GB2175587A - Benzisoindoloisoquinoline derivatives - Google Patents

Description

1

SPECIFICATION

Chemical compounds GB 2 175 587 A 1 This invention relatesto new isoquinoline derivatives,to processes for their preparation, to pharmaceutical preparations containing them, and to their use in medicine.

lsoquinoline compounds have been reported in for example EP-A-1 08620 and EP-A-1 61102 as exhibiting anti-cancer activity. We have nowfound certain novel isoquinoline compoundsto possess particularly interesting pharmacological properties, in particular anti-cancer activity. Compounds according tothe invention also have especially useful physico-chemical properties which make them very suitable for pharmaceutical formulation.

The invention thus provides compounds of the general formula (1) R 0 R 6 R 2 R 0 0 14 11 1 5 (l) 20 R 0 R wherein R' is a hydrogen atom or a methyl group; R 2 is a hydrogen atom or a hydroxyl, C1-4 alkoxy or C2-4 alkanoyloxy group; R 3 is a hydrogen atom, or (when R's otherthan a hydrogen atom) optionally a hydroxyl, C1-4 alkoxy orC2-4 alkanoyloxy group, or R 2 and R 3 together are a methylenedioxy group; R 4 is a hydrogen or halogen atom or a methyl g rou p; R 5 and R6 is each a hydrogen atom or a group -OCOCH2NR 7 R8 [where R 7 and R8, which may be the same or different, each is a hydrogen atom or a C3-7 CYCloalkyl group or a straight or branched C1-4 alkyl group optionally substituted by a hydroxyl group, or -NR 7 R8 forms a saturated heterocyclic amino group which has 5-7 ring members and optionally contains in the ring an oxygen or sulphur atom or a group -NH- or-N(R) where R is a C1-4 alkyl group optionally substituted by a hydroxyl group] with the proviso that when one of R5 and R' is a hydrogen atom, the other is a group OCOCH2NR 7 R8; and salts, especially physiologically acceptable salts, thereof.

Compounds of formula (1) may exist as stereoisomers, and the invention is to be understood to include all such isomers of compounds of formula (1), including mixtures thereof.

The compounds of formula (1) mayform saitswith acids. ftwill be appreciated thatJor pharmaceutical use, these salts will be physiologically acceptable, but other salts mayfind useJor example in the preparation of compounds of formula (1) as well as physiologically acceptable saltsthereof.

Suitable physiologically acceptable salts of the compounds of general formula (1) are acid addition salts derived from inorganic and organic acids. Such salts include for example the hydrochlorides, hydrobromides, sulphates, phosphates, maleates, tartrates, citrates, benzoates, acetates, fumarates and succinates of the compounds of formula (1). Hydrochloride salts are particularly important. References hereinafterto compounds of formulaffl are, unlessthe context demands otherwise, to the compounds themselves and to 45 their physiologically acceptable salts.

In general formula (1), the group R' is preferably a methyl group.

The group R 2 may be for example a hydrogen atom or a hydroxyl, methoxy, ethoxy or acetyloxy group, and is preferably a hydrogen atom.

When the group R 3 is a C1-4 alkoxy or C2-4 alkanoyloxy group it may be for example a methoxy, ethoxy or 50 acetyloxy group. R % preferably a hydrogen atom.

In one group of compounds of formula (1) R 2 is a hydrogen atom or a hydroxyl group, particularly a hydrogen atom, and R' is a hydrogen atom.

When the group R'in general formula (1) is a halogen atom it may be a fluorine, chlorine, bromine oriodine atom, in particular a bromine atom.

In general, R % preferably a hydrogen atom or a methyl group. In another preference R 4 is a bromine atom.

Examples of alkyl groups represented by R 7 or R8 in compounds of formula (1) include methyl, ethyl, propyl and butyl, optionally substituted by a hydroxy group,for example 2- hydroxyethy]. When R 7 or R'is a cycloalkyl group it may be for example cyclopropyl.

