in pyridine (5 mL) was added to a stiπed solution of NN-bis-(2-chloroethyl)amine hydrochloride (1.5 g, 8.4 mmol) in pyridine (30 mL) at 0 °C. The solution was stirred at 20 °C for 16 h, then solvent was evaporated and the residue was partitioned between DCM (100 mL) and 10% aqueous citric acid (100 mL). The organic fraction was dried, the solvent evaporated, and the residue was purified by chromatography, eluting with 50% EtOAc/light petroleum, to give 135 (2.0 g, 95%) as an oil; Η ΝMR δ 7.99 (s, 1 H, H 4') 5.27 (s, 2 H, CH₂O), 4.03 (s, 3 H, ΝCH₃), 3.60-3.71 (m, 8 H, 2 x CH₂N, 2 CH₂C1); ¹³C NMR δ 154.8, 146.9, 139.6, 132.2, 58.7, 51.1 (2), 41.8 (2), 39.7; HRMS calc. for C₁₀H₁₄C1₂N₄O₄(M⁺) m/z 324.1392; found 324.1381.

Example 5H. Preparation of (l-methyl-5-nitro-lH-imidazol-2-yl)methyl 4-[bis(2- chIoroethyl)amino]phenylcarbamate (137). Diphosgene (85mL, 0.7 mmol) was added dropwise to a stiπed solution of (l-methyl-5-nitro-lH-imidazol-2-yl)methanol (133) (0.2 g, 1.27 mmol) and Et₃N (98 mL, 0.7 mmol) in TΗF (10 mL) at 5 °C. The suspension was stirred at 5 °C for 30 min and a mixture of N'N¹-bis(2-chloroethyl)-l,4-benzenediamine hydrochloride (136) (J. L. Everett, W. C. J. Ross. J. Chem. Soc. 1949, 1972] (0.38 g, 1.40 mmol) and Et₃N (195 mL, 1.40 mmol) in THF (4 mL) was added dropwise to the above suspension. The mixture was stirred at 20 °C for 4 h, the solvent evaporated and the residue purified by chromatography, eluting with 50% EtOAc/light petroleum, to give 137 (0.19 g, 36%), mp (CHCypet. ether) 164-164.5 °C; IR n 3250, 3185, 3127, 1723, 1603, 1547,

1516, 1381 cm ¹; Η NMR ([(CD₃)₂SO] δ 9.57 (br s, 1 H, OCONH), 8.08 (s, 1 H, H 4'), 7.27 (br d, J= 8.0 Hz, 2 H, H 3, H 5), 6.70 (d, J= 9.1 Hz, 2 H, H 2, H 6), 5.26 (s, 2 H, CH₂O), 3.95 (s, 3 H, NCH₃), 3.65-3.72 (m, 8 H, 2 x CH₂N, 2 x CH₂C1); ¹³C NMR [(CD₃)₂SO] δ 152.7, 148.0, 142.3, 139.3, 131.7, 128.7, 120.3 (2), 112.3 (2), 57.4, 52.2 (2), 41.1 (2), 33.4; MS (DEI) m/z 415 (M⁺, 1%), 366 (2), 316 (2), 258 (20), 211 (30), 209 (100); HRMS (DEI) m/z calc. for C₁₆H₁₉ ³⁵Cl₂N₅O₄ (M⁺) 415.0814, found 415.0808; calc. for C₁₆H₁₉ ³⁵Cl³⁷ClN₅O₄ (M⁺) 417.0785, found 417.0781; calc. for C_I6H,₉ ³⁷Cl₂N₅O₄ (M⁺) 419.0755, found 419.0769; Anal. (C₁₆H₁₉Cl₂N₅O₄) C, H, N.

Example 51. Preparation of (l-methyl-5-nitro-lH-imidazol-2-yl)methyl 1- (chloromethyl)-3-[(5,6,7-trimethoxy-lH-indol-2-yl)carbonyl]-2,3-dihydro-lH- benzo[e]indoI-5-ylcarbamate (138). A solution of triphosgene (12 mg, 41 μmol) in DCM (2 mL) was added dropwise to a stirred solution of amine 1 [G. J. Atwell, W. R. Wilson, W. A. Denny, Bioorg. Med. Chem. Lett., 1997, 7, 1483] (48 mg, 103 μmol) and Et₃N (32 μL, 231 μmol) in DCM (10 mL) and stirred at 20 °C for 2 h. A solution of (l-methyl-5-nitro- lH-imidazol-2-yl)methanol (133) (20 mg, 127 μmol) in DCM (2 mL) was added, followed by nBu₂Sn(OAc)₂ (2 drops) and the solution stirred at 20 °C for 24 h. The solvent was evaporated and the residue purified by chromatography, eluting with 40%) EtOAc/DCM, to give 138 (23 mg, 34%) as a tan powder mp (EtOAc) 169-170 °C; Η NMR δ 9.47 (s, 1 Η, indole-NΗ), 8.85 (s, 1 Η, OCONΗ), 7.98 (s, 1 Η, Η 4"), 7.86 (d, J = 8.5 Ηz, 1 Η, Η 6), 7.77 (d, J= 8.3 Ηz, 1 Η, Η 9), 7.57 (br dd, J= 8.3, 7.4 Ηz, 1 Η, Η 8), 7.44 (ddd, J= 8.5, 7.4, 0.7 Ηz, 1 Η, Η 7), 7.37 (br s, 1 Η, Η 4), 6.99 (d, J= 2.3 Ηz, 1 Η, Η 3'), 6.87 ( s, 1 Η, Η 4'), 5.38 (d, J= 13.4 Ηz, 1 Η, CΗ₂O), 5.34 (d, J= 13.4 Hz, 1 H, CH₂O), 4.79 (dd, J= 10.7, 1.6 Hz, 1 H, H 2), 4.65 (dd, J= 10.7, 8.7 Hz, 1 H, H 2), 4.15-4.19 (m, 1 H, H 1), 4.09 (s, 3 H, OCH₃), 4.02 (br s, 3 H, NCH₃), 3.95 (s, 3 H, OCH₃), 3.92-3.94 (m, 4 H, OCH₃, CH₂C1), 3.45 (dd, J = 10.9, 10.7 Hz, 1 H, CH₂C1); ¹³C NMR δ 160.4 (CO), 153.4 (OCONH), 150.2 (C 5'), 146.9 (C 5"), 141.6 (C 3a), 140.7 (C 6'), 139.6 (C 2"), 138.9 (C 7'), 133.3 (C 5), 132.1 (C 4"), 129.7 (C 9a), 129.6 (C 2'), 127.6 (C 8), 125.7 (C 7a'), 125.2 (C 7 and C 5a), 123.6 (C 3a'), 123.2 (C 9), 122.3 (C 6), 122.2 (C 9b), 1 12.8 (C 4), 106.6 (C 3'), 97.7 (C 4'), 61.5 (OCH₃), 61.2 (OCH₃), 58.4 (CH₂O), 56.3 (OCH₃), 54.9 (C 2), 45.8 (CH₂C1), 43.4 (C 1), 33.8 (NCH₃); MS (FAB⁺) m/z 649 (MH⁺, 3%), 651 (1.5); HRMS (FAB⁺) calc. for C₃₁H₃₀ ³⁵C1N₆O₈ (MH⁺) m/z 649.1814, found 649.1797; calc. for C₃₁H₃₀ ³⁷C1N₆O₈ (MH⁺) m/z 651.1784, found 651.1802; Anal. (C_3IH₂₉ClN₆O₈) C, H, N.

Example 5J. Preparation of 4-({[(l-methyl-5-nitro-lH-imidazol-2- yl)methoxy]carbonyl}amino)benzyl doxorubicin carbamate (142). l-Methyl-5-nitro-lH-imidazol-2-yl 4-({[tert- butyl(dimethyI)silyl]oxy}methyl)phenylcarbamate (139). Et₃N (1.10 mL, 7.87 mmol) was added to a stirred suspension of (l-methyl-5-nitro-lH-imidazol-2-yl)methyl 4- nitrophenyl carbonate (134) (2.31 g, 7.17 mmol), 4-({[tert- butyl(dimethyl)silyl]oxy}methyl)aniline (120) (1.79 g, 7.87 mmol), ΗOBT (0.97 g, 7.17 mmol), and 4 A molecular sieves (2.5 g) in TΗF (100 mL) and the mixture stirred at 20 °C for 48 h. The solvent was evaporated and the residue partitioned between EtOAc ( 100 mL) and water (100 mL). The organic fraction was washed with 1 M ΗC1 (2 x 40 mL), water (100 mL), brine (50 mL), dried, and the solvent evaporated. The residue was purified by chromatography, eluting with 50% EtOAc/light petroleum, to give 139 (2.57 g, 85%) as a white solid, mp (EtOAc/light petroleum) 145-146 °C; Η NMR δ 7.99 (s, 1 Η, Η 4'), 7.32 (br d, J= 8.1 Ηz, 2 Η, Η 3, Η 5), 7.27 (d, J= 8.1 Ηz, 2 Η, Η 2, Η 6), 6.96 (br s, 1 Η, OCONΗ), 5.30 (s, 2 Η, CΗ₂O), 4.69 (s, 2 H, CH₂O), 4.05 (s, 3 H, NCH₃), 0.93 (s, 9 H, SiC(CH₃)₃), 0.09 (s, 6 H, Si(CH₃)₂); ¹³C NMR δ 152.3 (OCONH), 147.0 (C 5'), 139.6 (C 2'), 137.4 (C 1), 135.8 (C 4'), 129.6 (C 4), 126.9 (C 2, C 6), 118.8 (C 3, C 5), 64.5 (CH₂O), 58.0 (CH₂O), 33.7 (NCH₃), 25.9 (SiC(CH₃)₃), 18.4 (SiC(CH₃)₃), -5.3 (Si(CH₃)₂); Anal. (C₁₉H₂₈N₄O₅Si) C, H, N.

(l-Methyl-5-nitro-lH-imidazol-2-yl)methyI 4-(hydroxymethyI)phenyIcarbamate (140).

1 M HCI (16 mL, 16 mmol) was added to a stiπed solution of silyl ether 139 (1.36 g, 3.22 mmol) in MeOH (50 mL) and stiπed at 20 °C for 1 h. The solution was poured into brine (50 mL) and extracted with EtOAc (3 x 50 mL). The combined organic fraction was washed with water (50 mL), dried, and the solvent evaporated. The residue was crystallized from EtOAc/light petroleum, to give 140 (0.86g, 47%) as a white solid, mp (EtOAc/light petroleum) 181-183 °C; Η NMR [(CD₃)₂SO] δ 9.85 (br s, 1 H, OCONH), 8.09 (s, 1 H, H 4'), 7.40 (d, J= 8.5 Hz, 2 H, H 3, H 5), 7.22 (d, J= 8.5 Hz, 2 H, H 2, H 6), 5.29 (s, 2 H, CH₂O), 4.42 (s, 2 H, CH₂O), 3.96 (s, 3 H, NCH₃), 3.79 (br s, 1 H, OH); ¹³C NMR [(CD₃)₂SO] δ 152.5 (OCONH), 147.8 (C 5'), 139.3 (C 2'), 137.4 (C 1), 136.8 (C 4), 131.7 (C 2, C 6), 127.0 (C 3, C 5), 118.0 (C 4), 62.4 (CH₂O), 57.5 (CH₂O), 33.4 (NCH₃); Anal. (C₁₃H₁₄N₄O₅) C, H, N.

4-({[(l-Methyl-5-nitro-lH-imidazol-2-yl)methoxy]carbonyl}amino)benzyl 4- nitrophenyl carbonate (141). A solution of 4-nitrophenylchloroformate (0.72 g, 3.55 mmol) in THF (10 mL) was added dropwise to a stiπed solution of alcohol 140 (0.73 g, 2.37 mmol) and Et₃N (0.66 mL, 4.73 mmol) in THF (40 mL) and the solution stirred at 20 °C for 16 h. The solvent was evaporated and the residue was purified by chromatography, eluting with 20% EtOAc/DCM, to give 141 (0.71 g, 63%) as a white solid; 'H NMR [(CD₃)₂SO] δ 10.02 (s, 1 H, OCONH), 8.31 (ddd J= 9.1, 3.3, 2.1 Hz, 2 H, H 3, H 5), 8.08 (s, 1 H, H 4"), 7.57 (ddd, J= 9.1, 3.3, 2.1 Hz, 2 H, H 2, H 6), 7.51 (d, J= 8.5 Hz, 2 H, H 3', H 5'), 7.40 (d, J= 8.5 Hz, 2 H, H 2', H 6'), 5.32 (s, 2 H, CH₂O), 4.70 (s, 2 H, CH₂O), 3.97 (s, 3 H, NCH₃); MS (FAB⁺) m/z 472 (MH⁺,1.5%); HRMS (FAB⁺) calc. for C₂₀H₁₈N₅O₉ (MH⁺) m/z 472.1105, found 472.1108.

