WO2004111052A1 - Pyrrolopyrimidine derivatives as modulators of multi-drug resistance (mdr) - Google Patents

Abstract

A compound which is a pyrrolopyrimidine of formula (I) wherein R1 is selected from H, Cl-C6 alkyl which is unsubstituted or substituted, (CH2)nAr1, (CH2)pNR4R5, halogen and (CH2)pX; R2 is CH2)pArl; R3 is selected from H, Cl -C6 alkyl which is unsubstituted or substituted, (CH2)pZ and (CH2)pArl; P is an unsaturated 5, 6, or 7 membered carbocyclic or heterocyclic ring which is unsubstituted or substituted; R4 and R5 which are the same or different are selected from H, Cl -C6 alkyl which is unsubstituted or substituted, (CH2)nC3-C10 cycloalkyl, (CH2)nAr1 , and (CH2)nOR6, or R4 and R5 together with the nitrogen atom to which they are attached, form a saturated five or six membered nitrogen containing heterocyclic ring which may contain one extra heteroatom selected from 0, N and S and which is unsubstituted or substituted; R6 is selected from H, Cl -C6 alkyl which is unsubstituted or substituted, C3-C10 cycloalkyl, (CH2)nOC1-C6alkyl which is unsubstituted or substituted, (CH2)nO(CH2)nAr1 , (CH2)nCO2C1-C6,alkyl which is unsubstituted or substituted and (CH2)nAr1; X is selected from CN, azide, (CH2)nNHSO2R6 and (CH2)nNHCOR6; Z is selected from CN, CO2R6 and CONR4R5; Ar1 is the same or different when more than one is present within a given substituent group and is an unsaturated C6-C10 membered carbocylic group or an unsaturated 5-11 membered heterocycle, either of which is unsubstituted or substituted; p is an integer of 1 to 6; n is the same or different when more than one is present within a given substituent group and is 0 or an integer of 1 to 6; with the proviso that the pyrrolepyrimidine compound of formula (I) is other than 1-(4-benzyl-piperazin-1-yl)-9H-2,4,9-triaza-fluorene; and the pharmaceutically acceptable salts thereof, have activity as inhibitors of MRP (multidrug resistant protein) and may thus be used to modulate multidrug resistance, for instance in potentiating the cytotoxicity of a chemotherapeutic agent.

Description

PYRROLOPYRAMIDINE DERIVATIVES AS MODULATORS OF MULTI-DRUG RESISTANCE (MDR)

PHARMACEUTICAL COMPOUNDS

The present invention relates to compounds useful as modulators of multi-drag resistance (MDR), in particular resistance caused by over-production of the multidrug resistance protein (MRP), to their preparation and to pharmaceutical and veterinary compositions containing them.

Resistance to a range of drugs is frequently encountered during chemotherapy of many types of cancer. Such resistance may develop during drag treatment or may be an inherent feature of a particular tumour type. This phenomenon termed multidrug resistance has been studied in the laboratory where drag-resistant cell lines, derived by exposure to a single chemotherapeutic agent, become cross-resistant to many structurally and functionally unrelated compounds to which they have not been previously exposed. The drags encompassed by multidrug resistance include the anthracyclines, vinca alkaloids and epipodophyllotoxins.

Multidrug resistance is conferred by two different integral membrane proteins, the 17OkDa P-glycoprotein (Pgp) and the^" 19OkDa multidrug resistance protein (MRP). These proteins belong to the ATP-binding cassette (ABC) superfarnily of transport proteins, but their primary structures are quite dissimilar, sharing only 15% amino acid identity. Nevertheless, MRP and Pgp confer resistance to a similar profile of drugs. Both proteins efflux doxorubicin, daunorabicin, vincristine, etoposide and paclitaxel. There are however significant quantitative differences. For example, whereas Pgp produces relatively high levels of resistance to paclitaxel, the reverse is true for MRP (Loe DW, Deeley RG, Cole SPC. (1996) Biology of the multidrug resistance-associated protein. Eur J Cancer 32A 945-957). In addition to these neutral or cationic drags, MRP also transports a wide range of organic anions including glutathione conjugates, glucuronate conjugates, conjugated alkylating agents and some heavy metals (Cole SPC, Sparks KE, Fraser K. (1994) Pharmacological characterisation of multidrug resistant MRP- transfected human tumour cells. Cancer Res 54: 5902-5910).

MRP is widely distributed in normal tissues including peripheral blood, endocrine glands (adrenal and thyroid), striated muscle, lymphoreticular tissues (spleen and tonsil), tissues from the digestive tract (salivary gland, oesophagus, liver gall bladder, pancreas and colon), respiratory tract (lung) and urogenital tract (kidney, bladder, testis, and ovary).

ABC transporters such as MRP play an essential role in defending against toxic compounds. MRPl gene knockout mice (-/-) are hypersensitive to etoposide (Wijnholds J, Evers R, van Leusden MR, MoI CAAM, Zaman GJR, Mayer U, Beijnen JH, van der VaIk M, Krimpenfort P, Borst P (1997) Increased sensitivity to anticancer drugs and decreased inflammatory response in mice lacking MRP. Nat. Med. 11: 1275-1279) and this is especially seen in bone marrow, testis, kidney, the oropharyngeal mucosa - cells with a substantial MRP content (Wijnholds J, Scheffer M, van der VaIk M, Beijnen JH, Scheper RJ, Borst P (1998) MRP protects the oropharyngeal mucosal layer and the testicular tubules against drug induced damage. J. Exp. Med. 188: 797-808).

Some insight into the normal physiological role of MRP has also been obtained by the demonstration that membrane vesicles from MRP-overexpressing drug-selected and transfected cells support ATP-dependent transport of the cysteinyl leukotriene, (LTC₄) (Loe DW, Almquist KC, Deeley RG, Cole SPC. (1996) MRP-mediated transport OfLTC₄ and chemotherapeutic agents in membrane vesicles. J Biol Chem 271 9675-9682). The cysteinyl leukotrienes (LTC₄, LTD4 and LTE4) are potent mediators of inflammation that increase vascular permeability and smooth muscle contraction. LTC₄ is derived from arachidonic acid in a series of reactions that result in conjugation of glutathione and LTA₄ by LTC₄ synthase. It is then exported from the cell by MRP. LTC₄ is actively transported across the plasma membrane by MRP, and extracellularly LTD4 and LTE4 are formed by the action of γ- glutamyl transpeptidase and dipeptidase, respectively (Leier J, Jedlitschky G, Buchholz U, Cole SP, Deeley RG, Keppler D (1994). The MRP gene encodes an ATP-dependent export pump for Leukotriene C₄ and structurally related conjugates. J. Biol. Chem. 269: 27807-27810). LTC₄ synthase and MRP are both expressed in eosinophils and mast cells; these cell types play a pivotal role in asthma by IgE-mediated synthesis and release of cysteinyl leukotrienes.

Inhibition of MRP-mediated transport is being targeted as a mechanism for reversing resistance to cytotoxic drugs in different cancers (a multidrug resistance modulator). Inhibition OfLTC₄ transport by MRP in asthma may prevent associated inflammation and bronchoconstriction (LTC₄ efflux inhibitor).

The present invention provides a compound which is a pyrrolopyrimidine of formula (I)

wherein

R¹ is selected from H, C₁-C₆ alkyl which is unsubstituted or substituted, (CH₂)_HAr¹,

(CH₂)_PNR⁴R⁵, halogen and (CH₂)_PX;

R² is (CH₂)_PAr¹; R³ is selected from H, Cj-C₆ alkyl which is unsubstituted or substituted, (CH₂)pZ and

(CH₂)pAr';

P is an unsaturated 5, 6, or 7 membered carbocyclic or heterocyclic ring which is unsubstituted or substituted;

R⁴ and. R⁵, which are the same or different, are selected from H, Ci-C₆ alkyl which is unsubstituted or substituted, (CH₂)_nC₃-Ci₀ cycloalkyl, (C^_nAr¹ and (CH₂)_nOR⁶, or R⁴ and R⁵, together with the nitrogen atom to which they are attached, form a saturated five or six membered nitrogen containing heterocyclic ring which may contain one extra heteroatom selected from O, N and S and which is unsubstituted or substituted;

R⁶ is selected from H, C₁-C₆ alkyl which is unsubstituted or substituted, C₃-C₁₀ cycloalkyl, (CH₂)_nO-C_!-C₆ alkyl which is unsubstituted or substituted,

(CH₂)_nO(CH₂)_nAr¹, (CH₂)_nCO₂-Ci-C₆ alkyl which is unsubstituted or substituted, and

(CHa)_nAr¹;

X is selected from CN, azide, (CH₂)_nNHSO₂R⁶ and (CH₂)_nNHCOR⁶;

Z is selected from CN, CO₂R⁶ and CONR⁴R⁵ wherein R⁴, R⁵ and R⁶ are as defined above; Ar¹ is the same or different when more than one is present within a given substituent group and is an unsaturated C₆-C₁₀ membered carbocylic group or an unsaturated 5-11 membered heterocyclic group, either of which is unsubstituted or substituted; p is an integer of 1 to 6; and n is the same or different when more than one is present within a given substituent group and is 0 or an integer of 1 to 6; with the proviso that the pyrrolopyrimidine of formula (I) is other than l-(4-benzyl- piperazin-l-yl)-9H-2,4,9-triaza-fluorene; or a pharmaceutically acceptable salt thereof. The parameter n is, 0,1,2,3,4,5 or 6. Typically it is 0,1 ,2 or 3. Preferably it is 0,1 or 2.

. The parameter p is 1,2,3,4,5 or 6. Typically, it is 1,2 or 3. Preferably it is 1 or 2. A C₁-C₆ alkyl group is linear or branched. A Ci-C₆.alkyl group is typically a Ci- C₄ alkyl group, for example a methyl, ethyl, propyl, i-propyl, n-butyl, sec-butyl or tert- butyl group. A C₁-C₆ alkyl group is unsubstituted or substituted, typically by one or more groups selected from hydroxy C₁-C₆ alkyl wherein the alkyl moiety is unsubstituted or substituted, halo- Ci-C₆ alkyl wherein the alkyl moiety is unsubstituted or substituted, C₁- C₆ alkoxy, Ar², R¹², OR¹², SR¹², nitro, CN, halogen, -CO₂R¹², -C(O)NR¹⁰R¹¹, -NR¹²C(O)R¹², NR¹⁰R¹¹, -(CH₂)_nO(CH₂)_nAr², -0(CH₂)_HC(O)NR¹⁰R¹ \ -S(O)₂R¹², -N(C(O)(R¹²)₂, -S(O)₂NR¹⁰R¹¹, NR¹²S(O)₂R¹², R⁹, -(CH₂)_nNR¹⁰Rⁿ, -(CH₂)C(O)NR¹⁰R¹¹, -(CH₂)C(O)NR¹⁰R¹¹, -(CH₂)_nOR⁹, -(CH₂)_nC(O)(CH₂)_nR⁹, -(CH₂)_nC(O)NC(O)Ar² and- (CH₂)_nO(CH₂)_nAr², wherein R⁹, R¹², R¹⁰, R¹¹, and Ar² are as defined below. Preferred substituents include hydroxy, thio, hydroxyCi-C₆ alkyl, thioCi-C₆alkyl, halogen, halo-Ci-C₆alkyl, Ci-C₆alkoxy, alkylthio, nitro, CN, amino, Ci- C₆alkylamino, di-Ci-C₆-alkylamino, CONH₂, -CO₂H and esters thereof, preferably Ci-C₆ alkyl esters thereof.

Examples of hydroxy-Ci-C₆-alkyl include, for instance, hydroxymethyl, 1- hydroxyethyl and 2-hydoxyethyl. An example of halo-Ci-C₆ alkyl is trifluoromethyl. Preferred examples for P include benzene, pyridine (b- or c- fused) and pyridine-N-oxide (b- or c- fused).

A halogen is F, Cl, Br or I. Preferably it is F or Cl. Typically it is F. A C₃-C₁₀ cycloalkyl group may be cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, or cycloheptyl and is unsubstituted or substituted, for instance by one or more of the options specified above as substituents for C₁-C₆ alkyl. Typically it is C₃-C₆ cycloalkyl. A saturated 5- or 6-membered N-coήtaining heterocyclic ring may be, for example, piperidine, piperazine, morpholine or pyrrolidine. Suitable substituents for such a ring as found in the definition of R⁴ and R⁵ include C₁-C₆ alkyl which is unsubstituted or substituted as defined above, (CH₂)_nC(O)NR⁷R⁸, (CH₂)_nOR⁹, and (CH₂)_nCO₂R⁹, wherein R⁷, R⁸ and R⁹ are as defined below. Suitable substituents for a five- or six-membered nitrogen containing heterocyclic ring as found in the definition of R⁷ and R⁸ include C₁-C₆ alkyl which is unsubstituted or substituted, (CH₂)_nC(O)NR¹⁰R^u, (CH₂)_nOR¹² and (CH₂)_nCO₂R¹² wherein R¹⁰, R¹¹ and R¹² are as defined below. Suitable substituents for a five- or six-membered nitrogen containing heterocyclic ring as found in the definition of R¹⁰ and R¹¹ as defined below include Ci-C₆ alkyl which is unsubstituted or substituted as defined above, (CH₂)_nOR¹² and (CH₂)_nCO₂R¹² wherein R¹² is as defined below.

An unsaturated C₆-C io carboc.yclic group is a 6-, 7-, 8-, 9-, or 10-membered carbocyclic ring containing at least one unsaturated bond. It is a monocyclic or fused bicyclic ring system. The group is aromatic or non-aromatic. Examples include phenyl, naphthyl, indanyl, indenyl and tetrahydronapthyl groups. Typically, said group is phenyl. When an unsaturated C₆-Ci₀ carbocyclic group is substituted it is typically substituted by one or more groups selected from Ci-C₆ alkyl, (CH₂)_nOR⁹, halogen, nitro, CN, CO₂R⁹, C(O)NR⁷R⁸, NR⁹C(O)R⁹, NR⁷R⁸ , SR⁹, (CH₂)_nAr², O(CH₂)_nC(O)NR⁷R⁸, S(O)₂NR⁷R⁸, (CH₂)_nC(S)NR⁷R⁸ and NR⁹S(O)₂R⁹, or two adjacent atoms may be substituted by a methylenedioxy or an ethylenediόxy group, wherein

R⁷ and R⁸ which are the same or different are selected from H, Ci-C₆ alkyl which is unsubstituted or substituted, (CH₂)_nC₃-C₁₀ cycloalkyl, (CH^_nAr² and (CH₂)_nOR⁹, or R⁷ and R⁸ together with the nitrogen atom to which they are attached, form a saturated five or six membered nitrogen containing heterocyclic ring, which may contain one extra heteroatom selected from O, N and S and which is unsubstituted or substituted; R⁹ is the same or different when more than one is present within a given substituent group and is selected from H, Ci-C₆ alkyl which is unsubstituted or substituted, C₃-Ci₀ cycloalkyl, (CHa)_nO-Ci-C₆ alkyl which is unsubstituted or substituted, (CH₂)_πO(CH₂)_nAr², (CH₂)_nCO₂-Ci-C₆ alkyl which is unsubstituted or substituted and (CH₂)_nAr²; _.

Ar² is the same or different when more than one is present within a given substituent group and is an unsaturated C₆-Ci₀ membered carbocyclic group or an unsaturated 5-11 membered heterocycle, either of which is unsubstituted or substituted by one or more groups selected from Ci-C₆ alkyl, (CH₂)_nOR¹², halogen, nitro, CN, CO₂R¹², C(O)NR¹⁰R¹¹, NR¹²C(O)R¹², NR¹⁰R¹¹, SR¹², O(CH₂)_nC(O)NR¹⁰R^π, S(O)₂NR¹⁰R¹¹ and NR¹²S(O)₂R¹², or two adjacent atoms may be substituted by a methylenedioxy or an ethylenedioxy group;

R¹⁰ and R¹¹ which are the same or different are selected from H, C₁-C₆ alkyl which is unsubstituted or substituted, (CH₂)_nC₃-C₁₀ cycloalkyl, (CH₂)_nCO₂R¹² and (CH₂)_nOR¹², or R¹⁰ and R¹¹ together with the nitrogen atom to which they are attached, form a saturated five or six membered nitrogen containing heterocyclic ring, which may contain one extra heteroatom selected from O, N and S and which is unsubstituted or substituted; and R¹², which is the same or different when more than one is present within a given substituent group is selected from H, C₁-C₆ alkyl which is unsubstituted or substituted, C₃-Ci₀ cycloalkyl, (CH₂)_nO-Ci-C₆ alkyl which is unsubstituted or substituted, and (CH₂)_nCO₂-Ci-C₆ alkyl which is unsubstituted or substituted.

An unsaturated 5-,6- or 7-membered carbocyclic ring in the definition of P is a carbocyclic ring which, including the adjacent bond of the unsaturated ring to which it is fused, contains at least one unsaturated bond. The ring is aromatic or non-aromatic. Examples include cyclopentyl, cyclopentadienyl, phenyl and cycloheptenyl. Most preferably the ring is an unsaturated C₆- carbocyclic ring, typically phenyl. When this ring is substituted it is typically substituted as specified above for an unsaturated C₆- Ci₀ carbocyclic group.

An unsaturated 5-11 -membered heterocyclic group may be, for example, furan, thiophene, pyrrole, indole, isoindole, pyrazole, imidazole, benzothiphene, benzothiazole, benzofuran, isoxazole, oxazole, oxadiazole, thiazole, isothiazole, thiadiazole, dihydroimidazole, pyridine, quinoline, isoquinoline, quinoxaline, thienopyrazine, pyran, pyrimidine, phthalimide, pyridazine, pyrazine, purine, triazine, trizole, tetrazole, 1,3,4,5- tetramethyl-l,5-dihydropyrrol-2-one or uracil. In the definitions of Ar¹ and Ar² above this heterocyclic group is typically selected from pyridine, indole, thiophene, quinoline, isoquinoline, benziothiazole, pyrazole, benzofuran, pyrimidine, benzothiophene, pyrrole, imidazole and thiazole. When an unsaturated 5-11 membered heterocyclic group is substituted it is typically substituted as specified above for an unsaturated C₆-Ci₀ carbocyclic group.

An unsaturated 5-, 6- or 7-membered heterocyclic group may be selected from ^'■" suitable examples of a 5- to 11 -membered heterocyclic group as defined above. In the definition of P the group is preferably a 6-membered heterocyclic group, as for instance in the definition of P2. When P is substituted it is typically substituted by a 5-, 6- or 7-membered unsaturated heterocyclic group which is typically selected from thiazole, triazole, oxadiazole, imidazole, pyrimidine, dihydroimidazole, pyridine, pyrrole, pyrazole, indole, furan and dihydroimidazole.

When an unsaturated 5-, 6- or 7- membered carbocyclic or heterocyclic ring is substituted it is preferably substituted by Ci-C₆ alkyl which is unsubstituted or substituted, OR⁶, halogen, nitro, CN, CO₂R⁶, (CH₂)_nCONR⁴R⁵, (CH₂)_nNHCOR⁶, NR⁴R⁵, SO₂NR⁴R⁵, (CH₂)_nNHSO₂R⁶, (CH₂)_nC(O)R⁶ or NHCONR⁴R⁵, wherein R⁴, R⁵ and R⁶ are as defined above; or by imidazole which is unsubstituted or substituted, imidazolide which is unsubstituted or substituted, oxadiazole which is unsubstituted or substituted, amidoxime or amidine.