When-NR 7 W3 in compounds of formula (1) represents a saturated heterocyclic amino group,this may have 5, 60 6 or7 ring members and optionally contains in the ring an oxygen orsulphur atom or a group -NHor-N(R) where R may be for example a methyl or ethyl group optionally substituted by a hydroxyi group e.g.

2-hydroxyethyl. Examples of such groups -NR 7 R'are pyrrolidino, piperidino, hexamethyleneimino, piperazino, N-methylpiperazino, morpholino orthiomorpholino.

In general, the group R'or R' in compounds of formula (1) is preferably a hydrogen atom or a group 65 GB 2 175 587 A -OCOCH2NR'R'whereR 7 and R8 each represents a straight or branched C1-4 alkyl group, particularly an ethyl group.

In particular,the group R5 is preferablya group -OCOCI-12NR 7 R8where R' and R3each represents a straightor branched Cl-4alkyl group and is especially a group -OCOCH2N(CH3)2, -OCOCH2N(CH2CH3)2or -OCOCH2N(CH2CH2CH3)2, particularly -OCOCH2N(CH2CH3)2. The group R6 is preferably a group -OCOCH2N(CH3)2, -OCOCH2N(CH2CH3)2 or OCOCH2N(CH2CH2CH36 or more preferably is a hydrogen atom.

A particularly preferred group of compounds according to the invention has the formula (1a):

R' 0 R6 1 11 1 10 - / \ -1 /6\ - /\ i / \ il N\ % Q a) 14 11 is 15 R 0 R where R' is a hydrogen atom ora methyl group; R 4 is a hydrogen or halogen atom or a methyl group; R5 and R6 is each a hydrogen atom ora group -OCOCH2NIR 7 W' where R 7 and R8, which may bethe sameor 20 different each is a straight or branched C1-4 alkyl group; and the salts, especiallythe physiologically acceptable salts,thereof.

In compounds of formula (1a) R' is preferably a methyl group. R % preferably a bromine atom ora methyl group, or, in particular, a hydrogen atom.

R5 is preferably a group -OCOCH2NR 7 R3whereR 7 and R8 each represents a straight or branched Cl-4alkyl 25 group, especially a methyl, propyl or, in particular, an ethyl group. Particularly preferred R'groups are -OCOCH2N(CH3)2, -OCOCH2N(CH2CH2CH36 and especially -OCOCH2N(CH2CH36 Cs preferably a hydrogen atom.

A particularly important compound of formula (1) is (diethylamino)acetic acid [5,8,13,14-tetrahydro-1 4-methy]-8,13-dioxobenz[5,6]isoindolo[2,1 b]isoquinolin-9-yi] ester and its physiologically acceptable salts, especially the hydrochlorides thereof.

The compounds of formula (1) possess anticancer activity, particularly against tumours such as sarcomas, carcinomas and hepatomas.

Thus, when a compound of formula (1) is administered intra peritonea[ ly, intravenously or orallyto mice with a subcutaneous tumor arising from an implant of S1 80 cells, subsequent examination has shown that 35 tumor growth has been significantly reduced and in some cases total regression of the tumour has occurred.

Activity against L121 0 (Mouse lymphocytic leukaemia, grown ascitally) has also been shown.

According to a further aspect of the present invention we therefore provide a compound of formula (1) for use in the treatment of the human or non-human animal bodyto combat cancer, particularly tumours, therein.

According to a yetfurther aspect of the present invention we provide the use of a compound of formula (1) 40 for the treatment of the human or non-human animal body to combat cancer, particularlytu mours, therein.

According to a stil I further aspect of the present invention we provide the use of a compound of formula (1) forthe manufacture of a therapeutic agentfor the treatment of the human or non-human animal bodyto combat cancer, particularly tumours, therein.

According to a stil I further aspect of the present invention we provide a method of treatment of the human or 45 non-human animal body to combat cancers, particularly tumours, therein, which method comprises administering to the said body an effective amount of a compound of formula (1).