4-({[(l-Methyl-5-nitro-lH-imidazol-2-yl)methoxy]carbonyl}amino)benzyl doxorubicin carbamate (142). A solution of carbonate 141 (61 mg, 129 μmol) in DMF (2 mL) was added dropwise to a stirred solution of doxorubicin (13) (45 mg, 86 μmol) and Et₃N (18 μL, 129 μmol) in DMF (5 mL) at 20 °C and the solution stirred for 24 h. The solvent was evaporated and the residue purified by chromatography, eluting with 5% MeOH/DCM, to give 142 (50 mg, 66%) as a red solid, mp (DCM) 170-173 °C; 'H NMR [(CD₃)₂SO] δ 14.00 (s, 1 H, 6-OH), 13.24 (s, 1 H, 11-OH), 9.91 (s, 1 H, OCONH), 8.07 (s, 1 H, H 4'"), 7.86-7.90 (m, 2 H, H 1, H 2), 7.60-7.63 (m, 1 H, H 3), 7.40 (d, J= 8.4 Hz, 2 H, H 3", H 5"), 7.23 (d, J= 8.4 Hz, 2 H, H 2", H 6"), 6.81 (d, J= 8.0 Hz, 1 H, OCONH), 5.43 (s, 1 H, H 7), 5.27 (s, 2 H, CH₂O), 5.21 (d, J= 2.9 Hz, 1 H, H 1'), 4.92-4.95 (m, 1 H, 9-OH), 4.87 (s, 2 H, CH₂O), 4.84 (dd, J= 6.3, 5.9 Hz, 1 H, 14-OH), 4.69 (d, J= 5.7 Hz, 1 H, 4-OH), 4.58 (d, J= 6.0 Hz, 2 H, H 14), 4.12-4.18 (m, 1 H, H 5'), 3.97 (s, 3 H, OCH₃), 3.95 (s, 3 H, NCH₃), 3.68-3.75 (m, 1 H, H 3'), 343-346 (m, 1 H, H 4'), 2.98 (d, J= 18.3 Hz, 1 H, H 10), 2.91 (d, J= 18.3 Hz, 1 H, H 10), 2.20 (br d, J= 14.1 Hz, 1 H, H 8), 2.11 (dd, J = 14.1 Hz, 1 H, H 8), 1.84 (dt, J= 12.9, 3.7 Hz, 1 H, H 2'), 1.47 (dd, J= 12.9, 4.0 Hz, 1 H, H 2'), 1.12 (d, J = 6.5 Hz, 3 H, H 6'); ¹³C NMR [(CD₃)₂SO] δ 213.7 (C 13), 186.4 (C 5), 186.3 (C 12), 160.7 (C 4), 156.0 (C 6), 155.2 (C 11), 154.4 (OCONH), 152.4 (OCONH), 147.8 (C 5'"), 139.3 (C 2'"), 138.2 (C 4"), 136.1 (C 2), 135.4 (C 12a), 134.6 (C 6a), 134.0 (C 10a), 131.7 (C 4'"), 131.2 (C 1"), 128.6 (C 2", C 6"), 119.9 (C 4a), 1 19.6 (C 1), 118.9 (C 3), 118.0 (C 3", C 5"), 110.7 (C 5a), 110.5 (C 1 la), 100.2 (C 1 '), 74.9 (C 9), 69.8 (C 7), 67.9 (C 4'), 66.6 (C 5'), 64.8 (C 14), 63.6 (CH₂O), 57.6 (CH₂O), 56.5 (OCH₃), 47.0 (C 3'), 36.5 (C 8), 33.4 (NCH₃), 32.0 (C 10), 29.7 (C 2'), 16.9 (C 6'); MS (FAB⁺) m/z 876 (MH⁺, 0.6%); HRMS (FAB⁺) calc. for C₄₁H₄₂N₅O₁₇(MH⁺) m/z 876.2576, found 876.2573; Anal. (C₄₁H₄₁N₅O₁₇.H₂O) C, H, N.

Example 5K. Preparation of [l-(2-hydroxyethyl)-5-nitro-lH-imidazol-2-yl]methyl 1- (chIoromethyl)-3-[(5,6,7-trimethoxy-lH-indol-2-yl)carbonyl]-2,3-dihydro-lH- benzo [e] indol-5-yIcarbamate (148) . 2-{5-Nitro-2-[(E)-2-phenylethenyl]-lH-imidazol-l-yl}ethanol (144). A solution of Na (2.0 g, 87.6 mmol) in dry MeOH (30 mL) was added in one portion to a stirred solution of metronidazole (143) (10.0 g, 58.4 mmol) and benzaldehyde (7.1 mL, 70 mmol) in DMSO (30 mL) at 20 °C. The mixture was stood at 20 °C for 24 h. Water (80 mL) was added and the resulting solid filtered. The solid was dissolved in EtOAc (100 mL) dried, and the solvent evaporated. The residue was purified by chromatography, eluted with 50% EtOAc/light petroleum, to give 144 (4.0 g, 26%) as a yellow powder, mp 155 °C (lit mp 156-157 °C [ W. J. Ross, W. B. Jamieson, and M. C. McCowen, J. Med. Chem. 1972, 15, 1035-1039]); 'H NMR δ 8.06 (s, 1 H, H 4'), 7.83 (d, J= 15.8 Hz, 1 H, CH=), 7.52-7.58 (m, 2 H, H 2", H 6"), 7.33-7.38 (m, 3 H, H 3", H 4", H 5"), 7.05 (d, J= 15.8 Hz, 1 H, CH=), 4.64 (dd, J= 5.1, 5.0 Hz, 2 H, H 1), 4.07 (dd, J= 5.1, 5.0 Hz, 2 H, H 2), 242 (br s, 1 H, OH); ^, C NMR δ 150.9 (C 5'), 140.0 (CH=), 138.5 (C 2'), 135.3 (C 1"), 134.6 (C 4'), 129.7 (C 4"), 128.9 (C 3", C 5"), 127.6 (C 2", C 6"); 112.1 (CH=), 61.8 (C 1), 47.7 (C 2).

/ert-Butyl(dimethyl)silyl 2-{5-nitro-2-[(E)-2-phenylethenyl]-lH-imidazol-l-yl}ethyl ether (145). TBDMS triflate (2.7 mL, 11.75 mmol) was added dropwise to a stirred solution of alcohol 144 (2.77 g, 10.7 mmol) and pyridine (1.3 mL, 16.0 mmol) in DCM (100 mL) at -5 °C and the solution stiπed at 20 °C for 16 h. The reaction was quenched with MeOH (5 mL) and poured in sat. aq. KHCO₃ (100 mL). The mixture was extracted with DCM (3 x 50 mL), the combined organic fraction dried and the solvent evaporated. The residue was purified by chromatography, eluting with 20% EtOAc/light petroleum, to give 145 (4.00 g, 100%) as a yellow solid, mp (EtOAc/light petroleum) 99-100.5 °C; 'H NMR δ 8.13 (s, 1 H, H 4'), 7.87 (d, J= 15.8 Hz, 1 H, CH=), 7.57 (d, J- 6.8 Hz, 2 H, H 2", H 6"), 7.34-741 (m, 3 H, H 3", H 4", H 5"), 7.06 (d, J= 15.8 Hz, 1 H, CH=), 4.62 (dd, J- 5.0, 4.8 Hz, 2 H, H 1), 4.00 (dd, J= 5.0, 4.8 Hz, 2 H, H 2), 0.77 (s, 9 H, SiC(CH₃)₃), 0.10 (s, 6 H, Si(CH₃)₂); ¹³C NMR δ 151.2 (C 5'), 139.3 (CH=), 138.4 (C 2'), 135.5 (C 1'), 134.8 (C 4'), 129.6 (C 4"), 128.9 (C 3", C 5"), 127.5 (C 2", C 6"), 112.9 (CH=), 62.3 (C 1), 47.8 (C 2), 25.7 (SiC(CH₃)₃), 18.1 (SiC(CH₃)₃), -5.8 (Si(CH₃)₂); Anal. (C₁₉H₂₇N₃O₃Si) C, H, N.

[l-(2-{[tert-Butyl(dimethyl)silyl]oxy}ethyl)-5-nitro-lH-imidazol-2-yl]methanol (146). Ozone was bubbled into a solution of imidazole 145 (1.3 g, 3.48 mmol) in DCM/MeOH (1:1, 120 mL) at -78 °C until a blue colour persisted. The solution was warmed to ^40 °C with a N₂ purge to remove excess ozone. A solution of NaBH₄ (132 mg, 3.48 mmol) in EtOH (10 mL) was added dropwise over 15 min and the mixture stirred for 30 min. The mixture was treated with acetic acid (0.5 mL), stirred for 10 min and the solvent evaporated. The residue was partitioned between EtOAc (100 mL) and water (100 mL). The organic fraction was washed with water (50 mL), brine (25 mL), dried, and the solvent evaporated. The residue was purified by chromatography, eluting with 50% EtOAc/light petroleum, to give 146 (0.92 g, 88%) as a white solid, mp 104-105 °C; Η NMR δ 7.97 (s, 1 H, H 4), 4.79 (s, 2 H, CH₂O), 4.62 (t, J= 4.8 Hz, 2 H, CH₂O), 3.97 (t, J= 4.8 Hz, 2 H, CH₂N), 3.80 (br s, 1 H, OH), 0.81 (s, 9 H, SiC(CH₃)₃), 0.10 (s, 6 H, Si(CH₃)₂); ¹ C NMR δ 157.2 (C 2), 138.8 (C 5), 132.3 (C 4), 62.0 (CH₂O), 57.2 (CH₂O), 48.3 (CH₂N), 25.7 (SiC(CH₃)₃), 18.2 (SiC(CH₃)₃), -5.8 (Si(CH₃)₂); Anal. (C₁₂H₂₃N₃O₄Si) C, H, N.

[l-(2-{[tert-Butyl(dimethyl)silyl]oxy}ethyl)-5-nitro-lH-imidazol-2-yl]methyl l- (chloromethyl)-3-[(5,6,7-trimethoxy-lH-indol-2-yl)carbonyI]-2,3-dihydro-lH- benzo[e]indol-5-ylcarbamate (147). A solution of triphosgene (25 mg, 84 μmol) in DCM (3 mL) was added dropwise to a stirred solution of amine 1 [G. J. Atwell, W. R. Wilson, W. A. Denny, Bioorg. Med. Chem. Lett., 1997, 7, 1483] (112 mg, 240 μmol) and Et₃N (67 μL, 481 μmol) in DCM (10 mL) and stirred at 20 °C for 2 h. A solution of alcohol 146 (78 mg, 264 μmol) in DCM (3 mL) was added, followed by nBu₂Sn(OAc)₂ (2 drops) and the solution stiπed at 20 °C for 24 h. The solvent was evaporated and the residue purified by chromatography, eluting with 20% EtOAc/DCM, to give 147 (93 mg, 49%) as a colourless oil, Η NMR δ 9.41 (s, 1 H, indole-NH), 8.88 (s, 1 H, OCONH), 8.06 (s, 1 H, H 4"), 7.87 (d, J= 8.5 Hz, 1 H, H 6), 7.79 (d, J= 8.3 Hz, 1 H, H 9), 7.57 (dd, J= 8.3, 7.5 Hz, 1 H, H 8), 7.46 (dd, J = 8.5, 7.5 Hz, 1 H, H 7), 7.17 (br s, 1 H, H 4), 7.00 (d, J = 2.2 Hz, 1 H, H 3'), 6.88 ( s, 1 H, H 4'), 5.44 (d, J= 13.5 Hz, 1 H, CH₂O), 5.39 (d, J= 13.5 Hz, 1 H, CH₂O), 4.81 (dd, J= 10.7, 1.5 Hz, 1 H, H 2), 4.65-4.74 (m, 3 H, H 2, CH₂N), 4.16-4.22 (m, 1 H, H 1), 4.10 (s, 3 H, OCH₃), 3.95-3.99 (m, 4 H, CH-C1, OCH₃), 3.89-3.93 (m, 5 H, OCH₃, CH₂N), 3.48 (t, J= 10.9 Hz, 1 H, CH₂C1) ), 0.81 (s, 9 H, SiC(CH₃)₃), -0.08 (s, 6 H, Si(CH₃)₂); MS (FAB⁺) m/z 795 (MH⁺, 12%), 793 (25); HRMS (FAB⁺) calc. for C_3gH₄₆ ³⁵ClN₆O₉Si (MH⁺) m/z 793.2784, found 793.2762; calc. for C₃₈H₄₆ ³⁷ClN₆O₉Si (MH⁺) m/z 795.2755, found 795.2751.