In a first preferred aspect of the invention the pyrrolopyrimidine is of formula (Ia)

wherein R¹, R² and R³ are as defined above; and Pl is an unsaturated C₆- carbocyclic group which is unsubstituted or substituted.

More preferably in this first aspect, the pyrrolopyrimidine is of formula (Ia')

wherein R¹, R² and R³ are as defined above and R¹³ and R¹⁴ are selected from H, C₁-C₆ alkyl which is unsubstituted or substituted, OR⁶, halogen, nitro, CN, CO₂R⁶, (CH₂)_nCONR⁴R⁵, (CH₂)_nNHCOR⁶, NR⁴R⁵, SO₂NR⁴R⁵, (CH₂)_nC(O)R⁶, (CH₂)_nNHSO₂R⁶, NHCONR⁴R⁵, imidazole which is unsubstituted or substituted, imidazolide which is unsubstituted or substituted, oxadiazole which is unsubstituted or substituted, amidoxime and amidine, wherein R⁴, R⁵ and R⁶ are as defined above.

In a second preferred aspect of the invention the pyrrolopyrimidine is of formula (Ib)

wherein R¹, R² and R³ are as defined above; and

P2 is an unsaturated 6-membered heterocyclic group which contains one nitrogen atom and which is unsubstituted or substituted. More preferably in this second aspect, the pyrrolopyrimidine is of formula (Ib')

wherein R¹, R² and R³ are as defined above and R¹⁵ is selected from H, C₁-C₆ alkyl, OR⁶, halogen, CN, CONR⁴R⁵ OrNR⁴R⁵, wherein R⁴, R⁵ and R⁶ are as defined above. In formulae (I), (Ia), (Ia'), (Ib) and (Ib'), R¹ is preferably H, Ci- C₆ alkyl

(especially CH₃), CH₂NR¹⁰R¹¹ (especially morpholin-4-ylmethyl), CH₂OR¹², CH₂CN₅ l O CH₂N₃, CH₂NHC(O)R¹², CH₂NHS(O)₂R¹² pyridinyl, (especially pyridin-2-yl) or -CH₂- imidazole, wherein R¹⁰, R¹¹ and R¹² are as defined above. More preferably R¹ is H, CH₃, moφholin-4-ylmethyl, CH₂NR¹⁰R¹¹ or CH₂OR¹² wherein R¹⁰, R¹¹ and R¹² are as defined above. Most preferably R¹ is H or moφholin-4-ylmethyl.

R² is preferably C₁- C₆ alkyl substituted by a quinoline group (especially quinolin- 15 4-ylmethyl) or Ci- C₆ alkyl substituted by phenyl (especially 2-phenyl-ethyl) wherein the phenyl is unsubstituted or substituted by halogen or nitro. More preferably, R² is 2- phenylethyl wherein the phenyl ring is substituted by one or more halogens. For instance, R² is (3,4-difluoro-phenyl)ethyl.

R³ is preferably H, CH₂Ar², (CHa)₂Ar², CH₂C(O)OR¹², CH₂CN, CH₂C(O)NR⁷R⁸ 0 or C₁-C₆ alkyl which is unsubstituted or substituted, wherein Ar², R⁷ and R^8' are as defined above. More preferably, R³ is H, Ci-C₆ alkyl which is unsubstituted or substituted, or CH₂Ar². Most preferably R³ is H or CH₃. Examples of the preferred compounds of the invention are:

Compounds of Formula (I) may be prepared by a process which comprises reacting a compound of Formula (II)

wherein R¹, R³ and P are as defined above for formula (I), with a compound of formula (III)

(in)

wherein R² is as defined above for formula (I), in an organic solvent in the presence of a base. The solvent is typically an aprotic solvent, for example N,N-dimethylformamide or acetonitrile. Alternatively it is a protic solvent, typically an alcohol, for example isopropanol. The reaction is typically conducted at an elevated temperature, for instance with warming. The reaction may, for example, be carried out at the reflux temperature of the solvent. The preferred temperature range for the reaction is 80-150⁰C. The base may be an organic amine, typically a tertiary amine, for example triethylamine. Alternatively the base may be an inorganic carbonate, typically an alkali metal or alkaline earth metal carbonate, for example potassium carbonate. Compounds of formula (III) are prepared using standard chemistry and are described in the reference examples which follow.

If desired one compound of formula (II) may be converted into another compound of formula (II).

For example a compound of formula (IΪ) may be nitrated using standard nitration conditions. A compound of formula (II) may be brominated using standard bromination conditions. A chlorosulphonyl group may be introduced to a compound of formula (II) using chlorosulphonic acid. A compound of formula (II) containing a chlorosulphonyl group may be converted into a chlorosulphonamide group by reaction with the appropriate amine. A compound of formula (II) may be prepared from a compound of formula (IV)

wherein R¹, R³ and P are as defined above, by treatment with a chlorinating agent. Suitable chlorinating agents include phosphorous oxychloride, thionyl chloride and sulphuryl chloride. The reaction is typically conducted with warming. The reaction may for example be carried out at the reflux temperature of the solvent. The preferred temperature range for the reaction is 80-150⁰C.

If desired one compound of formula (IV) may be converted into another compound of formula (IV). For example a compound of formula (IV) containing a haloalkyl group may be displaced by an appropriate nucleophile. A compound of formula (IV) may be nitrated using standard nitration conditions. A compound of formula (IV) containing a nitrile group may be hydrolysed to the corresponding carboxylic acid by using standard hydrolysis condition. A compound of formula (IV) containing a carboxylic acid group may be converted into an amide group by reaction with an amine in the presence of a coupling reagent.

A compound of formula (IV), where R¹ is H, may be prepared from a compound of formula (V)

wherein R³ and P are as defined above and R¹⁶ is C₁-C₆ alkyl, by treatment with ammonia in an organic solvent. The reaction is typically conducted with warming. The reaction may for example be carried out at the reflux temperature of the solvent. The preferred temperature is from 60⁰C -200⁰C. The solvent is preferably a protic solvent, typically an alcohol, for example ethanol.

A compound of formula (IV), where R¹ is other than H, may be prepared from a compound of formula (VI) by treatment with R¹CN and hydrogen chloride in an organic solvent. The solvent is preferably an aprotic solvent, for example dioxane. The reaction is typically conducted without warming. The preferred temperature range for the reaction is from O⁰C -5O⁰C.

A compound of formula (V) may be prepared from a compound of formula (VI)

by treatment with dimethylformamide dimethyl acetal in an organic solvent. The solvent is preferably an aprotic solvent, for example N,N-dimethylformamide. The reaction is typically conducted with warming. The reaction may for example be carried out at the reflux temperature of the solvent. The preferred temperature range for the reaction is 80⁰C -15O⁰C.

Compounds of formula (VI) are prepared using standard chemistry and are described in the reference examples which follow. If desired one compound of formula (I) may be converted into another compound of formula (I) by conventional methods.

For example, a compound of formula (I) containing a nitrile group maybe converted into a compound of formula (I) containing either an acid group or a primary amide group by acid or alkali hydrolysis. Alternatively a compound of the invention containing a nitrile group may be converted into a compound of the invention containing a primary amide group by treatment with hydrogen peroxide and sodium hydroxide. A compound of formula (I) may be nitrated on an activated aromatic ring, by using standard nitration conditions.

A compound of formula (I) containing a carboxylic acid may be converted into a compound of formula (I) containing an ester group by using standard esterification conditions.

A compound of formula (I) containing an ester group may be converted into a compound of formula (I) containing a carboxylic acid group by using standard hydrolysis conditions. A compound of formula (I) containing a secondary amine group may be converted into a compound of formula (I) containing a tertiary amine group by treatment with an alkyl halide in the presence of base, or alternatively by using reductive amination conditions with the appropriate carbonyl containing compound.

A compound of formula (I) containing a primary amide group may be converted into a compound of formula (T) containing a secondary amide group by treatment with an aldehyde in the presence of triethylsilane and trifluoroacetic acid. (Tet. Lett. 40 (1999), pp2295-2298).

A compound of formula (T) containing a primary amide group may be converted into a compound of formula (I) containing a secondary amide group by treatment with an aryl halide using a palladium catalyst (Org Lett 2000 ppl 101-1104). A compound of formula (T) containing an acidic NH group may be alkylated by treatment with an alkyl halide using an appropriate base, such as sodium hydride. A compound of formula (I) containing a nitro group maybe converted into a compound of formula (I) containing a primary amine group by reduction. A compound of formula (I) containing a carboxylic acid group may be converted into a compound of formula (T) containing an amide group by treatment with an amine and a coupling reagent such as 1 , 1 -carbonyldiimidazole.

A compound of formula^' (I) containing a primary or secondary amine group may be converted into a compound of formula (I) containing an amide, sulphonamide or urea group by treatment with an acyl chloride, a sulphonyl chloride or an isocycante respectively.

A compound of formula (I) containing an ester group may be converted into a compound of formula (I) containing an amide group by treatment with an amine at an elevated temperature. A compound of formula (I) containing a nitrile group may be converted into a compound of formula (I) containing an imidazolide group by treatment with a 1,2- diamine. The imidazolide may then be converted into the corresponding imidazole group by treatment with palladium on carbon.

A compound of formula (I) containing a nitrile group may be converted into a compound of formula (I) containing a primary amine group by using standard reduction conditions.

A compound of formula (T) containing a nitrile group may be converted into a compound of formula (T) containing an amidoxime group by treatment with hydroxylamine. A compound of formula (T) containing an amidoxime group may be converted into a compound of formula (I) containing an oxadiazole group by treatment with an acid chloride.

A compound of formula (T) containing a nitrile group may be converted into a compound of formula (T) containing an alkyl ketone group by treatment with a Grignard reagent. A compound of formula (I) containing a primary amine group may be converted into a compound of formula (I) containing a secondary amine group by reductive amination.

A compound of formula (I) in which the carbon atom adjacent to a pyridyl nitrogen is substituted by chlorine, may be reacted with a primary or secondary amine, to provide a compound of formula (I) containing an alpha-amino pyridyl group.

A compound of formula (T) in which the carbon atom adjacent to a pyridyl nitrogen is substituted by chlorine, may be reacted with an alkyl zinc chloride, to provide a compound of formula (I) containing an alpha-alkyl pyridyl group. Pyrrolopyrimidines of formulae (I), (Ia), (Ia'), (Ib) and (Ib') may be converted into pharmaceutically acceptable salts, and salts may be converted into the free compound, by conventional methods. Pharmaceutically acceptable salts include salts of inorganic acids such as hydrochloric acid, hydrobromic acid and sulphuric acid, and salts of organic acids such as acetic acid, oxalic acid, malic acid, methanesulfonic acid, trifluoroacetic acid, benzoic acid, citric acid and tartaric acid. In the case of compounds of the invention bearing a free carboxy substituent, the salts include both the above- mentioned acid addition salts and the salts of sodium, potassium, calcium and ammonium. The latter are prepared by treating the free pyrrolopyrimidine of formula 1 , or the acid addition salt thereof, with the corresponding metal base or ammonia. Cancer cells which exhibit multi-drug resistance, referred to as MDR cells, display a reduction in intracellular drug accumulation compared with the corresponding drug-sensitive cells, corresponding drug-sensitive cells. Multidrug resistance is conferred by two different integral membrane proteins, the 17OkDa P-glycoprotein (Pgp) and the 19OkDa multidrug resistance protein (MRP). MDR is often associated with increased expression of the plasma membrane glycoprotein (P-gp) which, has drug binding properties. P-gp is thought to function as an efflux pump for many hydrophobic compounds, and transfection studies using cloned P-gp have shown that its overexpression can confer the MDRphenotype on cells: see, for example, Ann. Rev. Biochem 58 137-171 (1989). MRP is widely distributed in normal tissues including peripheral blood, endocrine glands (adrenal and thyroid), striated muscle, lymphoreticular tissues (spleen and tonsil), tissues from the digestive tract (salivary gland, oesophagus, liver, gall bladder, pancreas and colon), respiratory tract (lung) and urogenital tract (kidney, bladder, testis, and ovary).

ABC transporters such as MRP play an essential role in defending against toxic compounds. MRPl gene knockout mice (-/-) are hypersensitive to etoposide (Wijnholds J, Evers R, van Leusden MR, MoI CAAM, Zaman GJR, Mayer U, Beijnen JH, van der VaIk M, Krimpenfort P, Borst P (1997) Increased sensitivity to anticancer drugs and decreased inflammatory response in mice lacking MRP. Nat. Med. Ih 1275-1279) and this is especially seen in bone marrow, testis, kidney, the oropharyngeal mucosa - cells with a substantial MRP content (Wijnholds J, Scheffer M, van der VaIk M, Beijnen JH, Scheper RJ, Borst P (1998) MRP protects the oropharyngeal mucosal layer and the testicular tubules against drug induced damage. J. Exp. Med. 188: 797-808).

Some insight into the normal physiological role of MRP has also been obtained by the demonstration that membrane vesicles from MRP-overexpressing drug-selected and transfected cells support ATP-dependent transport of the cysteinyl leukotriene, LTC₄

(Loe DW, Almquist KC, Deeley RG, Cole SPC. (1996) MRP-mediated transport OfLTC₄ and chemotherapeutic agents in membrane vesicles. J Biol Chem 271 9675-9682). The cysteinyl leukotrienes (LTC₄, LTD4 and LTE4) are potent mediators of inflammation that increase vascular permeability and smooth muscle contraction. LTC₄ is derived from arachidonic acid in a series of reactions that result in conjugation of glutathione and LTA₄ by LTC₄ synthase. It is then exported from the cell by MRP. LTC₄ is actively transported across the plasma membrane by MRP, and extracellularly LTD4 and LTE4 are formed by the action of γ- glutamyl transpeptidase and dipeptidase, respectively (Leier J, Jedlitschky G, Buchholz U, Cole SP, Deeley RG, Keppler D (1994). The MRP gene encodes an ATP-dependent export pump for Leukotriene C₄ and structurally related conjugates. J. Biol. Chem. 269: 27807-27810). LTC₄ synthase and MRP are both expressed in eosinophils and mast cells; these cell types play a pivotal role in asthma by IgE-mediated synthesis and release of cysteinyl leukotrienes.

Inhibition of MRP-mediated transport is being targeted as a mechanism for reversing resistance to cytotoxic drugs in different cancers (a multidrug resistance modulator). Inhibition OfLTC₄ transport by MRP may prevent associated inflammation and bronchoconstriction, for example in asthma (LTC₄ efflux inhibitor).

The human MRP family has at least nine members, including MRPl, MRP2 and MRP3. MRPs are organic anion transporters, meaning that they transport anionic drugs (such as methotrexate) and neutral drugs conjugated to acidic ligands (such as glutathione, glucuronate and sulphate). Drugs, such as anticancer drugs, may also be transported alongside free glutathione.

The ubiquitous nature of MRPl in normal human tissues implies that it is , potentially also present in most tumours. In fact, MRPl protein or mRNA has been detected in most types of tumour examined including solid tumours and haematological malignancies.

Compounds of the invention have been found in biological tests to have activity as inhibitors of MRP. Compounds of the invention have also been found to be selective for MRP over P-gp with a range of selectivity from about 20-fold to greater than 200- fold. A compound of the present invention may thus be used as an inhibitor of MRP, in particular MRPl. A compound of the present invention may also be used as an LTC₄ efflux inhibitor. The present compounds can be used to modulate MDR, hi particular MRP-mediated MDR. The present compounds may thus be used as multi-drug resistance modifying agents, also termed resistance-modifying agents, or RMAs. The present compounds can modulate, e.g. reduce, or eliminate multi-drug resistance, especially that which is MRP mediated.

The present compounds can be used hi a method of potentiating the cytotoxicity of a chemotherapeutic agent. Such a method comprises, for instance, administering one of the present compounds to the tumour cell whilst the tumour cell is exposed to the chemotherapeutic agent in question. The therapeutic effect of a chemotherapeutic, or antineoplastic, agent may thus be enhanced. The multi-drug resistance of a tumour cell to a chemotherapeutic agent during chemotherapy may be reduced or eliminated.

The present compounds can also be used in a method of treating a disease in which the responsible pathogen exhibits multi-drug resistance, especially MRP-mediated MDR multi-drug resistance, for instance multi-drug resistant forms of malaria {Plasmodium falciparum), tuberculosis, leishmaniasis and amoebic dysentery. Such a method comprised, for instance, administering one of the present compounds with (separately, simultaneously or sequentially) the drug to which the pathogen concerned exhibits multi-drug resistance. The therapeutic effect of a drug directed against a multidrug resistant pathogen may thus be potentiated.

Leukotrienes, such as LTC₄, are also considered important for antibacterial defence. In the lung it has been shown that mice lacking MRPl are resistant to pneumonia (J. Immunol. 2001, pp 4059-64; Schultz MJ et aT). These results suggest that inhibition of MRPl may have benefit in therapy for diseases such as pneumonia. According, one of the present compounds may be used to treat a bacterial infection, for instance pneumonia.

Inhibition of MRP may also be of benefit in the management of epilepsy. In a recent study MRPl was found to be over-expressed in human brain tissue containing focal cortical dysplasia, the most common malformation causing refractory epilepsy (The Lancet 2001, vol 357 no. 9249, p. 42 Sisodiya et at). Over-expression of MRPl could have a major effect on the drug responsiveness in epilepsy and inhibition of MRPl in refractory epilepsy may offer an alternative treatment strategy. Accordingly, one of the present compounds may be used to treat a patient suffering from epilepsy.

A human or animal patient harbouring a tumour may be treated for resistance to a chemotherapeutic agent by a method comprising the administration thereto of one of the present compounds. The present compound is administered in an amount effective to potentiate the cytotoxicity of the said chemotherapeutic agent. Examples of chemotherapeutic or antineoplastic agents which are preferred in the context of the present invention include mitoxantrone; vinca alkaloids such as vincristine and vinblastine; anthracycline antibiotics such as daunorubicin and doxorubicin; alkylating agents such as chlorambucil and melphalan; taxanes such as paclitaxel; antifolates such as methotrexate and tomudex; epipodophyllotoxins such as etoposide; and camptothecins such as irinotecan and its active metabolite SN-38. There is also some evidence linking expression of MRP, in particular MRP2, with resistance to platinum-containing compounds such as cisplatin. Further, there is evidence linking expression of MRP, in particular MRP4 and MRP5, with resistance to nucleotide analogues such as 6- mercaptopurine and 6-thioguanine.

The present compounds may also be used in a method of enhancing the absorption, distribution, metabolism and/or elimination characteristics of a therapeutic agent, which method comprises administering to a patient, separately, simultaneously or sequentially, one of the present compounds and the said therapeutic agent. In particular this method may be used to enhance the penetration of the therapeutic agent into the central nervous system, or to enhance the oral absorption of the therapeutic agent. For instance, the present compounds can be used in a method of facilitating the delivery of drugs across the blood brain barrier, and in the treatment of ADDS or AIDS related complex. A human or animal patient in need of such treatment may be treated by a method comprising the administration thereto of one of the present compounds.