The compounds of formula (1) advantageously have good water solubility which make them very suitable for pharmaceutical formulation.

In afurtherfeature of the present invention we provide a pharmaceutical composition comprising as active 50 ingredienta compound of formula (1) togetherwith one or more pharmaceutical carriers orexcipients.

For pharmaceutical administration a compound of general formula (1) may be incorporated into conventional preparations in eithersolid or liquidform.

The compositions mayforexample, be presented in a form suitablefor oral, rectal,topical or, more preferably, parenteral administration. Suitableforms includeJor example, tablets, capsules, granules, 55 suppositories, creams, ointments and lotions and more particularly suspensions and/or solutions for injection orinfusion.

The active ingredient may be incorporated in excipients customarily employed in pharmaceutical compositions such asJor example, talc, gum arabic, lactose, starch, magnesium stearate, cocoa butter, aqueous or non-aqueous vehicles, fatty substances of animal or vegetable origin, paraffin derivatives, glycols, 60 various wetting, dispersing or emulsifying agents andlor preservatives.

Advantageouslythe compositions maybe formulated as dosage units, each unit being adapted to supply a fixed dose of the compound of formula (1). Suitable dosage units for adults contain from 25 to 1000 mg of the compound of formula (1).

The dosage, which maybe varied according to the particular patientto be treated and complaint concerned, 65 3 GB 2 175 587 A 3 may,forexample, befrom 0.05to 2.5g e.g. 0.1 to 1g in a dayin adults.

Thecompounds useful accordingtothe invention may be prepared bya numberof procees, described inthe following, wherein the various groups and symbols areas defined forformula (1) unless otherwise specified. Inthese processes, hydroxyl groups,where present, may needto be in a protectedform andthefinal step ina process maythus bethe removal of a protecting group.The protecting group may be any suitable hydroxyl protecting groupforexample as described in "Protective Groupsin Organic Synthesis" byTheodoraW. Greene (Wiley- Interscience, NewYork1981) and "Protective Groups in Organic Chemistry" byJ.F.W. McOmie (Plenum Press, London, 1973) and maybe for example a silyl group, e.g. t-butyldimethylsilyl. Standard protection and deprotection procedures may be used, for example those extensively described in the aforementioned textbooks of Greeneand McOmie. Thus for example protectionwith a silyl group maybe 10 achieved byreactionwith a silyl halide in the presenceof a base. Subsequent deprotection maybeachieved using fluoride ions e.g. from a tetraalkylammonium fluoride such astetra-n-butylammonium fluoride. Where mixturesof isomersare obtained using the following processes, individual isomers may beseparated therefrom byconventional means, for example by chromatography using e.g. silica gel.

Acompound offormula (1) inwhich R 4 isa hydrogen atom ora methyl group maybe prepared byreactionof 15 a compound offormula (2) R 1 0 R10 R #. 20 N R 3/ % 0 0 0 # % 0 R' 4 'l 19 (2) 0 R 25 [where R 4 is a hydrogen atom or a methyl group; one of R'and W0 is a group -OCOCH2L (in which L is a displaceable leaving group such as a halogen atom, e.g. a chlorine, bromine or iodine atom, ora hydrocarbyisulphonyloxy group such as methanesulphonyloxy or p- toluenesulphonyloxy) and the other is a hydrogen atom; or both R'and R10 are -OCOCH2L groups] with an amine R 7 R'NH followed by removal of any 30 protecting groups where present.

The reaction may be effected in the presence of a suitable solvent, for example acetonitrite or a ketonesuch asacetone or a substituted am ide e.g. di methylformamide or d imethylacetamide at a temperature from ambienttothereflux.

The intermediates of formula (2) are novel compounds and form a further aspect of the invention.

The intermediates of formula (2) maybe prepared by condensing a quinone of formula (3).

R 9 0 40 11 (3) R 0 45 with a compound of formula (4) R 1 R 2 1 COOH 50 N R3/ \.// \./ \R" (4) 55 (where R" is a hydrogen atom or a group -CHO or-COCH3) in the presence of an alkanoic acid anhydride, such as acetic anhydride, at an elevated temperature e.g. 1000C.