[l-(2-hydroxyethyl)-5-nitro-lH-imidazol-2-yl]methyl l-(chloromethyl)-3-[(5,6,7- trimethoxy-lH-indol-2-yl)carbonyl]-2,3-dihydro-lH-benzo[e]indol-5-ylcarbamate (148). IM HCI (0.23 mL, 230 μmol) was added to a stirred solution of silyl ether 147 (91 mg, 115 μmol) in MeOH (5 mL) and the solution stiπed at 20 °C for 4 h. The solvent was evaporated and the residue partitioned between EtOAc (40 mL) and water (40 mL). The organic fraction was washed with water (25 mL), brine (20 mL), dried, and the solvent evaporated. The residue was purified by chromatography, eluting with a gradient (0- 10%MeOH/40%EtOAc/DCM), to give 148 as a white solid, mp (EtOAc/light petroleum) 148-150 (dec); 'H NMR δ [(CD₃)₂SO] 11.45 (s, 1 H, indole-NH), 9.92 (s, 1 H, OCONH), 8.45 (s, 1 H, H 4), 8.16 (s, 1 H, H 4"), 8.06 (d, J= 8.5 Hz, 1 H, H 6), 7.97 (d, J= 8.3 Hz, 1 H, H 9), 7.58 (ddd, J= 8.3, 7.2, 0.8 Hz, 1 H, H 8), 7.46 (ddd, J- 8.5, 7.2, 0.8 Hz, 1 H, H 7), 7.09 (d, J= 2.0 Hz, 1 H, H 3'), 6.97 ( s, 1 H, H 4'), 5.37 (s, 2 H, CH₂O), 5.12 (t, J= 5.4 Hz, 1 H, OH), 4.80 (dd, J= 10.7, 9.4 Hz, 1 H, H 2), 4.56-4.60 (m, 3 H, H 2, CH₂O), 4.32- 4.38 (m, 1 H, H 1), 4.06 (dd, J= 11.1, 3.2 Hz, 1 H, CH₂C1), 3.91-3.95 (m, 4 H, OCH₃, CH₂C1), 3.83 (s, 3 H, OCH₃), 3.81 (s, 3 H, OCH₃), 3.70-3.75 (m, 2 H, CH₂N); ¹³C NMR δ [(CD₃)₂SO] 160.1 (CO), 154.0 (OCONH), 149.1 (C 5'), 148.7 (C 5"), 141.4 (C 3a), 139.9 (C 6'), 139.0 (C 7'), 138.9 (C 2"), 134.1 (C 5), 132.5 (C 4"), 130.7 (C 9a), 129.4 (C 2'), 127.1 (C 8), 125.4 (C 7a'), 125.3 (C 5a), 124.3 (C 7), 123.8 (C 9), 123.3 (C 6), 123.1 (C 3a'), 122.2 (C 9b), 113.2 (C 4), 106.2 (C 3'), 98.0 (C 4'), 61.0 (OCH₃), 60.9 (OCH₃), 59.7 (CH₂O), 58.1 (CH₂O), 55.9 (OCH₃), 54.9 (C 2), 48.2 (CH₂N), 47.8 (CH₂C1), 41.1 (C 1); MS (FAB⁺) m/z 681 (MH\ 5%), 679 (MH\ 12%); HRMS (FAB⁺) calc. for C₃₂H₃₂ ³⁵ClN₆O₉ (MH⁺) m/z 679.1919, found 679.1797; calc. for C₃₂H₃₂ ³⁷C1N₆0₉ (MH⁺) m/z 681.1890, found 681.1892; Anal. (C₃₂H₃₁ClN₆O₉) C, H, N.

Example 5L. Preparation of (l-methyI-5-nitro-l/7-imidazol-4-yl)methyl 1- (chloromethyl)-3-[(5,6,7-trimethoxy-lH-indol-l-yl)carbonyl]-2,3-dihydro-lH- benzo[e]indol-5-ylcarbamate (150). A solution of triphosgene (21 mg, 70 μmol) in DCM (2 mL) was added dropwise to a stirred solution of amine 1 [G. J. Atwell, W. R. Wilson, W. A. Denny, Bioorg. Med. Chem. Lett., 1997, 7, 1483] (93 mg, 200 μmol) and Et₃N (55 μL, 400 μmol) in DCM (10 mL) and stiπed at 20 °C for 2 h. A solution of (l-methyl-5-nitro- lH-imidazol-4-yl)methanol 149 [ D. C. Baker, S.R. Putt, Η. D. Η. Showalter, J.

Heterocyclic Chem., 1983, 20, 629-634.] (37 mg, 240 μmol) in DCM (3 mL) was added, followed by nBu₂Sn(OAc)₂ (2 drops) and the solution stirred at 20 °C for 24 h. The solvent was evaporated and the residue purified by chromatography, eluting with 5% MeOΗ/EtOAc, to give 150 (40 mg, 56%) as a tan powder, mp (EtOAc) 219-220 °C; 'Η NMR [(CD₃)₂SO] δ 11.47 (s, 1 Η, indole-NΗ), 9.80 (s, 1 Η, OCONΗ), 8.54 (br s, 1 Η, Η 4), 8.08-8.11 (m, 2 Η, Η 6, Η 2"), 7.97 (d, J= 8.4 Ηz, 1 Η, Η 9), 7.57 (ddd, J= 8.4, 7.2, 0.7 Ηz, 1 Η, Η 8), 7.45 (ddd, J= 8.5, 7.2, 0.7 Ηz, 1 Η, Η 7), 7.09 (d, J= 2.0 Ηz, 1 Η, Η 3'), 6.97 ( s, 1 Η, Η 4'), 5.40 (s, 2 Η, CΗ₂O), 4.79 (dd, J= 10.8, 1.4 Hz, 1 H, H 2), 4.52 (dd, J= 11.0, 1.9 Hz, 1 H, H 2), 4.31-4.36 (m, 1 H, H 1), 4.07 (dd, .7= 11.1, 3.0 Hz, 1 H, CH-C1), 3.89-3.95 (m, 7 H, OCH₃, CH₂C1, NCH₃), 3.83 (s, 3 H, OCH₃), 3.81 (s, 3 H, OCH₃); ¹³C NMR [(CD₃)₂SO] δ 160.1 (CO), 154.3 (OCONH), 154.2 (C 5"), 149.1 (C 5'), 141.4 (C 2"), 141.2 (C 3a), 139.9 (C 6'), 139.0 (C 7'), 135.1 (C 4"), 134.4 (C 5), 130.8 (C 9a), 129.4 (C 2'), 127.0 (C 8), 125.5 (C 5a), 125.4 (C 7a'), 124.2 (C 7) 123.9 (C 9), 123.2 (C 6), 123.1 (C 3a'), 122.0 (C 9b), 113.1 (C 4), 106.2 (C 3'), 98.0 (C 4'), 61.0 (OCH₃), 60.9 (OCH₃), 59.6 (CH₂O), 55.9 (OCH₃), 54.8 (C 2), 47.5 (CH₂C1), 41.1 (C 1), 35.1 (NCH₃); MS (FAB⁺) m/z 651 (MH⁺, 2%), 649 (MH\ 8); HRMS (FAB⁺) calc. for C₃₁H₃₀ ³⁵C1N₆O₈ (MH⁺) m/z 649.1814, found 649.1802; calc. for C₃₁H₃₀ ³⁷C1N₆O₈ (MH⁺) m/z 651.1784, found 651.1761; Anal. (C_3IH₂₉ClN₆O₈) C, H, N.

Example 6A. Preparation of (5-nitro-2-furyl)methyl 4-[bis(2- chloroethyl)amino]phenylcarbamate (154).

(5-Nitro-2-furyl)methyl 4-nitrophenyl carbonate (152). A solution of 4-nitrophenyl chloroformate (4.17 g, 20.7 mmol) in dry THF (50 mL) was added slowly to a stirred solution of (5-nitrofuran-2-yl)methanol (151) [J. M. Berry, C. Y. Watson, W. J. D. Whish, and M. D. Threadgill. J. Chem. Soc. Perkin Trans. 1, 1997, 1147] (2.69 g, 18.7 mmol) and pyridine (1.67 mL, 20.7 mmol) in THF (100 mL) at 20 °C under N₂. The mixture was stiπed at 20 °C for 16 h, then partitioned between EtOAc (100 mL) and H₂O (100 mL). The organic layer was washed with saturated aqueous NaHCO₃ (50 mL), dried, and the solvent evaporated. The residue was purified by chromatography, eluting with a gradient (25-50%) of EtOAc/light petroleum to give 152 (4.79 g, 83%) as a white powder, mp (EtOAc/light petroleum) 93-94 °C; IR N 1775, 1526, 1352, 1215 cm^"1; 'H NMR [(CD₃)₂SO] δ 8.34 (ddd, J= 9.2, 3.2, 2.1 Hz, 2 H, H 3, H 5), 7.72 (d, J= 3.8 Hz, 1 H, H 4'), 7.61 (ddd, J= 9.2, 3.2, 2.1 Hz, 2 H, H 2, H 6), 7.07 (d, J= 3.8 Hz, 1 H, H 3'), 5.43 (s, 2 H, CH₂O); ^,3C [(CD₃)₂SO] δ 155.0, 154.1, 151.8, 151.5, 145.2, 125.4(2), 122.5(2), 115.1, 113.3, 61.5; Anal. (C₁₂H₈N₂O₈) C, H, N.

(5-Nitro-2-furyl)methyl 4-[bis(2-hydroxyethyl)amino]phenylcarbamate (153). A solution of carbonate 152 (1.00 g, 3.24 mmol), N¹N¹-bis(2-hydroxyethyl)-l,4- benzenediamine (57) (3.24 mmol), and pyridine (260 μL, 3.24 mmol) in THF (80 mL) was stirred at 20 °C for 16 h. The solvent was evaporated and the residue purified by chromatography, eluting with a gradient (0-10%) of MeOH/EtOAc, to give 153 (0.74 g, 63%) as an oil; Η ΝMR [(CD₃)₂SO] δ 9.44 (s, 1 H, OCOΝH), 7.68 (d, J= 3.7 Hz, 1 H, H 4*), 7.20 (br d, J= 9.1 Hz, 2 H, H2, H 6), 6.93 (d, J= 3.7 Hz, 1 H, H 3'), 6.62 (d, J= 9.1 Hz, 2 H, H 3, H 5), 5.19 (s, 2 H, CH₂O), 4.71 (t, J= 5.4 Hz, 2 H, 2 x OH), 348-3.54 (m, 4 H, 2 x CH₂O), 3.33-3.38 (m, 4 H, 2 x CH₂Ν); ¹³C NMR [(CD₃)₂SO] δ 154.0, 152.7, 151.5, 144.2, 127.0, 120.4 (2), 113.8, 113.6, 111.4 (2), 58.1 (2), 57.1, 53.4 (2); MS (DEI) m/z 365 (M⁺, 15%), 334 (70), 222 (20), 196 (40), 191 (100); HRMS (DEI) calc. for C₁₆H₁₉N₃O₇ (M⁺) m/z 365.1223, found 365.1218.