The present compounds may also be used in a method of treating a multidrug resistant tumour, especially a tumour in which the multidrug resistance is MRP mediated. Examples of such tumours include solid tumours, for instance lung, gastrointestinal and urothelial carcinomas, neuroblastoma, glioma, retinoblastoma, melanoma, cancers of the breast, endometrium, ovary, prostate and thyroid, and haematological malignancies. The condition of a patient harbouring a tumour may thus be ameliorated by the administration thereto of one of the present compounds. The present compounds can also be used in a method of treating inflammation or bronchoconstriction, for instance asthma. Also, the present compounds may be used to treat HIV infection. HIV protease inhibitor drugs, for instance ritonavir and saquinavir, are substrates for MRP. Elevated levels of MRP at sites of viral replication can reduce the accumulation of HIV inhibitors, resulting in lower intracellular drug concentrations. The inhibition of MRP by compounds of the invention can thus overcome this problem.

The present compounds can be administered in a variety of dosage forms, for example orally such as in the form of tablets, capsules, sugar- or film-coated tablets, liquid solutions or suspensions or parenterally, for example intramuscularly, intravenously or subcutaneously. The present compounds may therefore be given by injection or infusion. The dosage depends on a variety of factors including the age, weight and condition of the patient and the route of administration. Typically, however, the dosage adopted for each route of administration when a compound of the invention is administered alone to adult humans is 0.001 to 500 mg/kg, most commonly in the range of 0.01 to 100 mg/kg, body weight, for instance 0.01 to 50 mg/kg. Such a dosage may be given, for example, from 1 to 5 times daily by bolus infusion, infusion over several hours and/or repeated administration.

A pyrrolopyrimidine of formula (I) or a pharmaceutically acceptable salt thereof is formulated for use as a pharmaceutical or veterinary composition also comprising a pharmaceutically or veterinarily acceptable carrier or diluent. The compositions are typically prepared following conventional methods and are administered in a pharmaceutically or veterinarily suitable form. An agent for use as a modulator of multi-drug resistance comprising any one of the present compounds is therefore provided. The present compounds may be administered in any conventional form, for instance as follows:

A) Orally, for example, as tablets, coated tablets, dragees, troches, lozenges, aqueous or oily suspensions, liquid solutions, dispersible powders or granules, emulsions, hard or soft capsules, or syrups or elixirs. Compositions intended for oral use may be prepared according to any method known in the art for the manufacture of pharmaceutical compositions and such compositions may contain one or more agents selected from the group consisting of sweetening agents, flavouring agents, colouring agents and preserving agents in order to provide pharmaceutically elegant and palatable preparations. Tablets contain the active ingredient in admixture with non-toxic pharmaceutically acceptable excipients which are suitable for the manufacture of tablets. These excipients may be for example, inert diluents, such as calcium carbonate, sodium carbonate, lactose, dextrose, saccharose, cellulose, corn starch, potato starch, calcium phosphate or sodium phosphate; granulating and disintegrating agents, for example, maize starch, alginic acid, alginates or sodium starch glycolate; binding agents, for example starch, gelatin or acacia; lubricating agents, for example silica, magnesium or calcium stearate, stearic acid or talc; effervescing mixtures; dyestuffs, sweeteners, wetting agents such as lecithin, polysorbates or lauryl sulphate. The tablets may be uncoated or they may be coated by known techniques to delay disintegration and adsorption in the gastrointestinal tract and thereby provide a sustained action over a longer period. For example, a time delay material such as glyceryl monostearate or glyceryl distearate may be employed. Such preparations may be manufactured in a known manner, for example by means of mixing, granulating, tableting, sugar coating or film coating processes.

Formulations for oral use may also be presented as hard gelatin capsules wherein the active ingredient is mixed with an inert solid diluent, for example, calcium carbonate, calcium phosphate or kaolin, or as soft gelatin capsules wherein the active ingredient is present as such, or mixed with water or an oil medium, for example, peanut oil, liquid paraffin, or olive oil.

Aqueous suspensions contain the active materials in admixture with excipients suitable for the manufacture of aqueous suspensions. Such excipients are suspending agents, for example, sodium carboxyrnethylcellulose, methylcellulose, hydroxypropylmethyl-cellulose, sodium alginate, polyvinylpyrrolidone gum tragacanth and gum acacia; dispersing or wetting agents may be naturally-occurring phosphatides, for example lecithin, or condensation products of an alkylene oxide with fatty acids, for example polyoxyethylene stearate, or condensation products of ethylene oxide with long chain aliphatic alcohols, for example heptadecaethyleneoxycetanol, or condensation products of ethylene oxide with partial esters derived from fatty acids and a hexitol such as polyoxyethylene sorbitol monooleate, or condensation products of ethylene oxide with partial esters derived from fatty acids and hexitol anhydrides for example polyoxyethylene sorbitan monooleate. The said aqueous suspensions may also contain one or more preservatives, for example, ethyl or n-propyl p-hydroxybenzoate, one or more colouring agents, such as sucrose or saccharin.

Oily suspension may be formulated by suspending the active ingredient in a vegetable oil, for example arachis oil, olive oil, sesame oil or coconut oil, or in a mineral oil such as liquid paraffin. The oily suspensions may contain a thickening agent, for example beeswax, hard paraffin or cetyl alcohol. Sweetening agents, such as those set forth above, and flavouring agents may be added to provide a palatable oral preparation. These compositions may be preserved by this addition of an antioxidant such as ascorbic acid. Dispersible powders and granules suitable for preparation of an aqueous suspension by the addition of water provide the active ingredient in admixture with a dispersing or wetting agent, a suspending agent and one or more preservatives. Suitable dispersing or wetting agents and suspending agents are exemplified by those already mentioned above. Additional excipients, for example sweetening, flavouring and colouring agents, may also be present.

The pharmaceutical compositions of the invention may also be in the form of oil- in-water emulsions. The oily phase may be a vegetable oil, for example olive oil or arachis oils, or a mineral oil, for example liquid paraffin or mixtures of these. Suitable emulsifying agents may be naturally-occurring gums, for example gum acacia or gum tragacanth, naturally occuring phosphatides, for example soy bean lecithin, and esters or partial esters derived from fatty acids an hexitol anhydrides, for example sorbitan mono- oleate, and condensation products of the said partial esters with ethylene oxide, for example polyoxyethylene sorbitan monooleate. The emulsion may also contain sweetening and flavouring agents. Syrups and elixirs may be formulated with sweetening agents, for example glycerol, sorbitol or sucrose. In particular a syrup for diabetic patients can contain as carriers only products, for example sorbitol, which do not metabolise to glucose or which only metabolise a very small amount to glucose.

Such formulations may also contain a demulcent, a preservative and flavouring and coloring agents;

B) Parenterally, either subcutaneously, or intravenously, or intramuscularly, or intrasternally, or by infusion techniques, in the form of sterile injectable aqueous or oleaginous suspensions. This suspension may be formulated according to the known art using those suitable dispersing of wetting agents and suspending agents which have been mentioned above. The sterile injectable preparation may also be a sterile injectable solution or suspension in a non-toxic paternally-acceptable diluent or solvent, for example as a solution in 1,3-butane diol. Among the acceptable vehicles and solvents that may be employed are water,

Ringer's solution and isotonic sodium chloride solution, hi addition, sterile, fixed oils are conventionally employed as a solvent or suspending medium. For this purpose any bland fixed oil may be employed including synthetic mono- or diglycerides. In addition fatty acids such as oleic acid find use in the preparation of injectables;

C) By inhalation, in the form of aerosols or solutions for nebulizers; D) Rectally, in the form of suppositories prepared by mixing the drug with a suitable non-irritating excipient which is solid at ordinary temperature but liquid at the rectal temperature and will therefore melt in the rectum to release the drug. Such materials are cocoa butter and poly-ethylene glycols;

E) Topically, in the form of creams, ointments, jellies, collyriums, solutions or suspensions.

Daily dosages can vary within wide limits and will be adjusted to the individual requirements in each particular case, rn general, for administration to adults, an appropriate daily dosage is in the range of about 5 mg to about 500 mg, although he upper limit may be exceeded if expedient. The daily dosage, can be administered as a single, dosage or in divided dosages.

The following examples illustrate the invention.

Reference Example 1: Preparation of Compounds of General Formula (VD

Reference Example 1 A: 3-Amino-lH-indole-2-carboxylic acid ethyl ester

3-Amino-lH-indole-2-carboxylic acid ethyl ester was prepared from N-(2- cyanophenyl)glycine ethyl ester using potassium tert-butoxide in THF as described in the literature (J. Het. Chem, 20, 1983, pp495-499)

Reference Example IB

3-Amino-4-cvano-indole-l,2-dicarboxylic acid 1-tert-butyl ester 2-ethyl ester A mixture of 3-fluoro-l,2-cyanobenzene (2.49g), glycine ethyl ester hydrochloride (2.49g) and potassium carbonate (5.18g) in acetonitrile (25mL) was heated to reflux for 24 hours. After cooling, the reaction mixture was extracted into dichloromethane, washed with water, dried (MgSO₄) and the solvent removed in vacuo to yield crude product which was purified using flash chromatography to yield (2,3-dicyano-phenylamino)- acetic acid ethyl ester (840mg).

A mixture of (2,3-dicyano-phenylamino)-acetic acid ethyl ester (453mg), triethylamine (0.24mL), di-tert-butyl dicarbonate (447mg) and 4-dimethylaminopyridine (20mg) was stirred in dichloromethane (5mL) at room temperature overnight. The reaction mixture was then extracted into dichloromethane, washed with water, dried (MgSO₄) and the solvent removed in vacuo to yield crude product which was purified using flash chromatography to yield the title compound (60όmg).

Reference Example 1C

3-Arnino-indole-l,2,5-tricarboxylic acid 1-tert-butyl ester 2-ethyl ester 5-methyl ester A mixture of 2-fluoro-5-formylbenzonitrile (9.22g) and pyridinium dichromate (46.52g) in dimethylformamide (9OmL) was stirred at room temperature overnight. The reaction mixture was then extracted into ethyl acetate, washed with water, dried (MgSO₄) and the solvent removed in vacuo to yield 3-cyano-4-fluoro-benzoic acid (8.2Ig) To 3-cyano-4-fluoro-benzoic acid (8.2Ig) in methanol (8OmL) was added acetyl chloride (14mL) and the reaction mixture was stirred at room temperature for 2 days. The solution was reduced in vacuo yielding a precipitate which was collected by filtration to yield 3- cyano-4-fluoro-benzoic acid methyl ester as a white solid (7.25g)

A mixture of 3-cyano-4-fluoro-benzoic acid methyl ester (7.25g), glycine ethyl ester hydrochloride (5.94g) and potassium carbonate (14g) in acetonitrile (7OmL) was heated to reflux for 24 hours. After cooling, the reaction mixture was extracted into dichloromethane, washed with water, dried (MgSO₄) and the solvent removed in vacuo to yield crude product which was purified using flash chromatography to yield the 3-cyano- 4-(ethoxycarbonyhnethyl-amino)-benzoic acid methyl ester (4.49mg). A mixture of 3-cyano-4-(ethoxycarbonylmethyl-amino)-benzoic acid methyl ester (500mg), triethylamine (0.27mL), di-tert-butyl dicarbonate (502mg) and 4- dimethylaminopyridine (20mg) was stirred in dichloromethane (5mL) at room temperature overnight. The reaction mixture was then extracted into dichloromethane, washed with water, dried (MgSO₄) and the solvent removed in vacuo to yield the title compound (476mg).

Reference Example ID S-Amino^-chloro-lH-indole-l-carboxylic acid ethyl ester

A mixture of 2-chloro-6-fluorobenzonitrile (5.18g), glycine ethyl ester hydrochloride (6.9g) and potassium carbonate (2.2 equivalents) was heated to 100⁰C in DMSO (8OmL) for 5 hours. The reaction mixture was then cooled, quenched with water, extracted into ethyl acetate and the solvent removed in vacuo to yield crude product which was purified using flash chromatography (2. Ig) to yield N-(3-chloro-2-cyanophenyl) glycine ethyl ester.

A mixture of N-(3-chloro-2-cyanophenyl) glycine ethyl ester (2.Ig) and potassium tert- butoxide (1.04g) was stirred in dry tetrahydrofuran (1OmL) overnight. Aqueous work-up yielded the desired title compound (1.27g)

Reference Example IE l-Acetyl-S-amino^-nitro-lH-indole-Σ-carboxylic acid ethyl ester

Concentrated hydrochloric acid (1.5mL) was added dropwise to a refluxing solution of

2,6-dinitrobenzonitrile (500mg) in methanol (1OmL) and dioxane (6.5mL). To this was added iron powder (467mg) portionwise. After refluxing for 30 minutes, the reaction mixture was cooled and reduced in vacuo. The residue was triturated with water to yield 2-amino-6-nitrobenzonitrile as an orange solid.

To a solution of 2-amino-6-nitrobenzonitrile (163mg) and triethylamine (0.096mL) in tetrahydrofuran (5mL) was added acetyl chloride (0.085mL) carefully, followed by A- dimethylaminopyridine (catalytic) .The reaction mixture was stirred for 20 hours at room temperature and then diluted with ethyl acetate, washed with water, dried (MgSO₄) and the solvent removed in vacuo to yield N-(2-cyano-3-nitro-phenyl)acetamide (195mg). To a solution of N-(2-cyano-3-nitro-phenyl)acetamide (lOOmg) in dry tetrahydrofuran (1OmL) at O⁰C was added sodium hydride (46mg) and the mixture was stirred for 30 minutes. Ethyl bromoacetate (89mg) was added and the reaction mixture was stirred for 24 hours. The reaction mixture was quenched with water, extracted into ethyl acetate, dried (MgSO₄) and the solvent removed in vacuo to yield the title compound (82mg).

Reference Example IF 3 -Amino-4-fluoro-l -methyl- lH-indole-2-carboxylic acid ethyl ester

A mixture of 2,6-difluorobenzonitrile (5.Og), sarcosine ethyl ester hydrochloride (6.07g) and potassium carbonate (10.9g) in dimethylformamide (25mL) was heated to 8O⁰C for 2 days. The reaction mixture was then cooled, extracted into ethyl acetate, washed with water, dried (MgSO₄) and the solvent removed in vacuo to yield crude material which was purified using flash chromatography to yield the title compound (3.04g)

Reference Example IG

3-Amino-5-trifluoromethoxy-lH-indole-2-carboxylic acid ethyl ester

To a solution of aniline (0.74mL) in 20% hydrochloric acid at O⁰C was added a solution of sodium nitrite (0.57g) in water (2.2mL). This solution was then added dropwise to a solution of 5-trifluoromethoxy-lH-indole-2-carboxylic acid ethyl ester (commercially available, 2.Og) in dimethylformamide (3OmL). The pH was then adjusted to 7.5-8 by addition of dilute sodium carbonate solution. After 1.5 hours the precipitate was filtered off and washed with water to yield 3-phenylazo-5-trifluoromethoxy-lH-indole-2- carboxylic acid ethyl ester as a red solid (2.17g).

To a suspension of the 5-trifluoromethoxy-lH-indole-2-carboxylic acid ethyl ester (2.17g) in isopropanol (2OmL) was added concentrated hydrochloric acid (4.79mL) and tin (5 equiv). The reaction mixture was heated to reflux for 2.5 hours and then cooled. The tin residues were filtered off, and then further cooling of the filtrate resulted in the precipitation of the desired title compound which was collected by filtration (1.7Ig).

3-Arnino-5-methoxy-lH-indole-2-carboxylic acid ethyl ester was prepared in an analogous manner from 5-methoxy-lH-indole-2-carboxylic acid ethyl ester; 3-Amino-6-methoxy-lH-indole-2-carboxylic acid methyl ester was prepared in an analogous manner from 6-methoxy-lH-indole-2-carboxylic acid methyl ester. Reference Example IH

S-Amino-l-benzoyl^-methyl-lH-indole-Σ-carboxylic acid ethyl ester To a solution of 2-amino-6-methylbenzonitrile (9.05 g) in dichloromethane (18OmL) was added benzoyl chloride (9mL) and pyridine (1OmL). The reaction mixture was stirred at room temperature overnight and then quenched with water. The organic phase was collected, dried (MgSO₄) and the solvent removed in vacuo to yield N-(2-cyano-3- methyl-phenyl)-benzamide (15.6g)

To a solution of N-(2-cyano-3-methyl-phenyl)-benzamide (3.96g) in dimethylformamide (2OmL) was added caesium carbonate (8.2g) and ethyl bromoacetate (2.25mL). The reaction mixture was stirred at room temperature overnight and then diluted with ethyl acetate, washed with brine, dried (MgSO₄) and the solvent removed in vacuo to yield crude product. Purification using flash chromatography yielded the title compound (16.8g).

Reference Example H

S-Ammo^-cvano-l-memyl-lH-pyrrolofΣ.S-blpyridine-Σ-carboxylic acid ethyl ester 2-Chloro-3,4-dicyanopyridine was prepared as described in the literature (J. Het Chem., 1990, pp 1654, Lee et al). Reaction with sarcosine ethyl ester hydrochloride in dimethylformamide yielded [(3,4-dicyano-pyridin-2-yl)-methyl-amino]-acetic acid ethyl ester which was cyclised using caesium carbonate in acetonitrile to yield the title compound.

3-Amino-l,6-drmethyl-lH-pyrrolo[2,3-b]pyridine-2,4-dicarboxylic acid diethyl ester was prepared in analogous fashion from 2-chloro-3-cyano-6-methyl-isonicotinic acid ethyl ester.

Reference Example IJ

3 -Amino- 1 -benzyl-4-dimethylamino- 1 H-pyrrolor3 ,2-c]p yridine-2-carboxylic acid ethyl ester The title compound was prepared from 4-berizylamino-2-chloro-nicotinonitrile (Chem. Heterocycl. Compd. {Engl. Transl.} 19, 6, 1983, 657-661, Granik V.G et al) as described in the literature (Pharm. Chem. J. {Engl. Transl.} 1995, vol 29, ppl34, Evstratova et al)

2-CMoro-4-metiiylarnrno-nicotinonitrile was prepared by the method described by Granik et al with the use of methylamine. 3-Amino-4-chloro-l-methyl-lH-pyrrolo[3,2- c]pyridine-2-carboxylic acid ethyl ester was prepared from this compound using the method described by Evstratova et al, but the chloro group was retained by excluding the dimethylamine step. .

S-Amino-l-methyl-lH-pyrrolotS^-cjpyridme^-carboxylic acid ethyl ester was prepared from 3-ammo-4-cUoro-l-methyl-lH-pyrrolo[3,2-c]pyridine-2-carboxylic acid ethyl ester by treatment with palladium on carbon in ethanol under an atmosphere of hydrogen.

Reference Example IK l-Acetyl-S-arrrino-lH-pmolόp^-blpyridine^-carboxylic acid ethyl ester

N-Pyridin-3-yl-acetamide was prepared by treatment of 3-aminopyridine with acetyl chloride.

A solution of N-pyridin-3-yl-acetamide (150mg) in chloroform (2OmL) was treated with 3-chloroperbenzoic acid (470mg). After 6 hours the reaction mixture was reduced in vacuo. The residue was dissolved in water, washed with ether, and the aqueous layer was then reduced in vacuo to yield N-( 1 -oxy-pyridin-3-yl)-acetamide.