Compounds of formula (4) are either known compounds, or may be prepared using methods analogousto 60 those used forthe preparation of the known compounds.

Intermediates of formula (3) in which R9 and/or R1() is a group -OCOCH2L and Lisa chlorine atom maybe prepared from the corresponding known quinones in which R9 and/or R" is a hydroxyl group, by reaction with chloroacetic anhydride in a solvent such as dioxan in the presence of abase such as 4-dimethylaminopyridine ortriethylamine at ambient temperature. The chlorine atoms in these intermediates of formula (4) may be 65 4 GB 2 175 587 A 4 displaced using conventional proceduresto prepare intermediates of formula (4) in which Lis a leaving group otherthan a chlorine atom.

Alternatively, compounds of formula (2) in which L is a chlorine atom may be prepared by base catalysed acylation of a corresponding compound in which R9 and/or WO is a hydroxyl group, for example using chloroacetic anhydride in the presence of abase such as sodium hydride in a solvent such astetrahydrofuran. Displacement of the chlorine atom using conventional procedures then yields other intermediates of formula (2). The starting materials forthis reaction maybe prepared as described in European PatentApplication Publication No. 161102.

Compounds offormula (1) in which R 4 is a halogen atom may be prepared by halogenating a corresponding compound in which R 4 is a hydrogen atom. Standard halogenation procedures may be usedJor example 10 reaction with a N-chloro, N-bromo or Modoirnide, e.g. N-chloro-, N-bromo- or Modosuccinimide in an inert solventsuch as dichloromethane at ambient temperature, or by reaction with perchloryl f luoride.

Physiologically acceptable salts of the compounds of general formula (1) may be prepared by reaction of a compound of general formula (1) with an appropriate acid in the presence of a suitable solvent, e.g. dioxan or water The following Examples illustrate the invention. All temperatures are in OC.

Intermediate examples Intermediate 1 5-Chloroacetoxy-1,4-naphthalenedione 5-Hydroxy-1,4-naphthalenedione (30g), chloroacetic anhydride (180g) and 4dimethylaminopyridine (6g) in dioxan (750mi) were stirred at room temperature for 30 minutes then poured onto ice and water (about 4 litres) to give a solid which was collected byfiltration, air dried at room temperature (about 2 hours) and then dried under reduced pressure (0. 1 m m) at 50'for 17 hours to give the title compound (44g). A sample was recrystal 1 ised (2x) from ethyl acetate-petroleum ether (b.p. 60-80') to give the title compound m.p. 125-127'(d).25 Intermediate2 5-lodoacetoxy-1,4-naphthalenedione Intermediate 1 (44g) and sodium iodide (909) in acetone (1 500mi) was stirred for 20 hours at room temperature, then poured onto ice and water (about 6 litres) and allowed to stand at room temperature for 1 30 hour to yield a solid which was collected by filtration, air dried for 2 hours and then dried under reduced pressure (0.1 mm) at 60ofor 18 hours to givethe title compound (55.82g). A sample was purified by chromatography on silica eluting with dichloromethane-ethyl acetate (9: 1), followed by recrystallisation from acetone -petroleum ether (b.p. 60-80') to yield the title compound m.p. 124-125'.

Intermediate 3 (1o do)acetic acid, 5,8,13,14-tetrah ydro-8,13-dioxobenz-[5,6]isoin dolo[2, 1-b]isoquinolin-9yl ester Intermediate 2 (27.9g), 2-formyl-1,2,3,4-tetrahydro-3isoquinolinecarboxylic acid (8.35g) and acetic anhydride (420mi) were stirred at 1 00'for 30 minutes then allowed to cool to room temperature and a green precipitate collected by filtration, washed with acetic anhydride, ethyl acetate and ether, then dried (75', 0. 1 mm) to yield 40 the title compound (1 2.07g) m.p. >260'(d).