(5-Nitro-2-furyl)methyl 4-[bis(2-chloroethyl)amino]phenylcarbamate (154). Methanesulphonyl chloride (460 μL, 6.0 mmol) was added dropwise to a stirred solution of diol 153 (0.73 g, 2.0 mmol) in pyridine (30 mL) at 5 °C and the solution stirred at 20 °C for 2 h. The solvent was evaporated and the residue partitioned between DCM (100 mL) and water (100 mL). The aqueous fraction was washed with DCM (2 x 50 mL), the combined organic extracts dried, and the solvent evaporated. The residue was dissolved in DMF (20 mL), LiCl (0.51 g, 12.0 mmol) added and the mixture stiπed at 80 °C for 3 h. The solvent was evaporated and the residue partitioned between EtOAc (150 mL) and water (150 mL). The aqueous fraction was extracted with EtOAc (2 80 mL), the combined extracts dried, and the solvent evaporated. The residue was purified by chromatography, eluting with 50% EtOAc/light petroleum, to give 154 (0.62 g, 77%) as an oil; 'H NMR δ 9.57 (br s, 1 H, OCONH), 7.69 (d, J= 3.7 Hz, 1 H, H 4'), 7.28 (br d, J= 9.1 Hz, 2 H, H 2, H 6), 6.95 (d, J = 3.7 Hz, 1 H, H 3'), 6.70 (d, J= 9.1 Hz, 2 H, H 3, H 5), 5.21 (s, 2 H, CH₂O), 3.63-3.72 (m, 8 H, 2 x CH₂N, 2 x CH₂C1); ¹³C NMR (CDC1₃) δ 153.9, 152.7, 151.5, 1 142.3, 128.7, 120.3 (2), 113.8, 113.6, 112.3 (2), 57.2, 52.3 (2), 41.1 (2); MS (DEI) m/z 401 (M⁺, 50%), 403 (30), 405 (10) 354 (40), 352 (100); HRMS (DEI) calc. for C₁₆H₁₇ ³⁵Cl₂N₃O₅ (M⁺) m/z 401.0545, found 401.0546; calc. for C₁₆H₁₇ ³⁵Cl³⁷ClN₃O₅ (M⁺) m/z 403.0516, found 403.0521; calc. for C₁₆H₁₇ ³⁷Cl₂N₃O₅ (M⁺) m/z 405.0486, found 405.0498.

Example 6B. Preparation of (5-nitro-2-furyl)methyl l-(chloromethyI)-3-[(5,6,7- trimethoxy-lH-indol-l-yl)carbonyl]-2,3-dihydro-lH-benzo[e]indol-5-ylcarbamate (155). A solution of triphosgene (14 mg, 48 μmol) in DCM (2 mL) was added dropwise to a stirred solution of amine 1 [G. J. Atwell, W. R. Wilson, W. A. Denny, Bioorg. Med. Chem. Lett., 1997, 7, 1483] (57 mg, 122 μmol) and Et₃N (38 μL, 275 μmol) in DCM (10 mL) and stiπed at 20 °C for 2 h. A solution of (5-nitrofuran-2-yl)methanol (151) [J. M. Berry, C. Y. Watson, W. J. D. Whish, and M. D. Threadgill. J. Chem. Soc. Perkin Trans. I, 1997, 1147] (24 mg, 165 μmol) in DCM (2 mL) was added, followed by nBu₂Sn(OAc)₂ ( 2 drops) and the solution stirred at 20 °C for 24 h. The solvent was evaporated and the residue purified by chromatography, eluting with 30% EtOAc/DCM, to give 155 (65 mg, 84%) as a white solid, mp (EtOAc/light petroleum) 185-187 °C; 'H NMR δ 11.46 (s, 1 H, indole-NH), 9.92 (s, 1 H, OCONH), 8.54 (s, 1 H, H 4), 8.04 (d, J= 8.5 Hz, 1 H, H 6), 7.98 (d, J= 8.3 Hz, 1 H, H 9), 7.72 (d, J= 3.8 Hz, 1 H, H 4"), 7.58 (ddd, J= 8.3, 7.2, 0.7 Hz, 1 H, H 8), 7.45 (ddd, J= 8.5, 7.2, 0.7 Hz, 1 H, H 7), 7.09 (d, J= 2.1 Hz, 1 H, H 3'), 6.98-7.00 (m, 2 H, H 4', H 3"), 5.30 (s, 2 H, CH₂O), 4.80 (dd, J = 10.8, 9.5 Hz, 1 H, H 2), 4.53 (dd, J = 10.8, 1.9 Hz, 1 H, H 2), 4.32-4.37 (m, 1 H, H 1), 4.07 (dd, J= 11.1, 3.0 Hz, 1 H, CH₂C1), 3.91-3.96 (m, 4 H, OCH₃, CH₂C1), 3.83 (s, 3 H, OCH₃), 3.80 (s, 3 H, OCH₃); ¹³C NMR δ 160.1 (CO), 153.9 (OCONH), 153.8 (C 5"), 151.1 (C 2"), 149.2 (C 5'), 141.4 (C 3a), 139.8 (C 6'), 139.0 (C 7'), 134.0 (C 5), 130.7 (C 9a), 129.4 (C 2'), 127.1 (C 8), 125.4 (C 5a), 125.3 (C 7a'), 124.3 (C 7), 123.7 (C 9), 123.3 (C 6), 123.1 (C 3a), 122.2 (C 9b), 113.9 (C 3"), 113.6 (C 4"), 113.1 (C 4), 106.2 (C 3'), 98.0 (C 4'), 61.0 (OCH₃), 60.9 (OCH₃), 57.7 (CH₂O), 55.9 (OCH₃), 54.8 (C 2), 47.5 (CH₂C1), 41.1 (C 1); MS (FAB⁺) m/z 635 (MH⁺, 6%), 637 (MH\ 3); HRMS (FAB⁺) calcd for C₃₁H₂₈ ³⁵ClN₄O₉ (MH⁺) m/z 635.1545, found 635.1552; calcd for C₃₁H₂₈ ³⁷ClN₄O₉ (MH⁺) m/z 637.1515, found 637.1514; Anal. (C₃₁H₂₇ClN₄O₉)

Example 7A. Preparation of (5-nitro-2-thienyl)methyl 4-[bis(2- chloroethyl)amino]phenylcarbamate (159).

4-Nitrophenyl (5-nitro-2-thienyl)methyl carbonate (157). 4-Nitrophenyl chloroformate (2.58 g, 12.8 mmol) in dry THF (20 mL) was added slowly to a stirred solution of (5- nitrothien-2-yl)methanol (156) [P. J. Narcombe, R. K. Norris. Aust. J. Chem. 1979, 32, 2647] (1.85 g, 11.6 mmol) and pyridine (1.03 mL, 12.8 mmol) in THF (50 mL) at 20 °C under N₂. The mixture was stirred at 20 °C for 16 h, then partitioned between EtOAc (100 mL) and H₂O (100 mL). The organic layer was washed with saturated aqueous NaHCO₃ (50 mL), and the solvent evaporated to give 157 (1.86g, 49%), mp (EtOAc/light petroleum) 121-122 °C; IR N 1763, 1522, 1345, 1231 cm^"1; 'H NMR [(CD₃)₂SO] δ 8.33 (ddd, J= 9.2, 3.4, 2.2 Hz, 2 H, H 3', H 5'), 8.08 (d, J= 4.2 Hz, 1 H, H 4), 7.60 (ddd, J= 9.2, 3.4, 2.2 Hz, 2 H, H 2', H 6'), 74 (d, J= 4.2 Hz, 1 H, H 3), 5.56 (s, 2 H, CH₂O); ¹³C NMR [(CD₃)₂SO] δ 155.0, 151.6, 148.2, 145.2, 144.8, 129.5, 129.0, 125.4 (2), 122.6 (2), 64.4; Anal. (C₁₂H₈N₂O₇S) C, H, N.

(5-Nitro-2-thienyl)methyl 4-[bis(2-hydroxyethyI)amino]phenylcarbamate (158). A solution of 157 (0.75 g, 2.3 mmol), N¹N'-bis(2-hydroxyethyl)-l,4-benzenediamine (57) (2.5 mmol), and pyridine (206 μL, 2.5 mmol) in THF (50 mL) was stirred at 20 °C for 16 h. The solvent was evaporated and the residue purified by chromatography, eluting with EtOAc to give 158 (0.56 g, 64%), mp (EtOAc/light petroleum) 139-140.5 °C; IR Ν 3360, 3208, 1730, 1530, 1337, 1215 cm^"1; 'H ΝMR [(CD₃)₂SO] δ 9.46 (s, 1 H, OCOΝH), 8.02 (d, J= 4.2 Hz, 1 H, H 4'), 7.29 (d, J= 4.2 Hz, 1 H, H 3'), 7.21 (br d, J= 9.1 Hz, 2 H, H 2, H 6), 6.62 (d, J= 9.1 Hz, 2 H, H 3, H 5), 5.33 (s, 2 H, CH₂O), 4.72 (t, J= 5.5 Hz, 2 H, 2 OH), 349-3.56 (m, 4 H, 2 x CH₂O), 3.36 (t, J= 6.2 Hz, 4 H, 2 x CH₂Ν); ¹³C NMR [(CD₃)₂SO] δ 153.0, 150.8, 148.1, 144.3, 129.6, 127.5, 126.9, 120.5 (2), 111.4 (2), 60.1, 58.2 (2), 53.4 (2); Anal. (C₁₆H₁₉N₃O₆S) C, H; N, calc 11.0, found 10.5%.

(5-Nitro-2-thienyl)methyl 4-[bis(2-chloroethyl)amino]phenylcarbamate (159). Methane-sulphonyl chloride (260 μL, 3.4 mmol) was added dropwise to a stirred solution of diol 158 (0.43 g, 1.1 mmol) in pyridine (10 mL) at 5 °C and the solution stirred at 20 °C for 2 h. The solvent was evaporated and the residue partitioned between DCM (50 mL) and water (50 mL). The aqueous fraction was washed with DCM (2 50 mL), the combined organic extracts dried, and the solvent evaporated. The residue was dissolved in DMF (10 mL), LiCl (0.29 g, 6.8 mmol) added and the mixture stirred at 80 °C for 3 h. The solvent was evaporated and the residue partitioned between EtOAc (100 mL) and water (100 mL). The aqueous fraction was extracted with EtOAc (2 x 50 mL), the combined extracts dried, and the solvent evaporated. The residue was purified by chromatography, eluting with 50% EtOAc/light petroleum, to give 159 (0.35 g, 69%) as pale green needles, mp (EtOAc/light petroleum) 99-100 °C; IRN 3353, 1723, 1547, 1530, 1339, 1219 cm^"1; 'H NMR [(CD₃)₂SO] δ 9.58 (br s, 1 H, OCONH), 8.04 (d, J= 4.2 Hz, 1 H, H 4'), 7.28-7.30 (m, 3 H, H 3', H 3, H 5), 6.71 (d, J= 9.1 Hz, 2 H, H 2, H 6), 5.34 (s, 2 H, CH₂O), 3.65-3.72 (m, 8 H, 2 x CH₂N, 2 CH₂C1); ¹³C NMR [(CD₃)₂SO] δ 153.0, 150.8, 148.2, 142.4, 129.5, 128.6, 127.5, 120.4 (2), 112.3 (2), 60.1, 52.2 (2), 41.1 (2); Anal. (C₁₆H₁₉Cl₂N₅O₄) C, H, N, Cl.

Example 7B. Preparation of (5-nitro-2-thienyl)methyl l-(chIoromethyl)-3-[(5,6,7- trimethoxy-lH-indol-l-yl)carbonyl]-2,3-dihydro-lH-benzo[e]indol-5-ylcarbamate (160). A solution of triphosgene (15 mg, 51 μmol) in DCM (2 mL) was added dropwise to a stiπed solution of amine 1 [G. J. Atwell, W. R. Wilson, W. A. Denny, Bioorg. Med. Chem. Lett., 1997, 7, 1483] (61 mg, 131 μmol) and Et₃N (41 μL, 294 μmol) in DCM (10 mL) and stirred at 20 °C for 2 h. A solution of (5-nitro-2-thienyl)methanol (156) [P. J. Narcombe, R. K. Norris. Aust. J. Chem. 1979, 32, 2647] (28 mg, 176 μmol) in DCM (2 mL) was added, followed by nBu₂Sn(OAc)₂ (2 drops) and the solution stirred at 20 °C for 24 h. The solvent was evaporated and the residue purified by chromatography, eluting with 10% EtOAc/DCM, to give 160 (76 mg, 89%) as a white solid, mp (EtOAc/light petroleum) 218-219 °C; "H NMR [(CD₃)₂SO] δ 11.48 (br s, 1 H, indole-NH), 9.34 (br s, 1 H, OCONH), 8.55 (br s, 1 H, H 4), 8.08 (d, J= 4.1 Hz, 1 H, H 4"), 8.04 (d, J= 8.5 Hz, 1 H, H 6), 7.99 (d, J= 8.3 Hz, 1 H, H 9), 7.58 (dd, J= 8.3, 7.4 Hz, 1 H, H 8), 7.47 (dd, J= 8.5, 7.4 Hz, 1 H, H 7), 7.33 (d, J= 4.1 Hz, 1 H, H 3"), 7.10 (d, J= 1.9 Hz, 1 H, H 3'), 6.97 (s, 1 H, H 4'), 5.43 (s, 2 H, CH₂O), 4.80 (dd, J = 11.0, 9.5 Hz, 1 H, H 2), 4.54 (dd, J= 11.0, 1.8 Hz, 1 H, H 2), 4.32-4.36 (m, 1 H, H 1), 4.07 (dd, J= 11.0, 3.0 Hz, 1 H, CH₂C1), 3.92-3.96 (m, 4 H, CH₂C1, OCH₃), 3.92 (m, 3 H, OCH₃), 3.81 (s, 3 H, OCH₃); ^I3C NMR [(CD₃)₂SO] δ 160.3 (CO), 154.4 (OCONH), 151.1 (C 5"), 149.3 (C 5'), 148.2 (C 2"), 141.6 (C 3a), 140.0 (C 6'), 139.1 (C 7'), 134.1 (C 5), 130.8 (C 9a), 129.7 (C 3"), 129.6 (C 2'), 127.8 (C 4"), 127.4 (C 8), 125.6 (C 5a), 125.5 (C 7a'), 124.6 (C 7), 123.8 (C 9), 123.3 (C 6), 123.2 (C 3a'), 122.5 (C 9b), 113.5 (C 4), 106.4 (C 3'), 98.1 (C 4'), 61.2 (OCH₃), 61.0 (OCH₃), 60.8 (CH₂O), 56.0 (OCH₃), 55.0 (C 2), 47.7 (CH₂C1), 41.2 (C 1); MS (FAB⁺) m/z 653 (MH⁺, 4%), 651 (MH\ 8); HRMS (FAB⁺) calc. for C₃₁H_2g ³⁵ClN₄O₈S (MH⁺) m/z 651.1316, found 651.1311; calc. for C₃₁H₂₈ ³⁷ClN₄O₈S (MH⁺) m/z 653.1287, found 653.1307; Anal. (C₃₁H₂₇ClN₄O₈S) C, H, N.