A solution of N-(l-oxy-pyridin-3-yl)-acetamide (1.Og) in dichloromethane (5OmL) was added to trimethylsilyl cyanide (1.05mL). To this solution was added N₅N- dimethylcarbamoyl chloride (0.72mL) and the mixture was stirred at room temperature for 24 hours. 10% aqueous K₂CO₃ was then added and stirred for 20 minutes. The organic layer was then collected, dried (MgSO₄) and the solvent removed in vacuo to yield N-(2-cyano-pyridin-3-yl)-acetamide (970mg)

Treatment of N-(2-cyano-pyridin-3-yl)-acetamide with ethyl bromoacetate using sodium hydride as base yielded the desired title compound. Reference Example 2: Preparation of Compounds of General Formula (V)

Reference Example 2A:

3-(Dimethylaimno-methylenearninoVlH-indole-2-carboxylic acid ethyl ester A mixture of 3-amino-lH-indole-2-carboxylic acid ethyl ester (0.63g), N₅N- dimethylformamide dimethyl acetal (0.53mL) and dimethylformamide (5mL) was heated to 100⁰C overnight. The mixture was then cooled and water added yielding a precipitate which was collected by filtration to yield the title compound as a yellow solid (0.43 g)

The following compounds of formula (V) were prepared in an analogous manner from the appropriate compound of formula (VI)

3-(Dimemylanimo-memylenearnino)-indole-l,2,5-tricarboxylic acid 1-tert-butyl ester 2- ethyl ester 5-methyl ester;

4-Cyano-3 -(dimethylamino-methyleneamino)-indole- 1 ,2-dicarboxylic acid 1 -tert-butyl ester 2-ethyl ester;

4-CMoro-3-(dimethylamino-methyleneamino)-lH-indole-2-carboxylic acid ethyl ester;

5-Memoxy-3-(dimemylamino-memylenearnino)-lH-indole-2-carboxylic acid ethyl ester;

5-Trifluoromemoxy-3-(dmiemylammo-methylenearnino)-lH-indole-2-carboxylic acid ethyl ester; 3-(Dimemylarnino-methylenearnino)-6-methoxy-lH-indole-2-carboxylic acid methyl ester;

3-(Dimemylamino-methyleneamino)-4-nitro-lH-mdole-2-carboxylic acid ethyl ester was prepared from l-acetyl-3-amino-4-nitro-lH-indole-2-carboxylic acid ethyl ester (acetyl group is cleaved at this stage); 3-(Dimemylammo-memyleneamino)-l-methyl-4-nitro-lH-indole-2-carboxylic acid ethyl ester was also prepared from l-acetyl-S-amino^-nitro-lH-indole^-carboxylic acid ethyl ester (at higher temperatures acetyl group is cleaved and indole nitrogen is methylated);

3 -(Dimethylamino-methyleneamino)-4-fluoro- 1 -methyl- 1 H-indole-2-carboxylic acid ethyl ester; 4-Cyano-3-(dimethylamino-methyleneamino)-l-methyl-lH-indole-2-carboxylic acid ethyl ester; 1 -Benzoyl-3-(dimethylamino-methyleneainino)-4-methyl- 1 H-indole-2-carboxylic acid ethyl ester;

4-Cyano-3 -(dimethylamino-methyleneamino)- 1 -methyl- 1 H-pyrrolo [2,3-b]pyridine-2- carboxylic acid ethyl ester; 3-(Dimethylamino-metiiyleneaπύno)-l,6-dimethyl-lH-pyrrolo[2,3-b]pyridine-2,4- dicarboxylic acid diethyl ester;

3-(Pimethylamino-methylenearnino)-l-methyl-lH-pyrrolo[3,2-c]pyridine-2-carboxylic acid ethyl ester;

1 -Benzyl-4-dime1iiylamino-3-(dimetliylaniirio-rnethylenearnino)- 1 H-pyrrolo [3 ,2- cjpyridine^-carboxylic acid ethyl ester; l-Ace1yl-3-(dimethylamino-methyleneanτino)-lH-pyrrolo[3,2-b]pyridine-2-carboxylic acid ethyl ester;

Reference Example 3: Preparation of Compounds of General Formula (TV) Reference Example 3A. (For compounds where Rl= H^*) 2,9-Dihvdro-2,4,9-triaza-fluoren-l-one

A saturated solution of ammonia in ethanol (10OmL) was prepared at 0⁰C and mixed with 3-(dimemylammo-metiiyleneamino)-lH-indole-2-carboxylic acid ethyl ester (0.42g). The mixture was heated to 11O⁰C in a sealed bomb overnight. The volatiles were removed in vacuo and the remaining solid was stirred in 10% aqueous sodium hydroxide solution for 30 minutes. Any solid persisting was removed by filtration. The filtrate was then neutralised to pH 7 using acetic acid and the precipitated solid collected by filtration to yield the title compound (0.27g)

The following compounds of formula (IV) were prepared in analogous manner from the appropriate compound of formula (V);

l-Oxo-2,9-dihydro-lH-2,4,9-triaza-fluorene-6-carboxylic acid methyl ester (note BOC group is cleaved during this step); l-Oxo-2,9-dihydro-lH-2,4,9-triaza-fluorene-5-carbonitrile (note BOC group is cleaved during this step); 5-Chloro-2,9-diliydro-2,4,9-triaza-fluoren- 1 -one;

5-Nitro-2,9-dihydro-2,4,9-triaza-fluoren-l-one;

9-Methyl-5-nitro-2,9-dihydro-2,4,9-triaza-fluoren-l-one;

5-Fluoro-9-methyl-2,9-dihydro-2,4,9-triaza-fluoren-l-one; 9-Methyl-l-oxo-2,9-dihydro-lH-2,4,9-triaza-fluorene-5-carbonitrile;

6-Methoxy-2,9-dihydro-2,4,9-triaza-fluoren- 1 -one;

6-Trifluoromethoxy-2,9-dihydro-2,4,9-triaza-fluoren-l -one;

7-Methoxy-2,9-dihydro-2,4,9-triaza-fluoren-l-one;

5-Methyl-2,9-dihydro-2,4,9-triaza-fluoren-l-one (benzoyl group cleaved in this step); 9-Methyl-8-oxo-8,9-dihydro-7H-l,5,7,9-tetraaza-fluorene-4-carbonitrile;

2,9-Dimethyl-8-oxo-8,9-dihydro-7H-l,5,7,9-tetraaza-fluorene-4-carboxylic acid amide

(note-ethyl ester is converted into primary amide in this step);

9-Benzyl-5-dinaethylarnino-2₃9-dihydro-2,4,6,9-tetraaza-fluoren-l-one ;

9-Methyl-2,9-dihydro-2,4,6,9-tetraaza-fluoren-l -one; 2,9-Dihydro-2,4,5,9-tetraaza-fluoren-l-one (note- acetyl group cleaved in this step);

Reference Example 3B. (For compounds where Rl^ H). 3-Chloromethyl-2,9-dihvdro-2,4,9-triaza-fluoren-l-one Reference method: Il Farmaco 54 (1999), pp.255-264 Hydrogen chloride gas was bubbled through a mixture of 3 -amino- 1 H-indole-2- carboxylic acid ethyl ester (3.0Og) and chloroacetonitrile (2.6ml) in dry 1,4-dioxane (40ml) at O⁰C for two minutes. The reaction mixture was then stirred at room temperature overnight. The reaction mixture was carefully diluted with ice/water and basified to pH~8 with 10% ammonium hydroxide, the precipitate collected by filtration, washed with water, dried to give the title compound as a beige solid (3.17g).

The following compounds of formula (IV) were prepared in an analogous manner from the appropriate compound of formula (VI) and the appropriate compound of formula RlCN 3-Methyl-2,9-dihydro-2,4,9-triaza-fluoren-l-one was prepared from 3-amino-lH-indole- 2-carboxylic acid ethyl ester and acetonitrile; 3-Pyridm-2-yl-2,9-dmydro-2,4,9-triaza-fluoren-l-one was prepared from 3-amino-lH- indole-2-carboxylic acid ethyl ester and 2-cyanopyridine;

3-Chlorornethyl-9-methyl-l-oxo-2,9-dihydro-lH-2,4,9-triaza-fluoren-5-carbonitrile was prepared using chloroacetonitrile; 6-Chloromethyl-9-methyl-8-oxo-8,9-dihydrό-7H-l,5,7,9-tetraaza-fluorene-4-carbonitrile was prepared using chloroacetonitrile; ό-Chloromethyl^^-dimethyl-S-oxo-S^-dihydro-TH-l^J^-tetraaza-fluorene^- carboxylic acid ethyl ester was prepared using chloroacetonitrile;

Conversion of one compound of formula (TV") into another compound of formula

Reference Example 3C.

3-Chloromethyl-6-nitro-2,9-dihvdro-2,4,9-triaza-fluoren-l-one

To a solution of 3-chloromethyl-2,9-dihydro-2,4,9-triaza-fluoren-l-one (502mg) in concentrated sulphuric acid (2ml) at 0⁰C was added a solution of sodium nitrate

(206.4mg, l.lequiv.) in concentrated sulphuric acid (2ml) and water (ldrop) dropwise.

Stirred at 0⁰C for 2 hours. Carefully added ice and the precipitate obtained was collected by filtration, washed with water and dried to give the resulting compound as a yellow solid (560mg).

3-Chloromethyl-6,8-dinitro-2,9-diliydro-2,4,9-triaza-fluoren-l-one was prepared in an analogous manner from 3-chloromethyl-2,9-dihydro-2,4,9-triaza-fluoren-l-one using 2.1 equivalents of sodium nitrate.

Reference Example 3D

3-Dimethylaminomethyl-2.9-dihvdro-2,4,9-triaza-fluoren-l-one 3-Chloromethyl-2,9-diliydro-2,4,9-triaza-fluoren-l-one (296mg), dimethylamine (2M solution in methanol, 1.5ml, 2.4equiv.) and. sodium carbonate (187mg, 1.4equiv.) were refluxed in ethanol for 1.5 hours. The reaction mixture was cooled to room temperature, added water and extracted into ethyl acetate. The organic layer was dried (sodium sulphate) and the solvent removed in vacuo. The residue was triturated with diethyl ether to give the title compound as a pink solid (141mg).

The following compounds of formula (IV) were prepared in an analogous manner from the compound of formula (IV) and the appropriate nucleophile.

3-Morpholin-4-yhnethyl-6-nitro-2,9-dihydro-2,4,9-triaza-fluoren-l-one was prepared from 3-chloromethyl-6-nitro-2,9-dihydro-2,4,9-triaza-iluoren-l-one and morpholine;

3-(4-Methyl-piperazin-l -ylmethyl)-6-nitro-2₅9-dihydro-2,4,9-triaza-fluoren- 1 -one was prepared from 3-chloromethyl-6-nitro-2,9-dihydro-2,4,9-triaza-fluoren- 1 -one and 1 - methylpiperazine;

3-Dimethylaminomethyl-6-nitro-2,9-dihydro-2,4,9-triaza-fluoren-l-one was prepared from 3-chloromethyl-6-nitro-2,9-dihydro-2,4,9-triaza-fluoren-l-one and dimethylarnine;

3-Morpholin-4-yhnethyl-6,8-dinitro-2,9-dihydro-2,4,9-triaza-fluoren-l-one was prepared from S-cUoromemyl-β^-dinitro^^-dihydro^^^-triaza-fluoren-l-one and morpholine.

3-Azidomemyl-9-methyl-l-oxo-2,9-dihydro-lH-2,4,9-triaza-fluoren-5-carbonitrile was prepared from 3-chloromethyl-9-methyl-l-oxo-2,9-dihydro-lH-2,4,9-triaza-fluoren-5- carbonitrile and sodium azide using N,N-dimethylformamide as solvent;

3 -Dimethylaminomethyl-9-methyl- 1 -oxo-2, 9-dihydro- 1 H-2,4,9-triaza-fiuoren-5- carbonitrile was prepared from 3-chloromethyl-9-methyl-l-oxo-2,9-dihydro-lH-2,4,9- triaza-fluoren-5-carbonitrile and dimethylamine;

3-Morpholm-4-yhnethyl-9-methyl-l-oxo-2,9-dihydro-lH-2,4,9-triaza-fluoren-5- carbomtrile was prepared from 3-chloromethyl-9-methyl-l-oxo-2,9-dihydro-lH-2,4,9- triaza-fluoren-5-carbonitrile and morpholine; 9-Memyl-6-morpholin-4-yhnethyl-8-oxo-8,9-dihydro-7H-l,5,7₅9-tetraaza-fluorene-4- carbomtrile was prepared from 6-chloromethyl-9-methyl-8-oxo-8,9-dihydro-7H-l, 5,7,9- tetraaza-fiuorene-4-carbonitrile and morpholine;

2,9-Dimethyl-6-morpholin-4-yhnethyl-8-oxo-8,9-dihydro-7H-l,5,7,9-tetraaza-fluorene-4- carboxylic acid ethyl ester was prepared from 6-chloromethyl-2,9-dimethyl-8-oxo-8,9- dihydro-7H-l,5,7,9-tetraaza-fluorene-4-carboxylic acid ethyl ester and morpholine; Reference Example 3E g-Methyl-l-oxo-Σ^-dihvdro-lH-Σ^.P-triaza-fluorene-S-caTboxylic acid A suspension of 9-methyl-l-oxo-2,9-dihydro-lH-2,4,9-triaza-fluorene-5-carbonitrile (800mg) in 30% potassium hydroxide (20ml) was heated to reflux for 8 hours. The reaction mixture was then cooled to room temperature, acidified with diluted hydrochloric acid and stirred for 20 min. The resulting precipitate was collected by filtration, washed with water, ethanol and then diethyl ether, air-dried to give the title product as a solid (690mg).

l-Oxo-2,9-dihydro-lH-2,4,9-triaza-fluorene-5-carboxylic acid was prepared in an analogous manner.

Reference Example 3F

1 -Oxo-2, 9-dihvdro- 1 H-2 A9-triaza-fluorene-5-carboxylic acid dimethylamide A suspension of l-oxo^jθ-dihydro-lH^^^-triaza-fluorene-S-carboxyhc acid (192mg) in DMF (4ml) was treated with 1,1 '-carbonyldiimidazole (271mg) and the mixture heated to 100⁰C for 24 hours, subsequently cooled to room temperature before the addition of dimethylamine (2.0M solution in tetrahydrofuran, 1.47ml). Stirred at room temperature overnight. The reaction mixture was diluted with dichloromethane, washed with brine, organic layer dried (magnesium sulphate), filtered and volatiles removed in vacuo. Trituration with ethyl ether afforded the title compound as a cream solid (1 lOmg).

The following compounds of formula (IV) were prepared in an analogous manner from the appropriate compound of formula (IV) and the appropriate amine.

9-Methyl-5-(4-methyl-piperazine-l-carbonyl)-2,9-dihydro-2,4,9-triaza-fluoren-l-one was prepared from 9-methyl-l-oxo-2,9-dihydro-lH-2,4,9-triaza-fluorene-5-carboxylic acid and 1-methylpiperazine;

9-Methyl-5-(moφholine-4-carbonyl)-2,9-dihydro-2,4,9-triaza-fluoren- 1 -one was prepared from 9-methyl-l-oxo-2,9-dihydro-lH-2,4,9-triaza-fluorene-5-carboxylic acid and morpholine. Reference Example 3 G

9-Methyl-6-oxy-2,9-dihvdro-2.4,6,9-tetraaza-£luoren-l-one To a suspension of 9-methyl-2,9-dihydro-2,4,6,9-tetraaza-fluoren-l-one (6.4Og) in chloroform (50OmL) at 0⁰C was added 3-chloroperbenzoic acid (16.6g). After stirring over the weekend, the reaction mixture was filtered to yield crude product. This was triturated with ethyl acetate to yield the desired N-oxide (6.9Ig).

Reference Example 4: Preparation of Compounds of General Formula (HT) Reference Example 4A

1 -F2-C3.4-Difluoro-phenylVethyli-piperazhie)

To a solution of 3,4-difluorophenylacetic.acid (24.8g) in dry tetrahydrofuran (15OmL) was added borane dimethylsulphide complex (21.6mL) at 0⁰C. After stirring overnight, the reaction was quenched with dilute hydrochloric acid, extracted into dichloromethane, dried (MgSO₄) and the solvent removed in vacuo to yield 2-(3,4-difluoro-phenyl)-ethanol as an oil which slowly crystallised (21.7g)

To a cold solution of 2-(3,4-difluoro-phenyl)-ethanol (21.7g) in dry dichloromethane (15OmL) was added p-toluenesulfonyl chloride (28.8g) and triethylamine (23.OmL). The reaction mixture was stirred overnight, diluted with dichloromethane, washed with water, dried (MgSO₄) and the solvent removed in vacuo to yield toluene-4-sulfonic acid 2-(3,4- difluoro-phenyl)-ethyl ester as a gum (41.1 g)

A mixture of toluene-4-sulfonic acid 2-(3,4-difluoro-phenyl)-ethyl ester (41.05g),,N- BOC-piperazine (24.5g) and potassium carbonate (18.Ig) was heated to reflux hi aoetonitrile (25OmL). After 16 hours at reflux the reaction mixture was reduced in vacuo, dissolved in dichloromethane and washed with water, dried (MgSO₄) and the solvent removed in vacuo to yield an oil which was purified using flash chromatography to yield 4-[2-(3,4-difluoro-phenyl)-ethyl]-piperazine-l-carboxylic acid tert-butyl ester (33.3g) A mixture of 4-[2-(3,4-difluoro-phenyl)-ethyl]-piperazine-l-carboxylic acid tert-butyl ester (10.26g) and trifluoroacetic acid (25mL) hi dichloromethane (10OmL) was stirred at room temperature overnight. The reaction mixture was then basifϊed carefully with potassium carbonate, extracted into dichloromethane, dried (MgSO₄) and the solvent removed in vacuo to yield the title compound as an oil (6.79g)

Reference Example 4B 4-Piperazin-l -ylmethyl-quinoline

A mixture of 4-quinolinecarboxaldehyde (578mg), 1-BOC-ρiperazine (685mg) and acetic acid (210μL) was stirred in 1,2-dichloroethane (1OmL) at room temperature. To this was added sodium triacetoxyborohydride (1.0Ig). After stirring overnight, the reaction mixture was washed with potassium carbonate solution, dried (MgSO₄) and the solvent removed in vacuo to yield 4-quinolin-4-yhnethyl-piperazine-l-carboxylic acid tert-butyl ester as an orange oil (1.73g). Treatment with trifluoroacetic acid in dichloromethane yielded the desired title compound.

In a similar manner, 2-piperazm-l-ylmethyl-quinoline was prepared from 2- quinolinecarboxaldehyde.