Intermediate4 5,8-Dichloroacetoxy- 1,4-naphthalenedione 5,8-Dihydroxy-1,4-naphthalenedione (5g), chloroacetic anhydride (60g) and dimethylaminopyridine (2g) in 45 dioxan (250ml) were stirred at room temperature for 25 minutes. The mixture was then poured onto ice and a green solid was collected byfiltration, washed and dried (CaC12, 0-1 MM; then 70'at 0.1 mm for4 hours) to yield the title compound(l 1.3g) Xmax (ethanol) 247 (E,1378),316 (Ell 711 and 399.5nm (Ell 83).

Intermediate 5 5,8-Di-iodoacetoxy- 1,4-naphthalenedione Intermediate 4 (11 g) and sodium iodide (44g) in acetone (550mi) were stirred for 20 hours at room temperature, the acetone was reduced to lowvolume and the resulting mixture was poured onto ice to yield a solid which was collected byfiltration, washed with water and dried to yield the title compound (13.61 g). A sample was purified by chromatography on silica eluting with dichloromethane then dichloromethane-ethyl 55 acetate (95: 1), followed by crystallisation from acetone-petroleum ether (b.p. 60-80o) to give the m.p. 158-1600.

Intermediate 6 (lodo)acetic acid, 5,8,13,14-tetrahydro-8,13-dioxobenz[5, 6]isoindolo[2. 1-b]isoquinoline-9,12-diyl ester Intermediate 5 (6.95g) and 2-formy]-1,2,3,4-tetrahydro-3- isoquinolinecarboxylic acid (1.35g) in acetic anhydride (34mi) were stirred at 1 000for 20 minutes, and then cooled to room temperature for 1 hour.The resulting precipitate was collected by filtration, washed with acetic anhydride, ethyl acetate and then dried (70', 0.1 mm) to yield the title compoundT (3.0g) Xmax (ethanol) 241.5 (E 2 1556), and 385nm (E] 99).

GB 2 175 587 A 5 Intermediate 7 4-Methyltetrahydroisoquinoline-3-carboxylic acid PMethyl(c11)phenylalanine hydrochloride (4g), concentrated hydrochloric acid (20m1) and formaldehyde (6mi) were heated with stirring in an oil bath at 1 00'for3.5h and then evaporated to drynessto give a whitefroth which was dissolved in water (20mi) and the pH adjusted to 4 with 5M NaOH, under nitrogen. The reaction mixture was stored at 5'for 60h afterwhich a precipitated white solid was recovered by filtration, washed with a small quantity of water and dried to yield the title compound (1.965g) m. p. >260'(decomp).

Interrndiate 8 2-Formyl-4-methyltetrahydroisoquinoline-3-carboxylic acid Acetic anhydride (1 9mi) was added to formic acid (1 9mi) and the reaction mixture was allowed to stand at room temperature for 2 min. Intermediate 7 (1.9g) was added and the reaction was stirred at room temperature for 1 h then evaporated to dryness (water pump) and finally dried at 0.1 mm at room temperature overnight. Crystallisation from aqueous methanol gave the title compound (1.1 9g) as a white solid.

Intermediate,9F1 (lodo)acetic acid, 5,8,13,14-tetrahydro14-methyl8,13-dioxobenz[5, 6]isoindolo[2, 1-b]isoquinolin-9-yl ester A mixture of Intermediate 2 (6.8g) and Intermediate 8 (2.4g) in acetic anhydride (30mi) was heated at 1 00'for 0.5h and then cooled. The reaction mixture was stored at Yfor 2h and the solid collected by filtration, washed with acetic anhydride, ethyl acetate and ether, and dried (0.1 mm at 80') to yield the title compound(2.244g) 20 m.P.207-210'(decomp.)k ax 243nm, Ell 945,373nm, E] 142.