Example 8. Preparation of (l-methyl-5-nitro-li/-pyrazol-4-yl)methyl 1-

(chloromethyl)-3-[(5,6,7-trimethoxy-lH-indol-l-yl)carbonyl]-2,3-dihydro-lH- benzo[e]indol-5-ylcarbamate (163).

(l-methyl-5-nitro-lH-pyrazoI-4-yI)methanol (162). Borane dimethylsulfide (2 M solution in THF, 4.2 mL, 8.4 mmol) was added to a solution of l-methyl-5-nitro-lH- pyrazole-4-carboxylic acid (161) [C.C. Cheng, J. Heterocyclic Chem. 1968, 5, 195-197] (1.11 g, 6.5 mmol) in TΗF (50 mL) under N₂, and the mixture stirred at reflux temperature for 80 min, then cooled. MeOΗ (5 mL), then water (5 mL), then 2 M ΗC1 (5 mL) were added, the TΗF was evaporated, and the residue was diluted with water and extracted with EtOAc (3 x 50 mL). The combined organic extract was dried, the solvent evaporated, and the residue purified by chromatography, eluting with 50% EtO Ac/petroleum ether, to give 162 (0.52 g, 51%) as a white solid, mp (benzene) 78-80 °C. 'Η NMR δ 7.58 (s, 1 Η, Η 3), 4.82 (d, J= 3.4 Ηz, 2 Η, CΗ₂O), 4.25 (s, 3 H, NCH₃), 2.39 (br s, 1 H, OH); Anal. (C₅H₇N₃O₃) C, H, N.

(l-MethyI-5-nitro-lH-pyrazol-4-yI)methyl l-(chloromethyl)-3-[(5,6,7-trimethoxy-lH- indol-l-yl)carbonyl]-2,3-dihydro-lH-benzo[e]indol-5-ylcarbamate (163). A solution of triphosgene (14.3 mg, 48 μmol) in DCM (2 mL) was added dropwise to a stiπed solution of amine 1 [G. J. Atwell, W. R. Wilson, W. A. Denny. Bioorg. Med. Chem. Lett., 1997, 7, 1483] (57 mg, 122 μmol) and Et₃N (38 μL, 275 μmol) in DCM (10 mL) and stirred at 20 °C for 2 h. A solution of alcohol 162 (26 mg, 165 μmol) in DCM (2 mL) was added, followed by nBu₂Sn(OAc)₂ (2 drops) and the solution stirred at 20 °C for 24 h. The solvent was evaporated and the residue purified by chromatography, eluting with 20 % EtOAc/DCM, to give 163 (41 mg, 52%) as a white solid, mp (EtOAc/light petroleum) 201- 202 °C; Η NMR [(CD₃)₂SO] δ 11.47 (br s, 1 H, indole-NH), 9.80 (br s, 1 H, OCONH), 8.56 (br s, 1 H, H 4), 8.06 (d, J= 8.5 Hz, 1 H, H 6), 7.98 (d, J= 8.3 Hz, 1 H, H 9), 7.74 (br s, 1 H, H 3"), 7.58 (dd, J= 8.3, 7.4 Hz, 1 H, H 8), 7.47 (dd, J= 8.5, 7.4 Hz, 1 H, H 7), 7.45 (d, J= 1.6 Hz, 1 H, H 3'), 6.98 (s, 1 H, H 4'), 5.33 (s, 2 H, CH₂O), 4.80 (dd, J= 11.0, 9.4 Hz, 1 H, H 2), 4.53 (dd, J= 11.0, 1.8 Hz, 1 H, H 2), 4.32-4.38 (m, 1 H, H 1), 4.17 (s, 3 H, NCH₃), 4.07 (dd, J= 11.0, 3.1 Hz, 1 H, CH₂C1), 3.91-3.96 (m, 4 H, OCH₃, CH₂C1), 3.82 (s, 3 H, OCH₃), 3.80 (s, 3 H, OCH₃); ¹ C NMR [(CD₃)₂SO] δ 160.2 (CO), 154.3 (OCONH), 149.1 (C 5'), 142.5 (C 5"), 141.5 (C 3a), 139.9 (C 6'), 139.0 (C 7'), 137.5 (C 3"), 134.2 (C 5), 130.7 (C 9a), 129.4 (C 2'), 127.1 (C 8), 125.4 (C 5a, C 7a), 124.3 (C 7), 123.7 (C 9), 123.3 (C 6), 123.1 (C 3a'), 122.0 (C 9b), 117.4 (C 4"), 113.0 (C 4), 106.2 (C 3'), 98.0 (C 4'), 61.0 (OCH₃), 60.9 (OCH₃), 57.2 (CH₂O), 55.9 (OCH₃), 54.8 (C 2), 47.5 (CH₂C1), 41.1 (C 1), 40.8 (NCH₃); MS (FAB⁺) m/z 650 (MH⁺, 2%), 648 (MH⁺, 5); HRMS (FAB⁺) calc. for C₃₁H₃₀ ³⁵C1N₆O₈ (MH⁺) m/z 649.1814, found 649.1803; calc. for C₃₁H₃₀ ³⁷C1N₆O₈ (MH⁺) m/z 651.1784, found 651.1796; Anal. (C₃₁H₂₉ClN₆O₈) C, H, N.

Example 9A. Preparation of ethyl 4-({[({l-(chloromethyl)-3-[(5,6,7-trimethoxy-lH- indol-l-yl)carbonyl]-2,3-dihydro-lH-benzo[e]indol-5-yI}amino)carbonyl]oxy}methyI)- l-methyl-5-nitro-lH-pyrroIe-2-carboxylate (167).

Ethyl 4-formyl-l-methyl-5-nitro-l//-pyrrole-2-carboxylate (165). Dimethyl sulfate (0.31 mL, 3.2 mmol) was added to a mixture of ethyl 4-formyl-5-nitro-lH-pyπole-2- carboxylate (164) [P. Fornari, M. Farmer, C. Fournier, Bull. Soc. Chim. Fr. 1972, 283-291] (0.57 g, 2.7 mmol) and K₂CO₃ (0.56 g, 4.0 mmol) in DMSO (4 mL) and the brown suspension was stirred at 20 °C for 1 h. The mixture was diluted with water (50 mL), acidified with ΗC1 (2 N), and extracted with EtOAc (2 x 50 mL). The combined extract was dried, the solvent evaporated. The residue was chromatograped, eluting with 10%EtOAc/light petroleum, to give 165 (0.53 g, 86%) as a pale green solid, mp (benzene/light petroleum) 59-60.5 °C; 'Η NMR δ 10.32 (s, 1 Η, CΗO), 7.42 (s, 1 Η, Η 3), 4.37 (q, J= 7.1 Ηz, 2 Η, CΗ₂), 4.33 (s, 3 H, NCH₃), 1.39 (t, J= 7.1 Hz, 3 H, CH₃); Anal. (C₉H₁₀N₂O₅) C, H, N.

Ethyl 4-(hydroxymethyl)-l-methyI-5-nitro-lH-pyrrole-2-carboxylate (166). NaBH₄ (0.33 g, 8.7 mmol) was added in portions to a solution of aldehyde 165 (3.96 g, 17.5 mmol) in EtOH (100 mL) and the mixture was stiπed at 20 °C for 20 min. Water (5 mL) was slowly added, the EtOH was evaporated, and the residue was diluted with aq. NaCl and extracted with EtOAc (2 ' 50 mL). The combined extract was washed with aq. NaCl (50 mL), dried, and the solvent evaporated. The residue was recystallized to give 166 (1.40 g, 35%) as white needles, mp (benzene) 95.5-96.5 °C; 'H NMR δ 7.01 (s, 1 H, H 3), 4.80 (br s, 2 H, CH₂O), 4.36 (q, J= 7.1 Hz, 2 H, CH₂), 4.31 (s, 3 H, NCH₃), 2.49 (br s, 1 H, OH), 1.38 (t, J= 7.1 Hz, 3 H, CH₃); Anal. (C₉H₁₂N₂O₅) C, H, N. The mother liquor was evaporated and purified by chromatography 10% EtOAc/light petroleum to give more 166 (1.46 g, 37%).

Ethyl 4-({[({l-(chloromethyl)-3-[(5,6,7-trimethoxy-lH-indol-l-yl)carbonyl]-2,3- dihydro-lH-benzo[e]indol-5-yl}amino)carbonyl]oxy}methyl)-l-methyl-5-nitro-lH- pyrrole-2-carboxylate (167). A solution of triphosgene (13.8 mg, 46 μmol) in DCM (2 mL) was added dropwise to a stiπed solution of amine 1 [G. J. Atwell, W. R. Wilson, W. A. Denny, Bioorg. Med. Chem. Lett., 1997, 7, 1483] (55 mg, 118 μmol) and Et₃N (37 μL, 265 μmol) in DCM ( 10 mL) and stirred at 20 ° C for 2 h. A solution of ethyl 4-

(hydroxymethyl)-l-methyl-5-nitro-lH-pyrrole-2-carboxylate (166) (36 mg, 159 μmol) in DCM (2 mL) was added, followed by nBu₂Sn(OAc)₂ (2 drops) and the solution stiπed at 20 °C for 24 h. The solvent was evaporated and the residue purified by chromatography, eluting with 40% EtOAc/DCM, to give 167 (26 mg, 31%) as a white solid, mp (EtOAc/light petroleum) 248-250 °C; Η NMR [(CD₃)₂SO] δ 1145 (s, 1 Η, indole-NΗ), 9.86 (s, 1 Η, OCONΗ), 8.56 (br s, 1 Η, Η 4"), 8.09 (d, J= 8.5 Ηz, 1 Η, Η 6"), 7.99 (d, J= 8.3 Ηz, 1 Η, Η 9"), 7.59 (dd, J= 8.3, 7.7 Ηz, 1 Η, Η 8"), 748 (dd, J= 8.5, 7.7 Ηz, 1 Η, Η 7"), 7.10 (d, J= 2.0 Ηz, 1 Η, Η 3'"), 7.06 (br s, 1 Η, Η 3), 6.97 (s, 1 Η, Η 4'"), 5.38 (s, 2 Η, CΗ₂O), 4.80 (dd, J= 11.0, 9.6 Hz, 1 H, H 2"), 4.53 (dd, J= 11.0, 2.0 Hz, 1 H, H 2"), 4.35- 4.40 (m, 1 H, H 1"), 4.29 (q, J= 7.1 Hz, 2 H, H 1 '), 4.19 (s, 3 H, NCH₃), 4.07 (dd, J= 11.0, 3.0 Hz, 1 H, CH₂C1), 3.92-3.96 (m, 4 H, CH₂C1, OCH₃), 3.83 (m, 3 H, OCH₃), 3.81 (s, 3 H, OCH₃), 1.31 (t, J= 7.1 Hz, 3 H, H 2'); ¹³C NMR [(CD₃)₂SO] δ 160.2 (CO), 159.4 (CO₂), 154.3 (OCONH), 149.1 (C 5'"), 141.5 (C 3a"), 139.9 (C 6'"), 139.0 (C 7'"), 137.1 (C 5), 134.2 (C 5"), 133.9 (C 2), 130.7 (C 9a"), 129.5 (C 2'"), 127.1 (C 8"), 125.6 (C 5a"), 125.5 (C 4), 125.4 (C 7a'"), 124.3 (C 7"), 123.7 (C 9"), 123.3 (C 6"), 123.1 (C 3a'"), 122.1 (C 9b"), 114.6 (C 3), 113.0 (C 4"), 106.2 (C 3'"), 98.0 (C 4'"), 61.2 (C 1 '), 61.0 (OCH₃), 60.9 (OCH₃), 59.6 (CH₂O), 55.9 (OCH₃), 54.9 (C 2"), 47.5 (CH₂C1), 41.1 (C 1"), 35.2 (NCH₃), 14.0 (C 2'); MS (FAB⁺) m/z 722 (MH⁺, 0.3%), 720 (MH\ 0.6); HRMS (FAB⁺) calc. for C₃₅H₃₅ ³⁵C1N₅O₁₀ (MH⁺) m/z 720.2073, found 720.2059; calc. for C₃₅H₃₅ ³⁷C1N₅O₎₀ (MH⁺) m/z 722.2043, found 722.2031; Anal. (C₃₅H₃₄C1N₅O₁₀) C, H, N.