Reference Example 5: Preparation of compounds of General Formula (ID

Reference example 5A 1 -Chloro-9H-2.4.9-triaza-fluorene A mixture of 2,9-dihydro-2,4,9-triaza-fluoren-l-one (0.78g), triethylamine hydrochloride (0.46g) and phosphorous oxychloride (2OmL) was heated to reflux for 18 hours. The reaction mixture was then poured onto ice/water and the precipitate collected by filtration and washed with water to yield the desired title compound as a brown solid (0.7Og)

The following compounds of formula (II) were prepared in an analogous manner from the appropriate compound of formula (IV)

l-Chloro-9H-2,4,9-triaza-fluorene-6-carboxylic acid methyl ester; l-Chloro-9H-2,4,9-triaza-fluorene-5-carbonitrile; 1 ,5-Dichloro-9H-2,4,9-triaza-fluorene;^" 1 -Chloro-5-nitro-9H-2,4,9-triaza-fluorene; l-Chloro-9-methyl-5-nitro-2,4,9-triaza-fluorene; l-Chloro-5-fluoro-9-methyl-2,4,9-triaza-fluorene; l-Chloro-3-methyl-9H-2,4,9-triaza-fluorene; l-Chloro-3-pyridin-2-yl-9H-2,4,9-triaza-fluorene; (1 -Chloro-9H-2,4,9-triaza-fluoren-3-ylniethyl)-draiethyl-ainine;

1 -Chloro-3-morpholin-4-ylmethyl-6-nitro-9H-2,4,9-triaza-fluorene;

1 -Chloro-3-(4-methyl-piperazin- 1 -ylmethyl)-6-nitro-9H-2,4,9-triaza-fluorene;

(l-CUoro-6-nitro-9H-2,4,9-triaza-fluoren-3-ylmethyl)-dimethyl-arnine; l-Chloro-3-morpholin-4-ylmethyl-6,8-dinitro-9H-2,4,9-triaza-fluorene; l-Chloro-9H-2,4,9-triaza-fluorene-5-carboxylic acid dimethylamide;

(l-Chloro-9-methyl-9H-2,4,9-triaza-fluoren-5-yl)-(4-methyl-piperazin-l-yl)-methanone;

(l-Chloro-9-methyl-9H-2,4,9-triaza-fluoren-5-yl)-moφholm-4-yl-methanone;

3-Azidomethyl- 1 -chloro-9-methyl-9H-2,4,9-triaza-fluorene-5-carbonitrile; l-Chloro-6-methoxy-9H-2,4,9-triaza-fluorene; 1 -Chloro-6-trifluoromethoxy-9H-2,4,9-triaza-fluorene; l-Chloro-7-methoxy-9H-2,4,9-triaza-fluorene;

1 -Chloro-5-methyl-9H-2,4,9-triaza-fluorene; l-CMoro-3-morpholin-4-ylmethyl 9-methyl-9H-2,4,9-triaza-fluorene-5-carbonitrile; l-CMoro-3-dimethylaminomethyl-9-methyl-9H-2,4,9-triaza-fluorene-5-carbonitrile; 8-Chloro-9-methyl-6-morpholin-4-ylmethyl-9H-l ,5,7,9-tetraaza-fluorene-4-carbonitrile ;

8-Chloro-9-methyl-9H-l,5,7,9-tetraaza-fluorene-4-carbonitrile;

8-Chloro-2,9-dimethyl-6-morpholin-4-ylmethyl-9H-l,5,7,9-tetraaza-fluorene-4- carboxylic acid ethyl ester;

8-Chloro-2,9-dimethyl-9H-l,5,7,9-tetraaza-fluorene-4-carbonitrile (note primary amide converted to nitrile in this step); l,5-Dichloro-9-methyl-9H-2,4,6,9-tetraaza-fluorene (note N-oxide converted into chlorcb pyridine in this step);

1 -Chloro-9-methyl-9H-2,4,6,9-tetraaza-fluorene;

(9-Benzyl- 1 -cMoro-9H-2,4,6,94etraaza-fluoren-5-yl)-dimethyl-arnine; l-Chloro-9H-2,4,5,9-tetraaza-fluorene; Conversion of one compound of General Formula OD into another compound of Formula (ID

Reference example 5B l-Chloro-6-nitro-9H-2.4,9-triaza-fluorene Sodium nitrate (0.26g) was dissolved in concentrated sulphuric acid (3mL) with a few drops of water. This solution was added dropwise to a stirring solution of l-chloro-9H- 2,4,9-triaza-fluorene (0.57g) in concentrated sulphuric acid (2OmL) at Q⁰C. The reaction was allowed to warm slowly to room temperature and stirred overnight. The reaction mixture was poured onto ice and the precipitated solid was collected by filtration to yield the desired title compound (0.68g)

In a similar manner l-chloro-6-methoxy-5-nitro-9H-2,4,9-triaza-fluorene was prepared from l-chloro-6- methoxy-9H-2,4,9-triaza-fluorene; l-Chloro-7-methoxy-8-nitro-9H-2,4,9-triaza-fluorene was prepared from l-chloro-7- methoxy-9H-2,4,9-triaza-fluorene.

Reference example 5C

6-Bromo-l-chloro-9-methyl-9H-2,4,9-triaza-fluorene l-Chloro-9-methyl-9H-2,4,9-triaza-fluorene (1 lOmg) was dissolved in acetic acid (2mL) at 0⁰C. To this was added bromine (1.1 equivalents), and the reaction mixture was warmed to room temperature. After 2 hours a solid had appeared. This was collected by filtration and washed with acetic acid to yield the title compound as its acetic acid salt

(200mg)

Reference example 5D

9-Benzyl-l-chloro-6-nitro-9H-2,4,9-triaza-fluorene

To a solution of l-chloro-6-nitro-9H-2,4,9-triaza-fluorene (O.lg) in dimethylformamide

(4mL) was added sodium hydride (0.023g) . After stirring for 15 minutes, benzyl bromide (54μL) was added. The reaction mixture was stirred at room temperature overnight, and then quenched with water, extracted into ethyl acetate, dried (MgSO₄) and the solvent removed in vacuo. The crude residue was purified using flash chromatography to yield the title compound (0.12g).

The following compounds of formula (II) were prepared in an analogous fashion from the appropriate alkylating agent.

(l-Chloro-6-nitro-2,4,9-triaza-fluorene-9-yl) acetic acid ethyl ester was prepared using ethyl bromoacetate; l-Chloro-9-methyl-9H-2,4,9-triaza-fluorene was prepared using methyl iodide; l-Chloro-9-methyl-6-nitro-9H-2,4,9-triaza-fluorene was prepared using methyl iodide; (l-Chloro-6-nitro-2,4,9-triaza-fluoren-9-yl)-acetonitrile was prepared from bromoacetonitrile.

Reference example 5E

1 -CMoro-9-memyl-9H-2 A9-1riaza-fluorene-6-sulphonyl chloride l-Chloro-9-methyl-9H-2,4,9-triaza-fluorene (183mg) was added portion-wise to chlorosulphonic acid (2mL) at O⁰C. After 2 hours the mixture was heated to 100⁰C and maintained at this temperature for 1 hour. The reaction mixture was then cooled, poured onto ice/water carefully and the resulting precipitate was collected by filtration to yield the desired title compound (221mg).

The following compounds of formula (II) were prepared in an analogous manner. l-chloro-9H-2,4,9-triaza-fluorene-6-sulphonyl chloride was prepared from l-chloro-9H-

2,4,9-triaza-fluorene; l-Chloro-6-methoxy-9H-2,4,9-triaza-fluorene-5-sulphonyl-chloride was prepared from 1- chloro-6-methoxy-9H-2,4,9-triaza-fluorene;

Reference example 5F l-Chloro-9-methyl-9H-2,4,9-triaza-fluorene-6-sulphonic acid dimethylamide To l-chloro-9-methyl-9H-2,4,9-triaza-fluorene-6-sulphonyl chloride (113mg) in dichloromethane was added dimethylamine hydrochloride (250mg) and triethylamine (0.6mL). The reaction mixture was stirred for 1 hour and then quenched with water, extracted into dichloromethane, dried (MgSO₄) and the solvent removed in vacuo to yield the desired title compound.

The following compounds of formula (II) were prepared in an analogous fashion from the appropriate amine and sulphonyl chloride, l-Chloro-9-methyl-9H-2,4,9-triaza-fluorene-6-sulphonic acid methylamide was prepared from methylamine; l-Chloro-9H-2,4,9-triaza-fluorene-6-sulphonic acid benzylamide was prepared from benzylamine; 1 -Chloro-9H-2,4,9-triaza-fluorene-6-sulphonic acid phenylamide was prepared from aniline; l-Chloro-9H-2,4,9-triaza-fluorene-6-sulphonic acid amide was prepared from ammonia; l-Chloro-6-(morpholine-4-sulphonyl)-9H-2,4,9-triaza-fluorene was prepared from morpholine; 1 -Chloro-6-(pyrrolidine- 1 -sulphonyl)-9H-2,4,9-triaza-fluorene was prepared from pyrrolidine; l-Chloro-6-methoxy-9H-2,4,9-triaza-fluorene-5-sulphonic acid amide was prepared from

1 -chloro-6-methoxy-9H-2,4,9-triaza-fluorene-5-sulphonyl-chloride.

Reference Example 5G l-Chloro-9H-2.4.9-triaza-fluoren-6-ol

To a cold suspension of l-chloro-6-methoxy-9H-2,4,9-triaza-fluorene (106mg) in dichloromethane (2mL) was added a EVI solution of boron tribromide in dichloromethane (2mL). After stirring overnight, the reaction mixture was quenched with water, extracted into ethyl acetate, dried (MgSO₄) and the solvent removed in vacuo to yield a yellow solid which was further purified using column chromatography (46mg)

Example 1: Preparation of Compounds of General Formula (D l-l4-r2-(3,4-Difluoro-phenylVethyll-piperazin-l-yll-6-nitro-9H-2,4,9-triaza-fluorene A mixture of l-chloro-6-nitro-9H-2,4,9-triaza-fluorene (680mg), l-[2-(3,4-difluoro- phenyl)-ethyl]-piperazine (680mg) and triethylamine (0.42mL) was heated in dimethylformamide (7mL) at 8O⁰C overnight. The reaction mixture was cooled, poured onto ice/water and the precipitated solid collected by filtration, and triturated from hot ethyl acetate to yield the desired title compound (0.88g)

The following compounds of formula (I) were prepared in an analogous manner from the appropriate compounds of formula (II) and (III)

9-Methyl-l-(4-phenethyl-piperazin-l-yl)-9H-2,4,9-triaza-fluorene ;

6-Bromo- 1 - {4-[2-(3,4-difluoro-phenyl)-ethyl]-piperazin- 1 -yl} -9-methyl-9H-2,4,9-triaza- fluorene; 1 - {4-[2-(3 ,4-Difluoro-phenyl)-ethyl]-piperazin- 1 -yl} -9H-2,4,9-triaza-fluorene-6- carboxylic acid methyl ester; l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazm-l-yl}-9H-2,4,9-triaza-fluorene-5- carbonitrile; l-{4-[2-(3,4-Difluoro-phenyl)-etiiyl]-piperazni-l-yl}-9-methyl-9H-2,4,9-triaza-fluorene- 6-sulfonic acid dimethylamide; l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9-methyl-9H-2,4,9-triaza-fluorene-

6-sulfonic acid methylamide;

5-Chloro- 1 - {4-[2-(3 ,4-difluoro-phenyl)-ethyl]-piperazin- 1 -yl} -9H-2,4,9-triaza-fluorene;

9-Benzyl-l-{4-[2-(3,4-difluoro-phenyl)-ethyl]-piperazin-l-yl}-6-nitro-9H-2,4,9-triaza- fluorene;

1 - {4-[2-(3 ,4-Difluoro-phenyl)-ethyl]-piperazin-l -yl} -5-nitro-9H-2,4,9-triaza-fluorene;

1. {4-[2-(3 ,4-Difluoro-phenyl)-ethyl]-piperazin- 1 -yl} -9-methyl-5-nitro-9H-2,4,9-triaza- fluorene; l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-5-fluoro-9-methyl-9H-2,4,9-triaza- fluorene;

1 - {4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin- 1 -yl} -9H-2,4,9-triaza-fluorene-6-sulfonic acid benzylamide;

1 - {4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin- 1 -yl} -9H-2,4,9-triaza-fluorene-6-sulfonic acid phenylamide; l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9H-2,4,9-triaza-fluorene-6-sulfonic acid amide; l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-6-(morpholine-4-sulfonyl)-9H-

2,4,9-triaza-fluorene; l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-6-(pyrrolidine-l-sulfonyl)-9H-

2,4,9-triaza-fluorene; l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-3-methyl-9H-2,4,9-triaza-fluorene;

1 - {4-[2-(3 ,4-Difluoro-phenyl)-ethyl]-piperazin-l -yl} -3-pyridin-2-yl-9H-2,4,9-triaza- fluorene;

(l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l_^yl}-9H-2,4,9-triaza-fluoren-3- ylmethyl)-dimethyl-amine; l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-3-morpholin-4-ylmethyl-6-nitro-

9H-2,4,9-triaza-fluorene; l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-3-(4-methyl-piperazin-l-ylmethyl)-

6-nitro-9H-2,4,9-triaza-fluorene;

(l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-6-nitro-9H-2,4,9-triaza-fluoren-3- ylmethyl)-dimethyl-amine; l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-3-morpliolm-4-ylmethyl-6,8- dinitro-9H-2,4,9-triaza-fluorene; l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9H-2,4,9-triaza-fluorene-5- carboxylic acid diethylamide; (l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9-methyl-9H-2,4,9-triaza-fluoren-

5-yl)-(4-methyl-piperazin-l-yl)-methanone;

(l-{4-[2-(3,4-Difluoro-phenyl)-eΛyl]-piρerazin-l-yl}-9-methyl-9H-2,4,9-triaza-fluoren-

5-yl)-morpholin-4-yl-methanone;

1 - {4-[2-(3 ,4-Difluoro-phenyl)-ethyl]-piperazin- 1 -yl} -9-methyl-6-nitro-9H-2,4,9-triaza- fluorene;

(l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-6-nitro-2,4,9-triaza-fluoren-9-yl)- acetic acid ethyl ester;

3-Azidomethyl-l-{4-[2-(3,4-difluoro-phenyl)-ethyl]-piperazin-l-yl}-9-methyl-9H-2,4,9- triaza-fluorene-5-carbonitrile; l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-6-methoxy-9H-2,4,9-triaza- fluorene; l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-6-trifluoromethoxy-9H-2,4,9-triaza- fluorene;

1 - {4-[2-(3 ,4-Difluoro-phenyl)-ethyl]-piperazin- 1 -yl} -5-methyl-9H-2,4,9-triaza-fluorene;

3-Diethylaminomethyl-l-{4-[2-(3,4-difluoro-phenyl)-ethyl]-piperazin-l-yl}-9-metliyl- 9H-2,4,9-triaza-fluorene-5-carbonitrile;

1 - {4-[2-(3 ,4-Difluoro-phenyl)-ethyl]-piperazin-l -yl } -9-me1hyl-3-morpholm-4-ylmethyl-

9H-2,4,9-triaza-fluorene-5-carbonitrile;

1 - {4-[2-(3 ,4-Difluoro-phenyl)-ethyl]-piperazin-l -yl} -6-methoxy-5-nitro-9H-2,4,9-triaza- fluorene; l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-7-meihoxy-9H-2,4,9-triaza- fluorene; l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9H-2,4,9-triaza-fluoren-6-ol; l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-6-methoxy-9H-2,4,9-triaza- fluorene-5-sulfonic acid amide; 8-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9-methyl-6-morpholin-4-ylmethyl-

9H-l,5,7,9-tetraaza-fluorene-4-carbonitrile;

8- {4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l -yl} -9-methyl-9H-l ,5,7,9-tetraaza- fluorene-4-carbonitrile;

(l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-6-nitro-2,4,9-triaza-fluoren-9-yl)- acetonitrile;

8-{4-[2-(3,4-Difluoro-phenyl)rethyl]-piperazin-l-yl}-2,9-dimethyl-6-morpholin-4- ylmethyl-9H-l,5,7,9-tetraaza-fluorene-4-carboxylic acid ethyl ester;

8-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-2,9-dimethyl-9H-l,5,7,9-tetraaza- fluorene-4-carboxylic acid amide ; 1 - {4-[2-(3 ,4-Difluoro-phenyl)-ethyl]-piperazin-l -yl} -7-methoxy-8-nitro-9H-2,4,9-triaza- fluorene;

5-Chloro-l-{4-[2-(3,4-difluoro-phenyl)-ethyl]-piperazin-l-yl}-9-methyl-9H-2,4,6,9- tetraaza-fluorene; l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9-methyl-9H-2,4,6,9-tetraaza- fluorene; (9-Benzyl-l-{4-[2-(3,4-difluoro-phenyl)-ethyl]-piperazin-l-yl}-9H-2,4,6,9-tetraaza- fluoren-5-yl)-dimethyl-amine; l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9H-2,4,5,9-tetraaza-fluorene; 6-Nitro-l-(4-quinolin-4-ylmethyl-piperazin-l-yl)-9H-2,4,9-triaza-fluorene; 6-Nitro- 1 -(4-quinolin-2-ylmethyl-piperazin-l -yl)-9H-2,4,9-triaza-fluorene.

Example 2: Conversion of one compound of General Formula (D into another compound of Formula (D

Example 2A l-l4-r2-r3.4-Difluoro-phenylVethyl1-piperazin-l-vU-9-methyl-9H-2.4,9-triaza-fluorene- 6-carboxylic acid methyl ester

To a solution of l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9H-2,4,9-triaza- fluorene-6-carboxylic acid methyl ester (lOOmg) in dimethylformamide (ImL) at 0°C was added sodium hydride (60% suspension in mineral oil, 6.6mg). After stirring for 40 minutes, methyl iodide (15μL) was added. After 5 hours, the reaction mixture was quenched with water, and the resulting precipitate collected by filtration to yield crude product which was purified using chromatography to yield the title compound (63mg)

The following compounds of formula (I) were prepared in an analogous manner from the appropriate alkylating agent;

l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9-methyl-9H-2,4,9-triaza-fluorene-

5-carbonitrile was prepared using methyl iodide; l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9-(2-moφholin-4-yl-2-oxo-ethyl)- 9H-2,4,9-triaza-fluorene-5-carbonitrile was prepared using 4-chloroacetyl-morpholine. 4-

Chloroacetyl-moφholine was prepared from chloroacetyl chloride and morpholine;

9-Cyanomethyl-l-{4-[2-(3,4-difluoro-phenyl)-ethyl]-piperazin-l-yl}-9H-2,4,9-triaza- fluorene-5-carbonitrile was prepared using bromoacetonitrile;

2-(5-Cyano- 1 - {4-[2-(3 ,4-difluoro-phenyl)-ethyl]-piperazin-l -yl} -2,4,9-triaza-fiuoren-9- yl)-N,N-dimethyl-acetamide was prepared using 2-chloro-N,N-dimethylacetamide; l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piρerazin-l-yl}-9-pyridin-4-ylmethyl-9H-2,4,9- triaza-fluorene-5-carbonitrile was prepared using 4-picolyl chloride;

9-Benzyl-l-{4-[2-(3,4-difluoro-phenyl)-ethyl]-piperazin-l-yl}-5-nitro-9H-2,4,9-triaza- fluorene was prepared using benzyl bromide; 9-(4-Chloro-benzyl)- 1 - {4-[2-(3 ,4-difluoro-phenyl)-ethyl]-piperazin- 1 -yl} -5-nitro-9H-

2,4,9-triaza-fluorene was prepared using 4-chlorobenzyl bromide;

1 - {4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l -yl}-9-(4-methoxy-benzyl)-5-nitro-9H-

2,4,9-triaza-fluorene was prepared using 4-methoxybenzyl chloride;

4-(l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-5-nitro-2,4,9-triaza-fluoren-9- ylmethyl)-benzoic acid methyl ester was prepared using methyl 4-(bromomethyl) benzoate;

1 - {4-[2-(3 ,4-Difluoro-phenyl)-ethyl]-piperazin- 1 -yl} -9-(3-methoxy-benzyl)-5-nitro-9H-

2,4,9-triaza-fluorene; l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9-ethyl-5-nitro-9H-2,4,9-triaza- fluorene was prepared using ethyl bromide;

1 - {4-[2-(3 ,4-Difluoro-phenyl)-ethyl]-piperazin-l -yl} -9-isopropyl-5-nirro-9H-2_s4,9-triaza- fluorene was prepared using 2-iodopropane;

1 - {4-[2-(3,4-Dffluoro-phenyl)-e%l]-piperazin- 1 -yl} -9-isobutyl-5-nitro-9H-2,4,9-triaza- fluorene was prepared using l-iodo-2-methylpropane; l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-5-nitro-9-phenethyl-9H-2,4,9- triaza-fluorene was prepared using (2-bromoethyl)benzene;

1 - {4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l -yl} -5-nitro-9-pyridin-3-yhnethyl-9H-

2,4,9-triaza-fluorene was prepared using 3-picolyl chloride;

1 - {4-[2-(3 ,4-Difluoro-phenyl)-ethyl]-piperazin-l -yl} -5-nitro-9-pyridin-4-yhnethyl-9H- 2,4,9-triaza-fluorene was prepared using 4-picolyl chloride;

9-(2,6-Dichloro-benzyl)- 1 - {4-[2-(3,4-difluoro-phenyl)-ethyl]-piperazin- 1 -yl} -5-nitro-9H-

2,4,9-triaza-fluorene was prepared using 2,6-dichlorobenzyl bromide; l-{4-[2-(3,4-Difluoro-phenyl)-e1iiyl]-piperazin-l-yl}-9-pyridin-4-yhnethyl-9H-2,4,9- triaza-fluorene-5-carboxylic acid amide was prepared using 4-picolyl chloride; 1 - {4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l -yl} -θ-dimemylcarbamoylmethyl-ΘH- 2,4,9-triaza-fluorene-5-carboxylic acid amide was prepared using 2-chloro-N,N- dimethylacetamide;

(5-Carbamoyl-l-{4-[2-(3,4-difluoro-phenyl)-ethyl]-piperazin-l-yl}-2,4,9-triaza-fluoren- 9-yl)-acetic acid ethyl ester was prepared using ethyl bromoacetate;

Example 2B l-(4-[2-(3,4-Difluoro-phenyl)-ethyll-piperazin-l-vU-9H-2.4.9-triaza-fluorene-5- carboxylic acid amide A mixture of 1- {4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9H-2,4,9-triaza- fluorene-5-carbonitrile (500mg), sodium hydroxide solution (IM, 1.2mL) and 30% hydrogen peroxide solution (0.7mL) were stirred in methanol (3OmL) for 3 days.

Saturated sodium carbonate solution was added resulting in a precipitate, which was collected by filtration to yield crude product which was purified using flash chromatography to yield the title compound ( 143mg)

The following compounds of formula (I) were prepared in an analogous manner from the appropriate nitrile;

1 - {4-[2-(3 ,4-Difluoro-phenyl)-ethyl]-piperazin- 1 -yl} -9-methyl-9H-2,4,9-triaza-fluorene- 5-carboxylic acid amide; l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9-methyl-3-morpholin-4-ylmethyl-

9H-2,4,9-triaza-fluorene-5-carboxylic acid amide;

3 -Diethylaminomethyl- 1 - {4-[2-(3 ,4-difluoro-phenyl)-ethyl]-piperazin- 1 -yl } -9-methyl-

9H-2,4,9-triaza-fluorene-5-carboxylic acid amide; 8- {4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l -yl} -9-methyl-9H-i ,5,7,9-tetraaza- fluorene-4-carboxylic acid amide;.

8-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9-methyl-6-morpholin-4-ylmethyl-

9H-l,5,7,9-tetraaza-fluorene-4-carboxylic acid amide;

8-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-2,9-dimethyl-9H-l,5,7,9-tetraaza- fluorene-4-carboxylic acid amide; Example 2C fl-l4-r2-(3.4-Difluoro-phenylVethyll-piperazin-l-vU-9H-2.4.9-triaza-fluoren-6-ylV p yrrolidin- 1 - yl-methanone

A mixture of l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9H-2,4,9-triaza- fluorene-6-carboxylic acid methyl ester (88mg) and pyrrolidine was heated to 85⁰C for 16 hours. The resulting mixture was purified using flash chromatography to yield the desired title compound (46mg)

The following compounds of formula (I) were prepared in an analogous manner from the appropriate amine; l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9H-2,4,9-triaza-fluorene-6- carboxylic acid cyclohexylamide was prepared from cyclohexylamine; l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9H-2,4,9-triaza-fluorene-6- carboxylic acid (2-methoxy-ethyl)-amide was prepared from 2-methoxyethylamine; 8-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-2,9-dimethyl-6-morpholin-4- ylmethyl-9H-l,5,7,9-tetraaza-fluorene-4-carboxylic acid amide was prepared using ammonia in methanol in a sealed tube at 110⁰C;

Example 2D l-f4-r2-^3.4-Difluoro-phenylVethyll-piperazin-l-vU-9H-2.4.9-triaza-fluorene-5- carboxylic acid pyridin-2-ylamide Reference Procedure: Org Lett 2000 ppl 101-1104 A mixture of l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9H-2,4,9-triaza- fluorene-5-carboxylic acid amide (68mg) and 2-brornopyridine (1.1. equivalents) was stirred in 1,4-dioxane (ImL). To this was added caesium carbonate (78mg), tris(dibenzylideneacetone)dipalladium (1.5mg) and Xanthphos (1.5mg). The reaction mixture was heated to 100°C for 3 days. After cooling, the reaction mixture was extracted into dichloromethane, washed with water, dried (MgSO₄) and the solvent removed in vacuo to yield crude product which was purified using flash chromatography to yield the title compound (22mg). The following compounds of formula (I) were prepared in an analogous manner from the appropriate aryl halide; l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9H-2,4,9-triaza-fluorene-5- carboxylic acid pyridin-4-ylamide was prepared using 4-bromopyridine; l-{4-[2-(3,4-Difluoro-phenyl)-e1hyl]-pipera2in-l-yl}-9-methyl-9H-2,4,9-triaza-fluorene- 5-carboxylic acid (3-nitro-phenyl)-amide was prepared using 3-bromo-nitrobenzene;

Example 2E

1 - (4-r2-(3.4-Difluoro-phenylVemyli-piperazin-l -yl) -9H-2.4.9-triaza-fluorene-6- carboxylic acid, sodium salt

To l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9H-2,4,9-triaza-fluorene-6- carboxylic acid methyl ester (300mg) in ethanol (3mL) was added a solution of sodium hydroxide (54mg) in water (ImL). The reaction mixture was refluxed for 2 days, and then cooled. The reaction mixture was reduced in vacuo, and water was added. After standing a precipitate appeared which was collected by filtration to yield the title compound.

Example 2F l-{4-r2-G.4-Difluoro-phenylVethvn-ρiperazin-l-vU-9H-2.4.9-triaza-fluorene-5- carboxylic acid: hydrochloride To l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9H-2,4,9-triaza-fluorene-5- carbonitrile (220mg) in ethanol (4mL) was added a solution of potassium hydroxide (206mg) in water (1.5mL). The reaction mixture was refluxed for 2 days. After cooling, the reaction mixture was partitioned between water and dichloromethane. The aqueous phase was collected and neutralised with HCl (2M) yielding a precipitate which was collected by filtration. This solid was suspended in dichloromethane/acetone and HCl in ether (2M, 0.5mL) was added. After stirring for 30 minutes all the volatiles were removed in vacuo to yield the title compound.

Example 2G 1 - 14-[2-(3 ,4-Difluoro-phenylVethyll-piperazin- 1 -yl} -9H-2.4.9-triaza-fluoren-6-ylamine A solution of l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-6-nitro-9H-2,4,9- triaza-fluorene (3.22g) in dichloromethane/methanol (1:1, 10OmL) was stirred under a positive pressure of hydrogen over palladium on activated carbon (~0.5g) for 16 hours. The reaction mixture was filtered through celite and the filtrate reduced in vacuo to yield the desired title compound (2.84g)

The following compounds of formula (T) were prepared in an analogous manner from the appropriate nitro containing compound; l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9H-2,4,9-triaza-fluoren-5-ylamine; 1 - {4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l -yl} -6-methoxy-9H-2,4,9-triaza-fluoren- 5-ylamine;

Similar conditions were used to prepare 3-aminomethyl-l-{4-[2-(3,4-difluoro-phenyl)- ethyl]-piperazήi-l-yl}-9-methyl-9H-2,4,9-triaza-fluorene-5-carbonitrile by reduction of the azide group.

Example 2H

4-Chloro-N-d-f4-r2-(3,4-difluoro-phenylVethyl1-piperazin-l-vU-9H-2_<4,9-triaza- fluoren-6-ylVbenzamide

To a solution of l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9H-2,4,9-triaza- fluoren-6-ylamine (70mg) in pyridine (ImL) was added 4-chlorobenzoyl chloride (22μL).

The reaction mixture was heated to 5O⁰C overnight and then cooled. The mixture was diluted with ethyl acetate, washed with water, dried (MgSO₄) and the solvent removed in vacuo to yield crude product which was purified using flash chromatography to yield the title compound (45mg).

The following compounds of formula (I) were prepared in an analogous manner from the appropriate reagent;

N-(l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9H-2,4,9-triaza-fluoren-6-yl)- methanesulfonamide was prepared from methanesulfonyl chloride; N4-[2-(3 ,4-Difluoro-phenyl)-ethyl]-piperazin- 1 -yl} -9H-2,4,9-triaza-fluoren-6-yl)- acetamide was prepared from acetic anhydride in dichloromethane with triethylamine present;

N-(l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9H-2,4,9-triaza-fluoren-6-yl)- benzenesulfonamide was prepared from benzenesulfonyl chloride;

Cyclohexanecarboxylic acid (1 - {4-[2-(3,4-difluoro-phenyl)-ethyl]-piperazin-l -yl} -9H-

2,4,9-triaza-fluoren-6-yl)-amide was prepared from cyclohexanecarbonyl chloride;

N-(l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9H-2,4,9-triaza-fluoren-6-yl)- nicotinamide was prepared from nicotinoyl chloride hydrochloride; N-(l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9H-2,4,9-triaza-fluoren-6-yl)-4- methyl-benzamide was prepared from p-toluoyl chloride;

N-(l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazhi-l-yl}-9H-2,4,9-triaza-fluoren-6-yl)-2- phenoxy-acetamide was prepared from phenoxy acetyl chloride;

N-(l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9H-2,4,9-triaza-fluoren-6-yl)- succinamic acid methyl ester was prepared from 3-carbomethoxypropionyl chloride;

N-(l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9H-2,4,9-triaza-fluoren-5-yl)- acetamide was prepared from acetyl chloride;

N-(l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9H-2,4,9-triaza-fluoren-5-yl)- benzamide was prepared from benzoyl chloride; N-(l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9H-2,4,9-triaza-fluoren-6-yl)-2- phenyl-acetamide was prepared from phenylacetyl chloride;

N-( 1 - {4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin- 1 -yl} -9H-2,4,9-triaza-fluoren-6-yl)-C- phenyl-methanesulfonamide was prepared from alpha-toluene-sulphonyl chloride;

3-(l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9H-2,4,9-triaza-fluoren-6-yl)- 1,1 -dimethyl-urea was prepared from dimethylcarbamyl chloride;

N-(l-{4-[2-(3,4-Difluoro-ρhenyl)-ethyl]-piperazin-l-yl}-9H-2,4,9-triaza-fluoren-6-yl)-2- methoxy-acetamide was prepared from methoxyacetyl chloride;

N-(l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9H-2,4,9-triaza-fluoren-6-yl)-4- dimethylamino-benzamide was prepared from 4-dimethylaminobenzoyl chloride; N-(5-Cyano-l-{4-[2-(3,4-difluoro-phenyl)-ethyl]-ρiρerazin-l-yl}-9-methyl-9H-2,4,9- triaza-fluoren-3-ylmethyl)-acetamide was prepared using acetyl chloride in pyridine at 5O⁰C;

N-(5-Cyano-l-{4-[2-(3,4-difluoro-phenyl)-ethyl]-piperazin-l-yl}-9-methyl-9H-2,4,9- 1riaza-fluoren-3-ylmethyl)-methanesιιlfonarήide was prepared using methane sulphonyl chloride in pyridine at 100⁰C

Example 21

1 - (4-F2-C3.4-Difluoro-phenylVethvn-piperazin-l -yl) -9H-2 A9-triaza-fluorene-6- carboxylic acid methylamide l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9H-2,4,9-triaza-fluorene-6- carboxylic acid, sodium salt (84mg) was dissolved in water (5mL) and cone. HCl was added until precipitation occurred. Filtration yielded the free acid as a white solid.

The free acid (68mg) was suspended in dimethylformamide (2mL) and 1,1- carbonyldiimidazole (48mg) was added. The mixture was stirred at room temperature for

4 hours. Methylamine hydrochloride (20mg) and triethylamine (0.04mL) were then added. After stirring for a further 16 hours, water was added to the reaction mixture yielding a precipitate, which was purified using flash chromatography to yield the title compound (40mg)

The following compounds of formula (I) were prepared in an analogous manner from the appropriate amine; l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9H-2,4,9-triaza-fluorene-6- carboxylic acid amide was prepared using ammonium hydroxide; l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9H-2_J4,9-triaza-fluorene-6- carboxylic acid dimethylamide was prepared using dimethylamine;

Example 2J

9-Methyl-6-nitro-l-{4-r2-(4-nitro-phenyl)-ethyll-piperazin-l-yll-9H-2,4,9-triaza- fluorene 70% nitric acid (4mL) was added dropwise to a solution of acetic acid (2.4mL) and sulphuric acid (2.8mL) at -20⁰C. To this was added 9-Methyl-l-(4-phenethyl-piperazin-l- yl)-9H-2,4,9-triaza-fluorene (215mg) and the mixture was warmed slowly to room temperature. After 24 hours, the mixture was poured onto ice/water and basified (K₂CO₃) and the solid was collected by filtration. This material was dissolved in a mixture of 70% nitric acid (8mL) and cone, sulphuric acid (2mL) for 5 hours at room temperature. The mixture was poured onto ice water, basified (K₂CO₃) and extracted into dichloromethane, dried (MgSO₄) and the solvent removed hi vacuo to yield a yellow solid which was triturated with hot ethyl acetate to yield the desired title compound (78mg)

Example 2K. l-(4-r2-(3.4-Difluoro-phenylVethyll-piperazui-l-vπ-9-methyl-9H-2.4.9-triaza-fluorene- 5-carboxylic acid ethylamide Reference method: Tet. Lett. 40 (19991 pp2295-2298 To l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9-methyl-9H-2,4,9-triaza- fluorene-5-carboxylic acid amide (60mg) hi acetonitrile (2mL) was added acetaldehyde (17mg), triethylsilane (46mg) and trifluoroacetic acid (60mg). The reaction mixture was heated to reflux for 48 hours. The solvent was then removed in vacuo and the residue was dissolved in ethyl acetate, washed with sodium bicarbonate solution, dried (MgSO₄) and the solvent removed in vacuo to yield crude product. This was purified using flash chromatography to yield the title compound (43mg)

The following compounds of formula (I) were prepared hi an analogous manner using the appropriate primary amide and the appropriate aldehyde;

1 - {4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin- 1 -yl } -9-methyl-9H-2,4,9-triaza-fluorene- 5-carboxylic acid propylamide was prepared using propionaldehyde;

1 - {4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperaziα- 1 -yl} -9-methyl-9H-2,4,9-triaza-fluorene-

5-carboxylic acid (pyridin-2-ylmethyl)-amide was prepared using 2- pyridinecarboxaldehyde; l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazhi-l-yl}-9-methyl-9H-2,4,9-triaza-fluorene- 5-carboxylic acid 2,3-dimethoxy-benzylamide was prepared using 2,3- dimethoxybenzaldehyde; Example 2L l-(4-f2-(3.4-Difluoro-phenylVethyl1-piperazin-l-yll-5-r4J-dihv(ko-lH-imidazol-2-ylV 9-methyl-9H-2.4.9-triaza-fluorene A mixture of l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9-methyl-9H-2,4,9- triaza-fluorene-5-carbonitrile (75mg), phosphorous pentasulphide (~2mg) and ethylenediamine (ImL) was heated to 120⁰C for 4 hours. The reaction mixture was cooled, poured onto ice/water and the resulting precipitate was collected by filtration to yield the desired title compound (5 lmg).

In an analogous manner, l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9-methyl- 5-(l-methyl-4,5-dihydro-lH-imidazol-2-yl)-9H-2,4,9-triaza-fluorene was prepared using N-methylethylenediamine.

Example 2M.

1 - (4-r2-f 3.4-Difluoro-phenylV ethyll -piperaziή- 1 -yl 1 -5-( 1 H-imidazol-2- ylV 9-methyl-9H-

2,4,9-triaza-fluorene

A mixture of l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-5-(4,5-dihydro-lH- imidazol-2-yl)-9-methyl-9H-2,4,9-triaza-fluorene (36mg), Pd/C (36mg) and m-xylene (ImL) was heated to reflux for 2 days. The reaction mixture was filtered through celite and reduced in vacuo to yield a crude product which was purified using flash chromatography to yield the title compound (24mg).

l-{4-[2-(3,4-Difluoro-phenyl)-emyl]-piperazm-l-yl}-9-methyl-5-(l-methyl-lH-imidazol- 2-yl)-9H-2,4,9-triaza-fluorene was prepared in an analogous manner .

Example 2N

N-α-(4-r2-(3.4-Difluoro-phenylVethvn-ρiperazin-l-vU-9-methyl-9H-2.4.9-triaza- fluoren-5-ylmethylVacetamide A solution of l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9-methyl-9H-2,4,9- triaza-fluorene-5-carbonitrile (150mg) in tetrahydrofuran (3mL) was added to a cold solution (O⁰C) of lithium aluminium hydride 940mg) in tetrahydrofuran. After 2.5 hours the reaction mixture was quenched with water carefully. 15% sodium hydroxide solution was added and the reaction mixture was then diluted with dichloromethane and then filtered. The organic phase was collected, washed with 15% sodium hydroxide solution, dried (MgSO₄) and the solvent removed in vacuo to yield the corresponding primary amine (120mg).

To a solution of the primary amine (60mg) in dichloromethane (ImL) was added acetic anhydride (0.013mL) and triethylamine (0.019mL). The reaction mixture was stirred overnight, and then diluted with dichloromethane, washed with water, dried (MgSO₄) and the solvent removed in vacuo to yield crude product which was purified using flash chromatography to yield the desired title compound (14mg)

N-(I - {4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l -yl} -9-methyl-9H-2 ,4,9-triaza- fluoren-5-ylmethyl)-methanesulfonamide was prepared in an analogous manner using methane sulphonyl chloride.

Example 20 l-|4-r2-(3,4-Difluoro-phenylVethvn-piperazin-l-vU-9-methyl-5-(5-methyl- ri.2.41oxadia2ol-3-ylV9H-2,4.9-triaza-fluorene A mixture of l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9-methyl-9H-2,4,9- triaza-fluorene-5-carbonitrile (200mg), potassium carbonate (320mg) and hydroxylamine hydrochloride (160mg) in ethanol (5mL) was heated to reflux overnight. The reaction mixture was then cooled, reduced hi vacuo and triturated with water to yield l-{4-[2-(3,4- difluoro-phenyl)-ethyl]-piperazin-l-yl}-N-hydroxy-9-methyl-9H-2,4,9-triaza-fluorene-5- carboxamidine.