Example 9B. Preparation of (l-methyl-2-nitro-lH-pyrrol-3-yl)methyl 1- (chloromethyl)-3-[(5,6,7-trimethoxy-lH-indol-l-yl)carbonyl]-2,3-dihydro-lH- benzo[e]indol-5-ylcarbamate (169).

(l-methyI-2-nitro-lH-pyrrol-3-yl)methanoI (168). A solution of NaOH (2.7 g, 68 mmol) in water (15 mL) was added to a solution of ester 166 (1.02 g, 4.47 mmol) in EtOH (30 mL), and the mixture was stiπed at 20 °C for 1 h. The EtOH was evaporated, and the aqueous phase washed with EtOAc (20 mL) and then acidified (HCI). The aqueous mixture was extracted with EtOAc (3 ' 50 mL), the combined organic extract was dried and the solvent evaporated to give crude 4-(hydroxymethyl)-l-methyl-5-nitropyrrole-2-carboxylic acid (0.84 g, 96%) as a red-brown solid. The acid was suspended in quinoline (6 mL) with Cu powder (0.44 g) and the mixture was heated at 170-180 °C for 50 min. The cooled mixture was diluted with HCI (2N), extracted with EtOAc (3 ' 50 mL), the combined extract was dried, and the solvent evaporated. The residue was purified by chromatography, eluting 40% EtOAc/light petroleum, to give 168 as a pink solid (0.45 g, 64%), mp (benzene) 79-80.5 °C; Η NMR δ 6.78 (d, J= 2.8 Hz, 1 H, H 5), 6.27 (d, J= 2.5 Hz, 1 H, H 4), 4.80 (d, J= 6.8 Hz, 2 H, CH₂O), 4.00 (s, 3 H, NCH₃), 2.75 (t, J= 6.8 Hz, 1 H, OH); ¹³C NMR δ 131.6 (C 3), 129.1 (C 4), 109.0 (C 5), 58.8 (CH₂O), 38.6 (NCH₃); Anal. (C₆H₈N₂O₃) C, H, N.

(l-Methyl-2-nitro-l^-pyrrol-3-yl)methyl l-(chloromethyl)-3-[(5,6,7-trimethoxy-lH- indol-l-yl)carbonyl]-2,3-dihydro-lH-benzo[e]indol-5-ylcarbamate (169). A solution of triphosgene (13.3 mg, 45 μmol) in DCM (2 mL) was added dropwise to a stirred solution of amine 1 [G. J. Atwell, W. R. Wilson, W. A. Denny. Bioorg. Med. Chem. Lett., 1997, 7, 1483] (53 mg, 114 μmol) and Et₃N (36 μL, 256 μmol) in DCM (10 mL) and stirred at 20 °C for 2 h. A solution of (l-methyl-2-nitro-lH-pyrrol-3-yl)methanol (168) (24 mg, 153 μmol) in DCM (2 mL) was added, followed by nBu₂Sn(OAc)₂ (2 drops) and the solution stirred at 20 °C for 24 h. The solvent was evaporated and the residue purified by chromatography, eluting with a gradient (10-20%) of EtOAc/DCM, to give 169 (21 mg, 28%) as a white solid, mp (EtOAc) 218-220 °C; Η NMR [(CD₃)₂SO] δ 11.46 (br s, 1 Η, indole-NH), 9.80 (br s, 1 H, OCONH), 8.55 (br s, 1 H, H 4), 8.09 (d, J= 8.5 Hz, 1 H, H 6), 7.98 (d, J= 8.3 Hz, 1 H, H 9), 7.58 (dd, J= 8.3, 7.3 Hz, 1 H, H 8), 7.48 (dd, J= 8.5, 7.3 Hz, 1 H, H 7), 7.33 (d, J- 2.6 Hz, 1 H, H 4"), 7.09 (d, J= 1.9 Hz, 1 H, H 3'), 6.98 (s, 1 H, H 4'), 6.37 (br s, 1 H, H 3"), 5.37 (s, 2 H, CH₂O), 4.80 (dd, J= 11.0, 9.3 Hz, 1 H, H 2), 4.52 (dd, J= 11.0, 1.9 Hz, 1 H, H 2), 4.31-4.37 (m, 1 H, H 1), 4.07 (dd, J= 11.1, 3.0 Hz, 1 H, CH₂C1), 3.96 (s, 3 H, NCH₃), 3.91-3.94 (m, 4 H, CH₂C1, OCH₃), 3.82 (s, 3 H, OCH₃), 3.80 (s, 3 H, OCH₃); ¹³C NMR [(CD₃)₂SO] δ 160.2 (CO), 154.4 (OCONH), 149.1 (C 5'), 141.5 (C 3a), 139.9 (C 6'), 139.0 (C 7'), 134.3 (C 5), 133.2 (C 2"), 130.7 (C 9a), 129.4 (C 2'), 127.1 (C 8), 125.4 (C 5a), 125.3 (C 7a'), 124.3 (C 7), 123.8 (C 9), 123.3 (C 6), 123.1 (C 3a'), 122.0 (C 9b), 113.0 (C 4), 108.1 (C 5"), 106.1 (C 3'), 98.0 (C 4'), 61.0 (OCH₃), 60.9 (OCH₃), 60.2 (CH₂O), 55.9 (OCH₃), 54.8 (C 2), 47.5 (CH₂C1), 41.1 (C 1), 37.9 (NCH₃); MS (FAB⁺) m/z 650 (MH⁺, 1.5%), 648 (MH⁺, 3.5); HRMS (FAB⁺) calc. for C₃₂H₃₁ ³⁵ClN₅O₈ (MH⁺) m/z 648.1861, found 648.1844; calc. for C₃₂H₃₁ ³⁷ClN₅O₈ (MH⁺) m/z 650.1832, found 650.1826; Anal. (C₃₂H₃₀C1N₅O₈) C, H, N.

Example 9C. Preparation of ethyl 5-({[({l-(chloromethyl)-3-[(5,6,7-trimethoxy-lH- indol-l-yl)carbonyl]-2,3-dihydro-lH-benzo[e]indol-5-yl}amino)carbonyl]oxy}methyl)- l-methyl-4-nitro-lH-pyrrole-2-carboxylate (173).

Ethyl 5-formyl-l-methyl-4-nitro-lH-pyrrole-2-carboxylate (171). Dimethyl sulfate (0.31 mL, 3.2 mmol) was added to a mixture of ethyl 5-formyl-4-nitro- lH-pyrrole-2- carboxylate (170) [P. Fornari, M. Farmer, C. Fournier, Bull. Soc. Chim. Fr. 1972, 283-291] (0.57 g, 2.7 mmol) and K₂CO₃ (0.56 g, 4.0 mmol) in DMSO (4 mL) and the brown suspension was stirred at 20 °C for 1 h. The mixture was diluted with water (50 mL), acidified with ΗC1 (2 N), and extracted with EtOAc (2 x 50 mL). The combined extract was dried, the solvent evaporated. The residue was chromatograped, eluting with

10%EtO Ac/light petroleum, to give 171 as a pale green solid (89%), mp (benzene/light petroleum) 70.5-71.5 °C; Η NMR δ 10.55 (s, 1 Η, CΗO), 7.49 (s, 1 Η, Η 3), 4.38 (q, J = 7.2 Ηz, 2 Η, CΗ₂), 4.33 (s, 3 H, NCH₃), 140 (t, J= 7.2 Hz, 3 H, CH₃); Anal. (C₉H₁₀N₂O₅) C, H, N.

Ethyl 5-(hydroxymethyl)-l-methyl-4-nitro-lH-pyrrole-2-carboxylate (172). NaBH₄ (0.33 g, 8.7 mmol) was added in portions to a solution of aldehyde 171 (3.96 g, 17.5 mmol) in EtOH (100 mL) and the mixture was stiπed at 20 °C for 20 min. Water (5 mL) was slowly added, the EtOH was evaporated, and the residue was diluted with brine and extracted with EtOAc (2 ' 50 mL). The combined extract was washed with brine (50 mL), dried, and the solvent evaporated. The residue was recystallized to give 172 as a cream solid (81%), mp (benzene) 1 19-120.5 °C; 'H NMR δ 7.48 (s, 1 H, H 3), 4.97 (d, J= 6.8 Hz, 2 H, CH₂O), 4.32 (q, J= 7.1 Hz, 2 H, CH₂), 4.06 (s, 3 H, NCH₃), 2.72 (t, J= 7.1 Hz, 1 H, OH), 1.37 (t, J= 7.1 Hz, 3 H, CH₃); Anal. (C₉H₁₂N₂O₅) C, H, N.

Ethyl 5-({[({l-(chloromethyl)-3-[(5,6,7-trimethoxy-lH-indol-l-yl)carbonyI]-2,3- dihydro-lH-benzo[e]indol-5-yl}amino)carbonyl]oxy}methyl)-l-methyl-4-nitro-lH- pyrrole-2-carboxylate (173). A solution of triphosgene (13.5 mg, 46 μmol) in DCM (2 mL) was added dropwise to a stiπed solution of amine 1 [G. J. Atwell, W. R. Wilson, W. A. Denny, Bioorg. Med. Chem. Lett., 1997, 7, 1483] (54 mg, 116 μmol) and Et₃N (36 μL, 260 μmol) in DCM (10 mL) and stiπed at 20 °C for 2 h. A solution of ethyl 5- (hydroxymethyl)-l-methyl-4-nitro-lH-pyrrole-2-carboxylate (172) (36 mg, 156 μmol) in DCM (2 mL) was added, followed by nBu₂Sn(OAc)₂ (2 drops) and the solution stiπed at 20 °C for 24 h. The solvent was evaporated and the residue purified by chromatography, eluting with 40% EtOAc/DCM, to give 173 (52 mg, 62%) as a white solid, mp (EtOAc/light petroleum) 227-229 °C; 'Η NMR [(CD₃)₂SO] δ 11.46 (s, 1 Η, indole-NΗ), 9.83 (s, 1 Η, OCONΗ), 8.56 (br s, 1 Η, Η 4"), 8.02 (d, J= 8.5 Ηz, 1 Η, Η 6"), 7.97 (d, J= 8.3 Ηz, 1 Η, Η 9"), 7.57 (dd, J= 8.3, 7.4 Ηz, 1 Η, Η 8"), 7.46 (dd, J= 8.5, 74 Ηz, 1 Η, Η 7"), 7.43 (s, 1 Η, Η 3), 7.10 (d, J= 2.0 Ηz, 1 Η, Η 3'"), 6.98 (s, 1 Η, Η 4"'), 5.63 (s, 2 Η, CΗ₂O), 4.80 (dd, J= 11.0, 9.4 Hz, 1 H, H 2"), 4.53 (dd, J= 11.0, 1.9 Hz, 1 H, H 2"), 4.33- 4.37 (m, 1 H, H 1"), 4.29 (q, J= 7.1 Hz, 2 H, H 1 '), 4.00-4.08 (m, 4 H, CH₂C1, NCH₃), 3.91-3.95 (m, 4 H, CH₂C1, OCH₃), 3.83 (m, 3 H, OCH₃), 3.80 (s, 3 H, OCH₃), 1.31 (t, J = 7.1 Hz, 3 H, H 2'); ¹³C NMR [(CD₃)₂SO] δ 160.1 (CO), 159.3 (CO₂), 154.0 (OCONH), 149.1 (C 5'"), 141.4 (C 3a"), 139.9 (C 6'"), 139.0 (C 7'"), 134.1 (C 5"), 133.6 (C 4), 133.4 (C 2), 130.7 (C 9a"), 129.4 (C 2'"), 127.1 (C 8"), 125.4 (C 5a"), 125.3 (C 7a'"), 124.3 (C 7"), 123.7 (C 9"), 123.3 (C 6"), 123.1 (C 3a'"), 122.4 (C 5), 122.1 (C 9b"), 113.0 (C 4"), 111.2 (C 3), 106.2 (C 3'"), 98.0 (C 4'"), 61.0 (OCH₃), 60.9 (OCH₃), 60.8 (CH₂O), 55.9 (OCH₃), 54.8 (C 2"), 54.6 (C 1'), 47.5 (CH₂C1), 41.1 (C 1"), 33.6 (NCH₃) 13.9 (C 2'); MS (FAB⁺) m/z 722 (MH⁺, 2.5%), 720 (MH⁺, 6); HRMS (FAB⁺) calc. for C₃₅H₃₅ ³⁵C1N₅O₁₀ (MH⁺) m/z 720.2073, found 720.2045; calc. for C₃₅H₃₅ ³⁷C1N₅O_IO (MH⁺) m/z 722.2043, found 722.2039; Anal. (C₃₅H₃₄C1N₅O₁₀) C, H, N.