A mixture of l-{4-[2-(3,4-difluoro-phenyl)-ethyl]-piperazin-l-yl}-N-hydroxy-9-methyl- 9H-2,4,9-triaza-fluorene-5-carboxamidine (170mg) and acetyl chloride (0.039mL) in pyridine (3mL) was heated to 6O⁰C for 16 hours. To the cooled reaction mixture was added water and a precipitate was collected. This purified using flash chromatography to yield the desired title compound (47mg) 1 - {4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin- 1 -yl} -N-hydroxy-9-methyl-9H-2 ,4,9- triaza-fluorene-5-O-Acetoxy-carboxamidine was also isolated from the reaction. Treatment of this compound with 10% palladium on carbon in ethyl acetate under an atmosphere of hydrogen yielded the corresponding amidine, l-{4-[2-(3,4-Difluoro- phenyl)-ethyl]-piperazin- 1 -yl} -9-methyl-9H-2,4,9-triaza-fluorene-5-carboxamidine

The following compounds of formula (I) were prepared in an analogous manner using the appropriate acid chloride; l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-5-(5-isopropyl-[l,2,4]oxadiazol-3- yl)-9-methyl-9H-2,4,9-triaza-fluorene was prepared using isoburyryl chloride;

1 - {4-[2-(3 ,4-Difluoro-phenyl)-ethyl]-piperazin- 1 -yl} -5-(5-methoxymethyl-

[l,2,4]oxadiazol-3-yl)-9-methyl-9H-2,4,9-triaza-fluorene was prepared using methoxyacetyl chloride; l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9-methyl-5-(5-phenyl- [1 ,2,4]oxadiazol-3-yl)-9H-2,4,9-triaza-fluorene was prepared using benzoyl chloride;

Example 2P

Benzyl-f 1 - (4-F2-C3.4-difluoro-phenylVethyll-piperazin- 1 -vU -9H-2 A9-triaza-fluoren-6- yP-amine A suspension of l-{4-[2-(3,4-difluoro-phenyl)-ethyl]-piperazin-l-yl}-9H-2,4,9-triaza- fluoren-6-ylamine (70mg) and benzaldehyde (17.4μL) in methanol (2mL) was stirred for 30 minutes at room temperature. Sodium cyanoborohydride (16mg) and acetic acid (9.6μL) were then added and the reaction mixture was stirred for 3 hours. The reaction mixture was diluted with dichloromethane, washed with sodium carbonate solution, dried (MgSO₄) and the solvent removed in vacuo to yield crude product which was recrystallised from hexane / ethyl acetate to yield the title compound (36mg)

Example 20

1 -Cl - (4-r2-f 3 ,4-Difluoro-phenylVethyll-piperazin- 1 -yl> -9-methyl-9H-2 A9-triaza- fluoren-5-ylVethanone A solution of 3.0M methylmagnesium bromide in diethyl ether (0.1 ImL) was added to tetrahydrofuran (0.5mL). This was added to a solution of l-{4-[2-(3,4-Difluoro-phenyl)- ethyl]-piperazin- 1 -yl} -9-methyl-9H-2,4,9-triaza-fluorene-5-carbonitrile (50mg) in tetrahydrofuran (ImI). The mixture was heated to 60⁰C under nitrogen. After 2 hours the reaction mixture was carefully quenched with water, extracted into ethyl acetate, washed with water, dried (MgSO₄) and the solvent removed in vacuo to yield crude product. This was purified using flash chromatography to yield the title compound (9mg)

Example 2R d-^-r∑-rSΛ-Difluoro-phenylVethyll-piperazin-l-yll-g-methyl-gH-ΣΛ.e.g-tetraaza- fluoren-5-yD-ethyl-amine

Ethylamine was bubbled through n-butanol (3mL). Triethylamine (47μL) was added, followed by 5-Chloro-l-{4-[2-(3,4-difluoro-phenyl)-ethyl]-piperazin-l-yl}-9-methyl-9H-

2,4,6,9-tetraaza-fluorene (lOOmg). The reaction mixture was heated to 100⁰C overnight. The reaction mixture was diluted with chloroform, washed with brine, dried (MgSO₄) and the solvent removed in vacuo to yield a solid which was triturated with ether to yield the desired title compound.

The following compounds of formula (I) were prepared in an analogous manner using the appropriate amine.

(l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9-methyl-9H-2,4,6,9-tetraaza- fluoren-5-yl)-dimethyl-amine was prepared using dimethylamine;

(l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9-methyl-9H-2,4,6,9-tetraaza- fluoren-5-yl)-methyl-amine was prepared using methylamine; 1 - {4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l -yl} -9-methyl-5-morpholin-4-yl-9H-

2,4,6,9-tetraaza-fluorene was prepared using morpholine;

Benzyl-(l-{4-[2-(3,4-difluoro-phenyl)-ethyl]-piperazin-l-yl}-9-methyl-9H-2,4,6,9- tetraaza-fluoren-5-yl)-methyl-amine was prepared using benzylamine;

1 - {4-[2-(3 ,4-Difluoro-phenyl)-ethyl]-piperazin- 1 -yl} -9-methyl-5-(4-methyl-piperazin-l - yl)-9H-2,4,6,9-tetraaza-fluorene was prepared using N-methylpiperazine; 1 - {4-[2-(3 ,4-Difluoro-phenyl)-ethyl]-piperazin- 1 -yl} -9-methyl-5-piperidin-l -yl-9H-

2,4,6,9-tetraaza-fluorene was prepared using piperidine;

(l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9-methyl-9H-2,4,6,9-tetraaza- fluoren-5-yl)-pyridin-2-ylmethyl-amine was prepared using 2-aminornethylpyridine; (l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9-methyl-9H-2,4,6,9-tetraaza- fluoren-5-yl)-isopropyl-amine was prepared using isopropylamine; l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9-methyl-5-thiomoφholin-4-yl-9H-

2,4,6,9-tetraaza-fluorene was prepared using thiomorpholine; l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-5-(2,6-dimethyl-morpholin-4-yl)-9- methyl-9H-2,4,6,9-tetraaza-fluorene was prepared using cis-2,6-dimethylmorpholine;

Example 2S

N-a-{4-r2-(^"3.4-Difluoro-phenylVethyl]-piperazin-l-vU-9-rnethyl-9H-2.4.9-triaza- fluoren-5-ylmethyl)- acetamide The title compound was prepared from 5-Chloro-l-{4-[2-(3,4-difluoro-phenyl)-ethyl]- piperazin-l-yl}-9-methyl-9H-2,4,6,9-tetraaza-fluorene using methyl zinc chloride and tetrakis(triphenylphosphine)palladium(0) using a method described in the literature (Trecourt, F. et al, J. Org. Chem, 1998, 63, p2892).

Example 3: Testing of the compounds of formula (D as modulators of MRP

Materials and Methods

The COR.L23 human large cell lung cancer cell line and the MRP expressing multidrug resistant subline COR.L23/R were cultured in RPMI.1640 medium containing 10% foetal calf serum and 2mM glutamine at 37⁰C in 5% CO₂. Cells were passaged 1 in 10 for both the parental cell line and the MDR subline, after trypsinisation (0.25%, trypsin, 0.2g/L, EDTA)

1. Drug Accumulation Assay

COR.L23/R were seeded 48 hours prior to assay into 96 well opaque culture plates (Canberra Packard). The assay medium contained tritiated daunomycin (0.3μCi/mL), a cytotoxic anthracycline (NEN). Compounds of formula (I) were serially diluted in assay medium over a range of concentrations from 10-5000 nM. The cells were incubated at 37⁰C for 2 hours, before washing and determination of cell associated radioactivity. Results are expressed as an IC₅₀ for rritiated daunomycin accumulation where 100% accumulation is that observed in the presence of a standard inhibitor, 4-{4-[2-(3-nitro- phenyl)-ethyl]-piperazin-l-yl}-5,6,7,8-tetrahydro-l,3,4b-tria2afluorene-9-carbonitrile, at a concentration of 10 μM. Compounds of Formula (I) were active in the range 2OnM to 5μM. A selection of compounds is shown in Table 1 below.

Table 1

2. Potentiation of Doxorubicin Cytotoxicity

Selected compounds of formula (I) were examined for their ability to potentiate the cytotoxicity of doxorubicin for COR.L23/R cells. Cells were cultured for five days with a titration of doxorubicin (0.263nM-17.24μM) in the presence of compound at a range of concentrations from 16-200OnM. Cell viability was quantified by a fluorometric method using alamarBlue, a non-toxic metabolic indicator of viable cells that becomes fluorescent upon mitochondrial reduction (Nociari, M.M et al, J. Immunol Methods^ 1998, ppl57-167). The IC₅₀ (concentration required to reduce viable cells to 50% of the untreated controls) for doxorubicin alone, and for doxorubicin in the presence of each compound over the concentration range, were derived and used to calculate the EC₅₀. The EC₅₀ is the compound concentration effecting potentiation of doxorubicin cytotoxicity to 50% of the Rf value where

IC₅₀ for doxorubicin, COR.L23/R cells

Rf = IC₅₀ for doxorubicin, COR.L23 cells

Compounds of Formula (T) were active in the range 2OnM to 5μM. A selection of compounds is shown in Table 2 below.

Table 2

For a selection of compounds of Formula (T), the potentiation assay was also performed using a different cell line and also a variety of cytotoxics using the protocol described above. The results are shown in Table 3 Table 3

Example 4: Characterisation of the present compounds

The compounds prepared in the preceding Examples were characterised by proton N.M.R spectroscopy and mass spectroscopy. All proton N.M.R were performed at 300 or 400MHz. Characterisation by mass spectroscopy was performed using desorption chemical ionisation or electrospray ionisation. The results are set out in Table 4: Table 4

C27H28F2N6O | MH+ 491 | (CDC13/MeOD): 1.75-1.84 (2H, m), 1.85-1.95 (2H,

16

Example 5: Tablet composition Tablets, each weighing 0.15 g and containing 25 mg of a compound of the invention were manufactured as follows:

Composition for 10,000 tablets

Compound of the invention (250 g)

Lactose (800 g)

Corn starch (415g)

Talc powder (30 g)

Magnesium stearate (5 g)

The compound of the invention, lactose and half of the corn starch were mixed. The mixture was then forced through a sieve 0.5 mm mesh size. Corn starch (10 g) is suspended in warm water (90 ml). The resulting paste was used to granulate the powder.

The granulate was dried and broken up into small fragments on a sieve of 1.4 mm mesh size. The remaining quantity of starch, talc and magnesium was added, carefully mixed and processed into tablets.

Example 6: Injectable Formulation

Compound of the invention 200mg

Hydrochloric Acid Solution 0.1M or

Sodium Hydroxide Solution 0.1M q.s. to pH 4.0 to 7.0 Sterile water q.s. to 10 ml

The compound of the invention was dissolved in most of the water (35° 40° C) and the pH adjusted to between 4.0 and 7.0 with the hydrochloric acid or the sodium hydroxide as appropriate. The batch was then made up to volume with water and filtered through a sterile micropore filter into a sterile 10 ml amber glass vial (type 1) and sealed with sterile closures and overseals.

Example 7: Intramuscular Injection Compound of the invention 200 mg Benzyl Alcohol . 0.10 g

Glycofurol 75 1.45 g

Water for injection q.s to 3.00 ml

The compound of the invention was dissolved in the glycofurol. The benzyl alcohol was then added and dissolved, and water added to 3 ml. The mixture was then filtered through a sterile micropore filter and sealed in sterile 3 ml glass vials (type 1).

Example 8: Syrup Formulation

Compound of invention 250 mg Sorbitol Solution 1.50 g

Glycerol 2.00 g

Sodium benzoate 0.005 g

Flavour 0.0125 ml

Purified Water q.s. to 5.00 ml

The compound of the invention was dissolved in a mixture of the glycerol and most of the purified water. An aqueous solution of the sodium benzoate was then added to the solution, followed by addition of the sorbital solution and finally the flavour. The volume was made up with purified water and mixed well.

Claims

1. A compound which is a pyrrolopyrimidine of formula (I)

wherein

R¹ is selected from H, C₁-C₆ alkyl which is unsubstituted or substituted, (CH₂)_HAr¹,

(CH₂)_PNR⁴R⁵, halogen and (CH₂)_PX;

R² is (CH₂)_PAr¹;

R³ is selected from H, CrC₆ alkyl which is unsubstituted or substituted, (CH^pZ and (CH₂)_PAr¹;

P is an unsaturated 5, 6, or 7 membered carbocyclic or heterocyclic ring which is unsubstituted or substituted;

R⁴ and R⁵ which are the same or different are selected from H, Ci-C₆ alkyl which is unsubstituted or substituted, (CH₂)_nC₃-Cio cycloalkyl, (CH₂)_nAr', and (CH₂)_nOR⁶, or R⁴ and R⁵ together with the nitrogen atom to which they are attached, form a saturated five or six membered nitrogen containing heterocyclic ring which may contain one extra heteroatom selected from O, N and S and which is unsubstituted or substituted;

R⁶ is selected from H, Ci-C₆ alkyl which is unsubstituted or substituted, C₃-Ci₀ cycloalkyl, (CH₂)_nOCi-C₆alkyl which is unsubstituted or substituted, (CH^_rACH^_nAr¹, (CH₂)_nCO₂Ci-C₆alkyl which is unsubstituted or substituted and (CH₂)_nAr^!;

X is selected from CN, azide, (CH₂)_nNHSO₂R⁶ and (CH₂)_nNHCOR⁶;

Z is selected from CN, CO₂R⁶ and CONR⁴R⁵;

Ar¹ is the same or different when more than one is present within a given substituent group and is an unsaturated C₆-Ci₀ membered carbocylic group or an unsaturated 5-11 membered heterocycle, either of which is unsubstituted or substituted; p is an integer of 1 to 6; n is the same or different when more than one is present within a given substituent group and is 0 or an integer of 1 to 6; with the proviso that the pyrrolopyrimidine of formula (I) is other than l-(4-benzyl- piperazin- 1 -yl)-9H-2,4,9-triaza-fiuorene; or a pharmaceutically acceptable salt thereof.

2. A compound according to claim 1 wherein the pyrrolopyrimidine is of formula (Ia)

wherein R¹, R² and R³ are as defined in claim 1; and

Pl is an unsaturated C₆ carbocyclic group which is unsubstituted or substituted.

3. A compound according to claim 1 or 2 wherein the pyrrolopyrimidine is of formula (Ia')

(Ia¹)

wherein R¹, R² and R³ are as defined in claim 1 and R¹³ and R¹⁴ are selected from H, Ci- C₆ alkyl, OR⁶, halogen, nitro, CN, CO₂R⁶, (CH₂)_nCONR⁴R⁵, (CH₂)_nNHCOR⁶, NR⁴R⁵, SO₂NR⁴R⁵, (CH₂)_nC(O)R⁶, (CH₂)_nNHSO₂R⁶, NHCONR⁴R⁵, imidazole which is unsubstituted or substituted, imidazolide which is unsubstituted or substituted, oxadiazole which is unsubstituted or substituted, amidoxime and amidine; wherein R⁴, R⁵ and R⁶ are as defined in claim 1.

4. A compound according to claim 1 wherein the pyrrolopyrimidine is of formula (Ib)

wherein R¹, R² and R³ are as defined in claim 1; and

P2 is an unsaturated C6 heterocyclic group which contains one nitrogen atom and which is unsubstituted or substituted.

5. A compound according to claim 1 or 4 wherein the pyrrolopyrimidine is of formula (Ib')

wherein R¹, R² and R³ are as defined in claim 1 and R¹⁵ is selected from H, Ci-C₆ alkyl which is unsubstituted or substituted, OR⁶, halogen, CN, CONR⁴R⁵ and NR⁴R⁵, wherein R⁴, R⁵ and R⁶ are as defined in claim 1.

6. A compound according to claim 1 which is selected from

9-Methyl- 1 -(4-phenethyl-piperazin- 1 -yl)-9H-2,4,9-triaza-fluorene

9-Methyl-6-nitro-l-{4-[2-(4-nitro-phenyl)-ethyl]-piperazin-l-yl}-9H-2,4_J9- triaza-fluorene l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9-methyl-6-nitro-9H-

2,4,9-triaza-fluorene

6-Bromo-l - {4-[2-(3 ,4-difluoro-phenyl)-ethyl]-piperazin- 1 -yl} -9-methyl-

9H-2,4,9-triaza-fluorene l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9-methyl-9H-2,4,9- triaza-fluorene-6-sulfonic acid dimethylamide l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9-methyl-9H-2,4,9- triaza-fluorene-6-sulfonic acid methylamide

1 - {4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin- 1 -yl} -6-nitro-9H-2,4,9- triaza-fluorene

9-Benzyl-l-{4-[2-(3,4-difluoro-phenyl)-ethyl]-piperazin-l-yl}-6-nitro-9H-

2,4,9-triaza-fluorene

1 - {4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l -yl} -9H-2,4,9-triaza- fluorene-6-sulfonic acid benzylamide l-{4-[2-(3,4-Difluόro-phenyl)-ethyl]-piperazin-l-yl}-6-(πiorpholine-4- sulfonyl)-9H-2,4,9-triaza-fluorene

(1 - {4-[2-(3 ,4-Difluoro-phenyl)-ethyl]-piperazin- 1 -yl} -6-nitro-2,4,9-triaza- fluoren-9-yl)-acetic acid ethyl ester

1 - {4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin- 1 -yl} -9H-2,4,9-triaza- fluoren-6-ylamine l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9H-2,4,9-triaza- fluorene-6-sulfonic acid phenylamide

1 - {4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin- 1 -yl } -6-methoxy-9H-2,4,9- triaza-fluorene

N4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9H-

2,4,9-triaza-fluoren-6-yl)-acetamide

N-( 1 - {4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin- 1 -yl} -9H-2,4,9-triaza- fluoren-6-yl)-methanesulfonamide l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-6-trifluoromethoxy-

9H-2,4,9-triaza-fluorene .