Example 9D. Preparation of (l-methyI-3-nitro-li/-pyrrol-2-yl)methyl 1- (chloromethyl)-3-[(5,6,7-trimethoxy-lH-indol-l-yl)carbonyl]-2,3-dihydro-l^- benzo[e]indol-5-ylcarbamate (175).

2-(HydroxymethyI)-l-methyl-3-nitropyrrole (174). A solution of NaOH (1 M, 16.7 mL, 16.7 mmol) was added to a solution of ester 172 (0.76 g, 3.34 mmol) in EtOH (50 mL), and the mixture was stiπed at 20 °C for 1 h. The EtOH was evaporated, water (50 mL) added and the aqueous phase washed with diethyl ether (50 mL). The pH of the aqueous phase was adjusted to 2 with 1 M HCI. The aqueous mixture was extracted with EtOAc (3 ' 50 mL), the combined organic extract was dried and the solvent evaporated to give crude 4- (hydroxymethyl)-l-methyl-5-nitropyπole-2-carboxylic acid (0.65 g, 97%) as a red-brown solid. The acid was suspended in quinoline (10 mL) with Cu powder (0.50 g) and the mixture was heated at 180- 190 °C for 50 min under N₂. The cooled mixture was diluted with EtOAc (50 mL) and 1 M HCI (50 mL), extracted with EtOAc (3 ' 50 mL), the combined extract was dried, and the solvent evaporated. The residue was purified by chromatography, eluting 50% EtOAc/light petroleum, to give 174 as a pale yellow solid (0.29 g, 57%), mp 63-64 °C (benzene); 'H NMR δ 6.73 (d, J= 3.4 Hz, 1 H, H 5), 6.50 (d, J= 3.4 Hz, 1 H, H 4), 4.89 (d, J= 7.2 Hz, 2 H, CH₂O), 3.73 (s, 3 H, NCH₃), 2.83 (t, J= 7.2 Hz, 1 H, OH); ¹³C NMR δ 134.9 (C 3), 133.5 (C 2), 122.0 (C 4), 105.7 (C 5), 53.8 (CH₂O), 34.8 (NCH₃); Anal. (C₆H₈N₂O₃) C, H, N.

(l-Methyl-3-nitro-lH-pyrrol-2-yl)methyl l-(chloromethyl)-3-[(5,6,7-trimethoxy-lH- indol-l-yl)carbonyl]-2,3-dihydro-l/f-benzo[e]indol-5-ylcarbamate (175). A solution of triphosgene (15 mg, 50 μmol) in DCM (2 mL) was added dropwise to a stirred solution of amine 1 [G. j. Atwell, W. R. Wilson, W. A. Denny, Bioorg. Med. Chem. Lett., 1997, 7, 1483] (59 mg, 127 μmol) and Et₃N (40 μL, 284 μmol) in DCM (10 mL) and stirred at 20 °C for 2 h. A solution of alcohol 174 (27 mg, 171 μmol) in DCM (2 mL) was added, followed by nBu₂Sn(OAc)₂ (2 drops) and the solution stirred at 20 °C for 24 h. The solvent was evaporated and the residue purified by chromatography, eluting with a gradient (20- 30%) of EtOAc/DCM, to give 175 (11 mg, 13%) as a white solid, mp (EtOAc) 218-220 °C; Η NMR δ 9.42 (s, 1 H, indole-NH), 8.94 (s, 1 H, OCONH), 7.87 (d, J= 8.4 Hz, 1 H, H 6), 7.79 (d, J= 8.2 Hz, 1 H, H 9), 7.57 (ddd, J= 8.2, 7.4, 0.9 Hz, 1 H, H 8), 7.47 (ddd, J- 8.4, 7.4, 0.9 Hz, 1 H, H 7), 7.08 (br s, 1 H, H 4), 7.01 (d, J= 2.2 Hz, 1 H, H 3'), 6.89 (s, 1 H, H 4'), 6.80 (d, J= 3.3 Hz, 1 H, H 5"), 6.57 (d, J= 3.3 Hz, 1 H, H 4"), 5.65 (s, 2 H, CH₂O), 4.81 (dd, J= 10.7, 91.7 Hz, 1 H, H 2), 4.67 (dd, J= 10.7, 8.6 Hz, 1 H, H 2), 4.15-4.20 (m, 1 H, H 1), 4.10 (s, 3 H, OCH₃), 3.95-3.99 (m, 4 H, OCH₃, CH-C1), 3.92 (s, 3 H, OCH₃), 3.80 (br s, 3 H, NCH₃), 3.48 (dd, 7 = 11.0, 10.7 Hz, 1 H, CH₂C1); ¹³C NMR δ 160.4 (CO), 153.9 (OCONH), 150.2 (C 5'), 141.6 (C 3a), 140.6 (C 6'), 138.9 (C 7'), 133.7 (C 5), 130.9 (C 3"), 129.7 (C 9a), 129.6 (C 2'), 128.8 (C 2"), 127.5 (C 8), 125.6 (C 7a'), 125.1 (C 7, C 5a), 123.6 (C 3a'), 123.1 (C 9), 122.6 (C 6), 122.2 (C 4"), 121.6 (C 9b), 113.0 (C 4), 106.5 (C 3'), 106.1 (C 5"), 97.7 (C 4'), 61.5 (OCH₃), 61.1 (OCH₃), 56.3 (OCH₃), 55.3 (CH₂O), 54.9 (C 2), 45.8 (CH₂C1), 43.4 (C 1), 35.3 (NCH₃); MS (FAB⁺) m/z 650 (MH⁺, 0.6%), 648 (MH⁺, 1.5); HRMS (FAB⁺) calc. for C₃₂H₃₁ ³⁵ClN₅O₈ (MH⁺) m/z 648.1861, found 648.1850; calc. for C₃₂H₃₁ ³⁷ClN₅O₈ (MH⁺) m/z 650.1832, found 650.1841; Anal. (C₃₂H₃₀C1N₅O₈) C, H, N.

Example 9E. Preparation of (l-methyl-5-nitro-l/ -pyrrol-2-yI)methyl 1-

(chloromethyI)-3-[(5,6,7-trimethoxy-lH-indol-l-yl)carbonyI]-2,3-dihydro-lH- benzo[e]indol-5-ylcarbamate (178).

(l-Methyl-5-nitro-lH-pyrrol-2-yl)methanol (177). NaBH₄ (0.19 g, 5.03 mmol) was added to a stirred solution of l-methyl-5-nitro-lH-pyrrole-2-carbaldehyde (176) [ P. Fournari, Bull. Soc. Chim. Fr. 1963, 488-491] (0.78 g, 5.07 mmol) in MeOΗ (40 mL) at room temperature under N₂. After addition was complete, the reaction mixture was stirred for a further 20 min, then water (40 mL) was added and the mixture was saturated with solid K₂CO₃. The mixture was extracted with EtOAc (3 ' 50 mL), the combined organic fraction dried, and the solvent evaporated to give 177 (0.77 g, 97%)as a white solid, mp (EtOAc/light petroleum) 76-77 °C; Η NMR δ 7.16 (d, J= 4.3 Ηz, 1 Η, Η 4), 6.17 (d, J = 4.3 Ηz, 1 Η, Η 3), 4.68 (s, 2 Η, CΗ₂), 4.02 (s, 3 H, CH₃); Anal. (C₆H₈N₂O₃) C, H, N.

(l-Methyl-5-nitro-lH-pyrrol-2-yl)methyl l-(chloromethyl)-3-[(5,6,7-trimethoxy-lH- indol-l-yl)carbonyl]-2,3-dihydro-lH-benzo[e]indol-5-ylcarbamate (178). A solution of triphosgene (16 mg, 52 μmol) in DCM (2 mL) was added dropwise to a stirred solution of amine 1 [G. J. Atwell, W. R. Wilson, W. A. Denny, Bioorg. Med. Chem. Lett., 1997, 7, 1483] (62 mg, 133 μmol) and Et₃N (42 μL, 299 μmol) in DCM (10 mL) and stirred at 20 °C for 2 h. A solution of alcohol 177 (28 mg, 179 μmol) in DCM (2 mL) was added, followed by nBu₂Sn(OAc)₂ (2 drops) and the solution stirred at 20 °C for 24 h. The solvent was evaporated and the residue purified by chromatography, eluting with 20% EtOAc/DCM, to give 178 (54 mg, 63%) as a white solid, mp (EtOAc) 212-214 °C; Η NMR [(CD₃)₂SO] δ 11.45 (br s, 1 H, indole-NH), 9.82 (br s, 1 H, OCONH), 8.55 (br s, 1 H, H 4), 8.04 (d, J= 8.5 Hz, 1 H, H 6), 7.89 (d, J= 8.3 Hz, 1 H, H 9), 7.57 (dd, J= 8.3, 7.2 Hz, 1 H, H 8), 7.45 (dd, J= 8.5, 7.2 Hz, 1 H, H 7), 7.24 (d, J= 4.4 Hz, 1 H, H 4"), 7.09 (d, J= 2.0 Hz, 1 H, H 3'), 6.98 (s, 1 H, H 4'), 6.45 (d, J= 4.4 Hz, 1 H, H 3"), 5.30 (s, 2 H, CH₂O), 4.80 (dd, J = 11.0, 9.4 Hz, 1 H, H 2), 4.53 (dd, J = 11.0, 1.8 Hz, 1 H, H 2), 4.32- 4.37 (m, 1 H, H 1), 4.07 (dd, J= 11.1, 3.1 Hz, 1 H, CH₂C1), 3.91-3.96 (m, 7 H, CH₂C1, NCH₃, OCH₃), 3.83 (s, 3 H, OCH₃), 3.81 (s, 3 H, OCH₃); ¹³C NMR [(CD₃)₂SO] δ 160.2 (CO), 154.0 (OCONH), 149.1 (C 5'), 142.1 (C 5"), 141.4 (C 3a), 139.9 (C 6'), 138.2 (C 7'), 136.1 (C 2"), 134.2 (C 5), 130.7 (C 9a), 129.4 (C 2'), 127.1 (C 8), 125.3 (C 5a), 125.2 (C 7a'), 124.3 (C 7), 123.7 (C 9), 123.3 (C 6), 123.1 (C 3a'), 122.1 (C 9b), 113.1 (C 3"), 113.0 (C 4), 110.6 (C 4"), 106.2 (C 3'), 98.0 (C 4'), 61.0 (OCH₃), 60.9 (OCH₃), 57.6

(CH₂O), 55.9 (OCH₃), 54.8 (C 2), 47.5 (CH₂C1), 41.1 (C 1), 33.9 (NCH₃); MS (FAB⁺) m/z 650 (MH⁺, 1%), 648 (MH⁺, 2); HRMS (FAB⁺) calc. for C₃₂H₃₁ ³⁵ClN₅O₈ (MH⁺) m/z 648.1861, found 648.1852; calc. for C₃₂H₃₁ ³⁷ClN₅O₈ (MH⁺) m/z 650.1832, found 650.1836; Anal. (C₃₂H₃₀C1N₅O₈) C, H, N.

Elemental analysis data

Example 10

Biological activity Selected compounds were evaluated for cytotoxicity (measured as IC₅₀ values in μM following and 18 h drug exposure) in pairs of mammalian cell lines, and the results are given in Table 2. The human ovarian carcinoma line (SKOV3) is wild-type, while the SC3.2 line is the NR+ transfectant. The human colon carcinoma line NR- line (WIDR) is wild-type, while the WC14.10 line is the NR+ transfectant. The murine mammary carcinoma (EMT6-V) is wild-type, while the EN2A is the NR+ transfectant. Ratios (NR- /NR+) provide a major measure of efficacy of action.

Table 3. Biological activity for selected compounds.

Example No SKOV3 SKOV/ WiDr WiDr/ EMT6-V EMT6/ SC3.2 WC14.10 EN2A

NR- IC₅₀ ratios NR- Ratio NR- Ratio

IC,„(μmol) IC,₀(μmol) IC,_nC mol)

2C 35 0.059 16.6 0.14 47 - -

2E 38 2.45 5.9 2.78 3.1 - -

2F 42 >10 - >10 >16 3.33 >54

2G 46 1.81 3.9 1.21 3.3 0.76 49

2H 51 5.3 8.1 2.8 3.6 0.62 2.44 B 60 0.157 5.6 0.15 6.6 - . A 70 0.224 84 0.30 147 0.106 104 B 73 0.105 67 0.109 45 0.033 78 E 84 0.145 58 0.19 91 0.47 91 G 91 9.4 >36 6.6 22 1.6 15.6 1 99 0.114 40 0.13 25 0.44 13.4 K 105 0.088 6.4 0.097 9 0.024 6.1 B 123 2.3 28 1.7 6.7 - - C 124 0.075 21 0.075 40 - - D 125 3.74 14.5 3.59 10.3 0.46 6.4 E 129 >1.5 >12 >1.5 >5.6 0.24 4.95 1 138 0.15 50 0.23 99 0.078 71 J 142 >3 >9.0 2.72 1.64 0.23 >1.22 K 148 0.23 30 0.38 <38 0.067 <7 L 150 0.061 5.6 0.024 3.4 0.063 6.5 B 160 0.01 7.0 0.018 13.5 0.004 16.5

8 163 0.032 30 0.011 13.5 0.039 87 A 167 0.097 9.6 0.094 13.2 0.028 11.6

Claims

1. A compound of formula (I) or (II): wherein: X represents H, C,.₆ alkyl or C,_₆ alkoxy, said alkyl or alkoxy being optionally

substituted with one or more of the following groups: hydroxy (OH), ether (OR , amino (NH₂), mono-substituted amino (NR^H), di-substituted amino (NR^ ^²), cyclic C,.₅ alkylamino, imidazolyl, C,_₆ alkylpiperazinyl, morpholino, thiol (SH), thioether (SR , tetrazole, carboxy (COOH), carboxylate (COORJ, sulphoxy (S(=O)₂OH), sulphonate (S(=O)₂OR_x), sulphonyl (S(=O)₂R_»), sulphixy (S(=O)OH), sulphinate (S(=O)OR_x), sulphinyl (S(=O)R_x), phosphonooxy (OP(=O)(OH)₂) and phosphate (OP(=O)(OR ₂), where W , R_* ¹ and R^ are selected from a C,.₆ alkyl group, a C₃.₂₀ heterocyclyl group or a C_5.20 aryl group; a is 0,1,2,3 or 4; Y represents H or C,.₆ alkyl; 1, 2 or 3 of the members Z of the 5-membered aromatic ring are independently selected from -O-,-S-,-N= or -NR-, where R is H or C,_.6 alkyl optionally substituted with one or more of the following groups: hydroxy (OH), ether (OR_R), amino (NH₂), mono-substituted amino (NR_RH), di-substituted amino (NR_R'R_R ²), cyclic C,_.5 alkylamino, imidazolyl, alkylpiperazinyl, moφholino, thiol (SH), thioether (SR_R), tetrazole, carboxy (COOH), carboxylate (COOR_R), sulphoxy (S(=O)₂OH), sulphonate (S(=O)₂OR_R), sulphonyl (S(=O)₂R_R), sulphixy (S(=O)OH), sulphinate (S(=O)OR_R), sulphinyl (S(=O)R_R), phosphonooxy (OP(=O)(OH)₂) and phosphate (OP(=O)(OR_R)₂), where R_R, R_R' and R_R ² are selected from a C,.₆ alkyl group, a C_3.20 heterocyclyl group or a C₅.₂₀ aryl group, the other ring atoms being C; n is 0 or 1 ; and E represents a moiety such that EH is an amine; provided that in formula (I) if a = 0 then Y ≠ H.

2. A compound according to claim 1 wherein EH is a cytotoxic amine.

3. A compound according to claim 2, wherein E is selected from formulae (III-XIII); wherein, R, represents H or C,_₆ alkyl, being optionally substituted with one or more of the following groups: one or more of the following groups: hydroxy (OH), ether (OR_E), amino (NH₂), mono-substituted amino (NR_EH), di-substituted amino (NR_E'R_E ²), cyclic C,_.5 alkylamino, imidazolyl, C,.₆ alkylpiperazinyl, moφholino, thiol (SH), thioether (SR_E), tetrazole, carboxy (COOH), carboxylate (COOR_E), sulphoxy (S(=O)₂OH), sulphonate (S(=O)₂OR_E), sulphonyl (S(=O)₂R_E), sulphixy (S(O)OH), sulphinate (S(=O)OR_E), sulphinyl (S(=O)R_E), phosphonooxy (OP(=O)(OH)₂) and phosphate (OP(-O)(OR_E)₂), where R_E, R_E" and R_E ² are selected from a C,.₆ alkyl group, a C₃.₂₀ heterocyclyl group or a C₅.₂₀ aryl group; R₂ represents H, C_M alkyl, C_w alkoxy, OH, halogen, NO₂, NH₂, NHMe, NMe₂, SO₂Me, CF₃, CN, CONH₂ or CONHMe; each R₃ is independently selected from Cl, Br, I and OMS; and R₄ is selected from -C(=O)Me and -C(=O)CH₂OH; Q represents substituted indole, substituted benzoftiran or substituted cinnamoyl; in (IX) and (X), each n is independently from 2-4, and each m is independently from 2-4, and p = 0 or 1.

4. A compound according to any one of the preceding claims, wherein R^, R_x ¹, R^, R_R, R_R' and R_R ² are independently C,.₆ alkyl groups.

5. A compound according to any one of the preceding claims, wherein the compound is of formula (I) and a is 1.

6. A compound according to claim 5, wherein X represents optionally substituted C,_.6 alkoxy.

7. A compound according to claim 6, wherein the optionally substituted C,_.6 alkoxy is in the 2 position.

8. A compound according to claims 7 or 8, wherein the C,.₆ alkoxy group is selected from methyl, ethyl and n-propyl.

9. A compound according to any one of claims 6 to 8, wherein the C^ alkoxy group substituents are selected from hydroxy, methoxy, phosphonoxy, NMe₂, Nmoφh, OCO₂-tBu, and OCO₂H.

10. A compound according to claim 9, wherein the C,.₆ alkoxy group is ethoxy or n- propyl group with a single substituent.

11. A compound according to claim 10, wherein the ethyl or n-propyl substituent is hydroxy.

12. A compound according to any one of claims 6 to 8, wherein the C,^ alkoxy group is unsubstituted methyl.

13. A compound according to any one of claims 5 to 12, wherein Y is either H or Me.

14. A compound according to anyone of claims 5 to 13, wherein E is of formula V.

15. A compound according to any one of claims 5 to 13, wherein E is of formula XIII.

16. A compound according to claim 15, wherein n = 1.

17. A compound according to any one of claims 1 to 4, wherein the compound is of formula (II) with two Z, one Z being -N= and the other Z being -NR-.

18. A compound according to claim 17, wherein R is either Me or Et.

19. A compound according to claim 18, wherein R is Et substituted with hydroxy.

20. A compound according to any one of claims 17 to 19, wherein a is 0.

21. A compound according to any one of claims 17 to 20, wherein the -N= and -NR- are not adjacent in the heterocyclic ring.

22. A compound according to any one of claims 17 to 21, wherein E is of formula V.

23. A compound according to any one of claims 17 to 21, wherein E is of formula XHI.

24. A compound according to claim 23, wherein n = 1.

25. A compound according to any one of claims 1 to 4, wherein the compound is of formula (II), a is 0, and Z is selected from O or S.

26. A compound according to any one of claims 1 to 4, wherein the compound is of formula (II), Z is NR, and a is either 0 or 1.

27. A compound according to claim 26, wherein Z is NMe.

28. A compound according to either claim 26 or 27, wherein a is 1 and X is CO₂Et.

29. A compound according to any one of the preceding claims for pharmaceutical use.

30. A pharmaceutical composition comprising a compound according to any one of claims 1 to 28 and a pharmaceutically acceptable carrier or diluent.

31. A two component system for the treatment of neoplastic disease which comprises: (i) a vector encoding and capable of expressing a nitroreductase enzyme in a tumour cell; and

(ii) a compound as defined in any one of claims 1 to 28.

32. A two component system for the treatment of neoplastic disease which comprises: (i) a tumour directed antibody linked to a nitroreductase enzyme; and

(ii) a compound as defined in any one of claims 1 to 28.

33. A compound according to any one of claims 1 to 28, a composition according to claim 26, or a system according to claims 31 or 32 for use in a method of medical treatment.

34. A method of treating neoplastic disease which comprises administering to a patient in need of treatment an effective amount of a compound according to any one of claims 1 to 28, a composition according to claim 30, or a system according to claims 31 or 32.

35. The use of a compound according to any one of claims 1 to 28 for the manufacture of a composition for use in the treatment of a hyper-proliferative disease.

36. A method of providing an amine with a protecting group comprising:

(i) providing a plurality of different compounds selected from compounds of formulae (I) and

(II) wherein:

X represents H, C,.₆ alkyl or C,.₆ alkoxy, said alkyl or alkoxy being optionally substituted with one or more of the following groups: hydroxy (OH), ether (ORJ, amino

(NH₂), mono-substituted amino (NR_χH), di-substituted amino (NR^R^), cyclic C 1-5 alkylamino, imidazolyl, C,_₆ alkylpiperazinyl, moφholino, thiol (SH), thioether (SRJ, tetrazole, carboxy (COOH), carboxylate (COORJ, sulphoxy (S(=O)₂OH), sulphonate (S(=O)₂OR_x), sulphonyl (S(=O)₂R_x), sulphixy (S(=O)OH), sulphinate (S(=O)OR , sulphinyl (S(=O)R_x), phosphonooxy (OP(=O)(OH)₂) and phosphate (OP(=O)(OR ₂), where R,, R,¹ and R_χ ² are selected from a C,_₆ alkyl group, a C₃.₂₀ heterocyclyl group or a C₅.₂₀ aryl group; a is 0,1,2,3 or 4; Y represents H or C,^ alkyl; 1, 2 or 3 of the members Z of the 5-membered aromatic ring are independently selected from -O-,-S-,-N= or -NR-, where R is H or C,^ alkyl optionally substituted with one or more of the following groups: hydroxy (OH), ether (OR_R), amino (NH₂), mono-substituted amino (NR_RH), di-substituted amino (NR_R'R_R ²), cyclic C,_₅ alkylamino, imidazolyl, alkylpiperazinyl, moφholino, thiol (SH), thioether (SR_R), tetrazole, carboxy (COOH), carboxylate (COOR_R), sulphoxy (S(=O)₂OH), sulphonate (S(=O)₂OR_R), sulphonyl (S(=O)₂R_R), sulphixy (S(=O)OH), sulphinate (S(=O)OR_R), sulphinyl (S(=O)R_R), phosphonooxy (OP(=O)(OH)₂) and phosphate (OP(=O)(OR_R)₂), where R_R, R_R' and R_R ² are selected from a C,^ alkyl group, a C₃.₂₀ heterocyclyl group or a C₅.₂₀ aryl group, the other ring atoms being C; n is 0 or 1 ; and E represents a moiety such that EH is an amine; (ii) measuring the rates of fragmentation of the compounds to release EH when the nitro group is reduced and selecting a compound having a desired rate of decomposition; and (iii) providing the amine to be protected with a protecting group coπesponding to that in the selected compound.