5-Chloro-l-{4-[2-(3,4-difluoro-phenyl)-ethyl]-piperazin-l-yl}-9H-2,4,9- triaza-fluorene l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-6-(pyrrolidine-l- sulfonyl)-9H-2,4,9-triaza-fluorene

N-(l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9H-2,4,9-triaza- fluoren-6-yl)-benzenesulfonamide

3-(l - {4-[2-(3,4-Difluoro-ρhenyl)-ethyl]-piperazin- 1 -yl} -9H-2,4,9-triaza- fluoren-6-yl)- 1 , 1 -dimethyl-urea

N-(l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9H-2,4,9-triaza- fluoren-6-yl)-2-methoxy-acetamide

Cyclohexanecarboxylic acid (l-{4-[2-(3,4-difluoro-phenyl)-ethyl]- piperazin-l-yl}-9H-2,4,9-triaza-fluoren-6-yl)-amide

N-(l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9H-2,4,9-triaza- fluoren-6-yl)-nicotinamide 1 - {4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin- 1 -yl} -9H-2,4,9-triaza- • fluorene-6-carboxylic acid methyl ester

1 - {4-[2-(3,4-Difluoro-phenyl)-ethyl]-piρerazin- 1 -yl} -9H-2,4,9-triaza- fluorene-5-carbonitrile

( 1 - {4-[2-(3 ,4-Difluoro-phenyl)-emyl]-piperazin- 1 -yl} -9H-2,4,9-triaza- fluoren-6-yl)-pyrrolidin- 1 -yl-methanone

1 - {4-[2-(3 ,4-Difluoro-phenyl)-ethyl]-piperazin- 1 -yl} -6-methoxy-9H-2,4,9- triaza-fluoren-5-ylamine l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9H-2,4,9-triaza- fluorene-5-carboxylic acid; hydrochloride l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9H-2,4,9-triaza- fluorene-5-carboxylic acid amide

N-(l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9H-2,4,9-triaza- fluoren-6-yl)-4-dimemylarnino-benzarnide

N-(l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9H-2,4,9-triaza- fluoren-6-yl)-2-phenyl-acetamide l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9H-2,4,9-triaza- fluorene-6-carboxylic acid (2-methoxy-ethyl)-amide l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9-methyl-5-nitro-9H-

2,4,9-triaza-fluorene

1 - {4-[2-(3 ,4-Difluoro-phenyl)-ethyl]-piperazin- 1 -yl} -9H-2,4,9-triaza- fluorene-6-sulfonic acid amide

Benzyl-(l-{4-[2-(3,4-difluoro-phenyl)-ethyl]-piperazin-

1 -yl} -9H-2,4,9-triaza-fluoren-6-yl)-amine

4-Chloro-N-(l - {4-[2-(3,4-difluoro-phenyl)-ethyl]-piperazin-l -yl} -9H-

2,4,9-triaza-fluoren-6-yl)-benzamide

N-(l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9H-2,4,9-triaza- fluoren-6-yl)-4-methyl-benzamide

N-(I- {4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l -yl} -9H-2,4,9-triaza- fluoren-6-yl)-C-phenyl-methanesulfonamide

N-(I- {4-[2-(3,4-Difluoro-phenyl)-etliyl]-piperazin-l -yl} -9H-2,4,9-triaza- fluoren-6-yl)-2-phenoxy-acetamide

N-(l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9H-2,4,9-triaza- fluoren-6-yl)-succinamic acid methyl ester

(1 - {4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l -yl} -6-nitro-2,4,9-triaza- fluoren-9-yl)-acetonitrile l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9H-2,4,9-triaza- fluorene-6-carboxylic acid, sodium salt l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-3-methyl-9H-2,4,9- triaza-fluorene

1 - {4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l -yl} -3-pyridin-2-yl-9H-

2,4,9-triaza-fluorene

(l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9H-2,4,9-triaza- fluoren-3 -ylmethyl)-dimethyl-amine

1 - {4-[2-(3 ,4-Difluoro-phenyl)-ethyl]-piperazin-l -yl} -3-morpholin-4- ylmethyl-6-nitro-9H-2,4,9-triaza-fluorene

1 - {4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l -yl} -5-nitro-9H-2,4,9- triaza-fluorene

1 - {4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin- 1 -yl} -9H-2,4,9-triaza- fluorene-6-carboxylic acid cyclohexylamide l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9H-2,4,9-triaza- fluorene-5-carboxylic acid pyridin-4-ylamide

1 - {4-[2-(3 ,4-Difluoro-phenyl)-ethyl]-piperazin- 1 -yl} -9H-2,4,9-triaza- fluoren-5-ylamine

9-Benzyl- 1 - {4-[2-(3,4-difluoro-phenyl)-ethyl]-piperazin- 1 -yl} -5-nitro-9H-

2,4,9-triaza-fluorene l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9H-2,4,9-triaza- fluorene-5-carboxylic acid pyridin-2-ylamide l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9-methyl-9H-2,4,9- triaza-fluorene-5-carbonitrile

N-(I- {4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l -yl} -9H-2,4,9-triaza- fluoren-5-yl)-acetamide N-(l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9H-2,4,9-triaza- fluoren-5-yl)-benzamide

1 - {4-[2-(3,4-Difluoro-phenyl)-ethyl]-piρerazin-l -yl} -9-methyl-9H-2 ,4,9- triaza-fluorene-6-carboxylic acid methyl ester l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9-methyl-9H-2,4,9- triaza-fluorene-5-carboxylic acid amide

1 - {4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l -yl} -6-methoxy-9H-2,4,9- triaza-fluorene-5-sulfonic acid amide

1 - {4-[2-(3 ,4-Difluoro-phenyl)-ethyl]-piperazin- 1 -yl} -9H-2,4,9-triaza- fluorene-6-carboxylic acid dimethylamide l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9H-2,4,9-triaza- fluorene-6-carboxylic acid methylamide

9-(4-Chloro-benzyl)- 1 - {4-[2-(3 ,4-difluoro-phenyl)-ethyl]-piperazin- 1 -yl} -

5-nitro-9H-2,4,9-triaza-fluorene

1 - {4-[2-(3 ,4-Difluoro-phenyl)-ethyl]-piperazin-l -yl} -9-(4-methoxy- benzyl)-5-nitro-9H-2,4,9-triaza-fluorene

1 - {4-[2-(3 ,4-Difluoro-phenyl)-ethyl]-piperazin- 1 -yl } -9H-2,4,9-triaza- fluorene-6-carboxylic acid amide

1 - {4-[2-(3 ,4-Difluoro-phenyl)-ethyl]-piperazin-l -yl} -9H-2,4,9-triaza- fluoren-6-ol

6-Nitro- 1 -(4-quinolin-4-ylmethyl-piperazin- 1 -yl)-9H-2,4,9-triaza-fluorene

6-Nitro- 1 -(4-quinolin-2-ylmethyl-piperazin- 1 -yl)-9H-2,4,9-triaza-fluorene l-{4-[2-(3,4-Difluoro-plienyl)-ethyl]-piperazm-l-yl}-7-methoxy-9H-2,4,9- triaza-fluorene '

1 - {4-[2-(3 ,4-Difluoro-phenyl)-ethyl]-piperazin- 1 -yl} -7-methoxy-8-nitro-

9H-2,4,9-triaza-fluorene

(9-Benzyl-l-{4-[2-(3,4-difluoro-phenyl)-ethyl]-piperazin-l-yl}-9H-2,4,6,9- tetraaza-fluoren-5-yl)-dimethyl-amine l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9-methyl-9H-2,4,6,9- tetraaza-fluorene

5-Chloro-l-{4-[2-(3,4-difluoro-phenyl)-ethyl]-piperazin-l-yl}-9-methyl- 9H-2,4,6,9-tetraaza-fluorene

(l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9-methyl-9H-

2,4,6,9-tetraaza-fluoren-5-yl)-dimethyl-amine

(1- {4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l -yl}-9-methyl-9H-

2,4,6,9-tetraaza-fluoren-5-yl)-isopropyl-amine

( l . {4-[2-(3 ,4-Difluoro-phenyl)-ethyl]-piperazin- 1 -yl} -9-methyl-9H-

2,4,6,9-tetraaza-fluoren-5-yl)-methyl-amine

(l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9-methyl-9H-

2,4,6,94e1xaaza-fluoren-5-yl)-pyridin-2-ylmethyl-aπiine l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9-methyl-5- moφholin-4-yl-9H-2,4,6,9-tetraaza-fluorene l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-5,9-dimethyl-9H-

2,4,6,9-tetraaza-fluorene

(l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9-metliyl-9H-

2,4,6,9-tetraaza-fluoren-5-yl)-ethyl-amine

Benzyl-(l-{4-[2-(3,4-difluoro-phenyl)-ethyl]-piperazin-l-yl}-9-methyl-9H-

2,4,6,9-tetraaza-fluoren-5-yl)-methyl-amine

1 - {4-[2-(3 ,4-Difluoro-phenyl)-ethyl]-piperazin- 1 -yl} -9-methyl-5-(4- methyl-piperazin- 1 -yl)-9H-2,4,6,9-tetraaza-fluorene

1 - {4-[2-(3 ,4-Difluoro-phenyl)-ethyl]-piperazin-l -yl} -9-methyl-5-piperidin- l-yl-9H-2,4,6,9-tetraaza-fluorene l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9H-2,4,5,9-tetraaza- fluorene

8- {4-[2-(3 ,4-Difluoro-phenyl)-ethyl]-piperazin- 1 -yl} -2,9-dimethyl-9H- l,5,7,9-tetraaza-fluorene-4-carboxylic acid amide

8-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-2,9-dimethyl-9H- l,5,7,9-tetraaza-fluorene-4-carboxylic acid amide

8- {4-[2-(3 ,4-Difluoro-phenyl)-ethyl]-piperazin- 1 -yl} -2,9-dimethyl-6- morpholin-4-ylmethyl-9H-l ,5,7,9-tetraaza-fluorene-4-carboxylic acid ethyl ester

8- {4-[2-(3 ,4-Difluoro-phenyl)-ethyl]-piperazin- 1 -yl} -9-methyl-9H- 1 ,5,7,9- tetraaza-fluorene-4-carbonitrile

8- {4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin- 1 -yl} -9-methyl-6- morpholin-4-ylmethyl-9H-l,5,7,9-tetraaza-fluorene-4-carbonitrile

8- {4-[2-(3 ,4-Difluoro-phenyl)-ethyl]-piperazin- 1 -yl} -9-methyl-9H-l ,5,7,9- tetraaza-fluorene-4-carboxylic acid amide

8- {4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l -yl} -9-methyl-6- morpholin-4-ylmethyl-9H-l ,5,7,9-tetraaza-fluorene-4-carboxylic acid amide

8-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-2,9-dimethyl-6- moφholin-4-ylmethyl-9H- 1 ,5,7,9-tetraaza-ftuorene-4-carboxylic acid amide

1 - {4-[2-(3 ,4-Difluoro-phenyl)-ethyl] -piperazin- 1 -yl } -9-methyl-5- thiomoφholin-4-yl-9H-2,4,6,9-tetraaza-fluorene l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-5-(2,6-dimethyl- morpholin-4-yl)-9-methyl-9H-2,4,6,9-tetraaza-fluorene

1 - {4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l -yl} -3-morpholin-4- ylmethyl-6,8-dinitro-9H-2,4,9-triaza-fluorene

(l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-6-nitro-9H-2,4,9- triaza-fluoren-3 -ylmethyl)-dimethyl-amine l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-3-(4-methyl- piperazin- 1 -ylmethyl)-6-nitro-9H-2,4, 9-triaza-fluorene

4-(l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-5-nitro-2,4,9- triaza-fluoren-9-ylmethyl)-benzoic acid methyl ester l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9-(3-methoxy- benzyl)-5-nitro-9H-2,4,9-triaza-fluorene

1 - {4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l -yl} -9-ethyl-5-nitro-9H-

2,4,9-triaza-fluorene

1 - {4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l -yl} -9-isopropyl-5-nitro-

9H-2,4,9-triaza-fluorene

1 - {4-[2-(3 ,4-Difluoro-phenyl)-ethyl]-piperazin- 1 -yl} -9-isobutyl-5-nitro-

9H-2,4,9-triaza-fluorene l-{4-[2-(3,4-Difluoro-plienyl)-ethyl]-piperazin-l-yl}-5-methyl-9H-2,4,9- triaza-fluorene

1 - {4-[2-(3 ,4-Difluoro-phenyl)-ethyl]-piperazin- 1 -yl } -5-nitro-9-pyridin-3 - ylmethyl-9H-2,4,9-triaza-fluorene l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-5-nitro-9-phenethyl-

9H-2,4,9-triaza-fluorene l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-5-nitro-9-pyridin-4- ylmethyl-9H-2,4,9-triaza-fluorene

1 - {4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin- 1 -yl} -5-

(4,5-dihydro-lH-imidazol-2-yl)-9-methyl-9H-2,4,9-triaza-fluorene

2-(l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-6-hydroxy-9H-

2,4,9-triaza-fluoren-5-yl)- 1 -morpholin-4-yl-ethanethione

1 - {4-[2-(3 ,4-Difluoro-phenyl)-ethyl]-piperazin- 1 -yl} -5- fluoro-9-methyl-9H-2,4,9-triaza-fluorene

9-(2,6-Dichloro-benzyl)-l-{4-[2-(3,4-difluoro-phenyl)-ethyl]-piperazin-l- yl} -5-nitro-9H-2,4,9-triaza-fluorene

N-(l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9-methyl-9H-

2,4,9-triaza-fluoren-5-ylmethyl)- acetamide l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9-methyl-9H-2,4,9- triaza-fluorene-5-carboxylic acid ethylamide

(5-Carbamoyl-l-(4-[2-(3,4-difluoro-phenyl)-ethyl]-piperazin-l-yl}-2,4,9- triaza-fluoren-9-yl)-acetic acid ethyl ester

N-(l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9-methyl-9H-

2,4,9-triaza-fluoren-5-ylmethyl)-methanesulfonamide

1 - {4-[2-(3 ,4-Difluoro-phenyl)-ethyl]-piperazin- 1 -yl} -9-methyl-9H-2,4,9- triaza-fluorene-5-carboxylic acid (3-nitro-phenyl)-amide l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9-(2-moφholin-4-yl-

2-oxo-ethyl)-9H-2,4,9-triaza-fluorene-5-carbonitrile

9-Cyanomethyl-l-{4-[2-(3,4-difluoro-phenyl)-ethyl]-piperazin-l-yl}-9H-

2,4, 9-triaza-fluorene-5-carbonitrile l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9-metliyl-5-(l- methyl-4,5-dihydro-lH-imidazol-2-yl)-9H-2,4,9-triaza-fluorene l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-N-hydroxy-9-methy l-9H-2,4,9-triaza-fluorene-5-0-Acetoxy-carboxamidine l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9-methyl-5-(l- methyl-lH-imidazol-2-yl)-9H-2,4,9-triaza-fluorene

2-(5-Cyano-l-{4-[2-(3,4-difluoro-phenyl)-ethyl]-piperazin-l-yl}-2,4,9- triaza-fluoren-9-yl)-N,N-dimethyl-acetarnide l_{4_[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9-methyl-9H-2,4,9- triaza-fluorene-5-carboxylic acid (pyridin-2-ylmethyl)-amide

1 - {4-[2-(3 ,4-Difluoro-phenyl)-ethyl]-piperazin- 1 -yl} -9H-2,4,9-triaza- fluorene-5-carboxylic acid dimethylamide

1 - {4-[2-(3 ,4-Difluoro-phenyl)-ethyl]-piperazin-l -yl} -9- dimethylcarbamoylmethyl-9H-2,4,9-triaza-fluorene-5-carboxylic acid amide l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9-methyl-9H-2,4,9- triaza-fluorene-5-carboxylic acid propylamide

1 - {4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l -yl} -9-pyridin-4-ylmethyl-

9H-2,4,9-triaza-fluorene-5-carbonitrile l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9-pyridin-4-ylmethyl-

9H-2,4,9-triaza-fluorene-5-carboxylic acid amide l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9-methyl-9H-2,4,9- triaza-fluorene-5-carboxylic acid 2,3-dimethoxy-benzylamide

(l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9-methyl-9H-2,4,9- triaza-fluoren-5-yl)-(4-methyl-piperazin- 1 -yl)-methanone

(l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9-methyl-9H-2,4,9- triaza-fluoren-5-yl)-moφholin-4-yl-methanone l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9-methyl-5-(5- methyl-[l,2,4]oxadiazol-3-yl)-9H-2,4,9-triaza-fluorene l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9-methyl-3- morpholin-4-ylmethyl-9H-2,4,9-triaza-fluorene-5-carbonitrile l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-N-hydroxy-9-methyl- 9H-2,4,9-triaza-fluorene-5-carboxamidine

3-Azidomethyl-l-{4-[2-(3,4-difluoro-phenyl)-ethyl]-piperazin-l-yl}-9- methyl-9H-2,4,9-triaza-fluorene-5-carbonitrile

3-Aminomethyl-l-{4-[2-(3,4-difluoro-phenyl)-ethyl]-piperazin-l-yl}-9- methyl~9H-2,4,9-triaza-fluorene-5-carbonitrile

3-Diethylaminomethyl-l-{4-[2-(3,4-difluoro-phenyl)-ethyl]-piperazin-l- yl}-9-methyl-9H-2,4,9-triaza-fluorene-5-carbonitrile l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9-methyl-3- morpholin-4-ylmethyl-9H-2,4,9-triaza-fluorene-5-carboxylic acid amide l-{4-[2-(3,4-Difluoro-phenyl)-ethyl]-piperazin-l-yl}-9-methyl-9H-2,4,9- triaza-fluorene-5-carboxamidine and the pharmaceutically acceptable salts thereof.

7. A pharmaceutical composition which comprises a pharmaceutically acceptable carrier or diluent and, as an active ingredient, a compound as defined in any one of claims 1 to 6.

8. A process for producing a compound as defined in claim 1, which process comprises treating a compound of formula (II):

wherein R¹, R³ and P are as defined in claim 1, with a compound of formula (III)

wherein R² is as defined in claim 1, in an organic solvent in the presence of a base.

9. A compound as defined in any one of claims 1 to 6 for use in a method of medical treatment of the human or animal body by therapy.

10. A compound as claimed in claim 9 for use as an inhibitor of MRP or as an LTC₄ efflux inhibitor.

11. A compound as claimed in claim 9 or 10 for use as a modulator of multidrug resistance, in potentiating the cytotoxicity of a chemotherapeutic agent, in treating a multi-drug resistant tumour or in enhancing the net absorption, distribution, metabolism or elimination characteristics of a therapeutic agent, in treating inflammation or bronchoconstriction, in treating HIV infection, in treating pneumonia or in treating a patient suffering from epilepsy.

12. Use of a compound as defined in claim 1 in the manufacture of a medicament for use as an inhibitor of MRP or as an LTC₄ efflux inhibitor.

13. Use according to claim 16 wherein the medicament is for use as an inhibitor of MRPl.

14. Use of a compound as defined in claim 1 in the manufacture of a medicament for use as a modulator of multidrug resistance, in potentiating the cytotoxicity of a chemotherapeutic agent, in potentiating the therapeutic effect of a drug directed against a multidrug resistant pathogen, in treating a multi-drug resistant tumour or in enhancing the net absorption, distribution, metabolism or elimination characteristics of a therapeutic agent, in treating asthma or other respiratory disease, in treating HTV infection, in treating pneumonia or in treating a patient suffering from epilepsy.

15. A method of treating a patient in need of an inhibitor of MRP, which method comprises administering thereto a compound as defined in claim 1.

16. A method of modulating MRP mediated MDR in the treatment of a tumour, which method comprises administering to a patient harbouring a tumour which expresses MRP mediated MDR a therapeutically effective amount of a compound as defined in any one of the claims 1 to 10.

17. A method of potentiating the cytotoxicity of an agent which is cytotoxic to a tumor cell, which method comprises administering to a patient in need thereof a therapeutically effective amount of a compound as defined in any one of claims 1 to 6.

101

Ar¹ is the same or different when more than one is present within a given substituent group and is an unsaturated C₆-CiO membered carbocylic group or an unsaturated 5-11 membered heterocycle, either of which is unsubstituted or substituted; p is an integer of 1 to 6; n is the same or different when more than one is present within a given substituent group and is 0 or an integer of 1 to 6; with the proviso that the pyrrolepyrimidine compound of formula (I) is other than l-(4- benzyl-piperazm-l-yl)-9H-2,4,9-triaza-fluorene; and the pharmaceutically acceptable salts thereof, have activity as inhibitors of MRP (multidrug resistant protein) and may thus be used to modulate multidrug resistance, for instance in potentiating the cytotoxicity of a chemotherapeutic agent.