Intermediate 10 5,8,13,14-Tetrahydro-9-hydroxy-14-methylbenz[5,6]-isoindolo[2, 1-b]isoquinoline-8,13-dione Aceticanhydride (160mi)wasaddedtoa mixtureof N-formyi-1,2,3,4-tetrahydroisoquinoline-4-methyi-3-carboxylic acid (20g) and 5-hyd roxy-1,4-napthoq u i none (31.78g).The reaction mixturewas heated at 100'for 1/2 h andwasthen leftto cool overnight(16 h)followed by further cooling for 1 h. A precipitate formed which was filtered, and was shown by thin layer chromatography to be a mixture of 9-hydroxy and 12-hydroxy isomers. The isomers were separated by chromatography on silica gel (using dich loromethane as solvent). From the early fractions the 9-hydroxy isomer, which was the 30 minor component, was obtained. The major component, the title compoundwas collected from late fractions, Xmax243nm,Ell 1103,397nm,E,1381.

Intermediate 11 Chloroacetic acid [5,8,13,14-tetrahydro14-methyl8,13-dioxobenz[5,6]-isoindolo[2, 1- b]isoquinolin- 12-ylester Sodium hydride (60% dispersion) was washed with petroleum ether (b.p. 4060') under nitrogen, tetrahydrofuran (1 Oml) was added followed by Intermediate 10 (0.5g) dissolved in tetrahydrofuran (1 Orni). The reaction mixture was stirred for 10 min and chloroacetyl chloride (0.1 5m]) was added. The mixture wasthen stirred fora further 10 min. 2-Propanol (1 mi) was added followed by a small quantity of water, which was 40 added dropwise. The mixture was poured onto ice and extracted with ethyl acetate (x3). Crystallisation occurred on evaporation to lowvolume to yield the title compound (1 68rng) m.p. 218-222o (d).

Intermediate 12 lodoacetic acid, [5,8,13,14-tetrahydro14-methyl-8,13-dioxobenz[5,6]- isoindolo[2, 1-b]isoquinolin- 12-y/] ester 45 Intermediate 11 (2.45g) was dissolved in a cetone (200ml) and sodium iodide (6g) was added. The reaction mixture was stirred for 18 h at room temperature then evaporated to dryness and redissolved in chloroform.

The inorganic material has removed by filtration, and the solution was then evaporated to dryness.

Crystallisation f rom dichloromethane-petroleurn ether (bp 40-60') yielded the title compound m.p. 205-210' (d).

ProductExamples Example 1 (Diethylamino)acetic acid, [5,8,13,14-tetrahydro-8,13dioxobenz[5,6]isoindolo[2, 1-b]isoquinoline-9, 12-diyester Intermediate 6 (1.656g) and diethylamine (0.5mi) in acetone (165mi) were stirred at room temperaturefor 15 minutes. Further diethylamine (0.5mi) was added andthe miturewas stirredfor35 minutesthen acidifiedwith 4N hydrochloric acid and wateradded. The solution was extracted with dicHloromethane andthe organiclayer was discarded. Thesolution wasthen made alkalinewith aqueous saturated sodium bicarboanteand extracted with dichloromethane (3x) to yield the title compound (1.2g). Crystallisation from ether gave the title 60 compound (670rng) m.p. 125-130'; Xnax (ethanol) 243 (Ell 646) and 385nrn (Ell 110); S(MC13) (1,2,1.16) CH3, (2.84,2.8) CH2A3.87,18) OCH2.

6 GB 2 175 587 A Example2 (Diethylamino)acetic acid, [5,8,13,14-tetrahydro-8,13- dioxobenz[5,6]isoindolo[2, 1-b]isoquinoline-9,12-diyl ester, dihydrochloride The compound of Example 1 (600m9) was dissolved in water (60m1) containing Whydrochloric acid (2.28mi) 5 and the solution was freeze-dried to yield the title compound (740mg) X,,,, (water) 246 (Ell 450) and 406,5 rim (Ell 91).

6 Example 3 (Diethylamino)acetic acid, [5,8,13,14-tetrahydro-8,13-dioxobenz[5,6]- isoindolo[2, 1-b]isoquinolin-9-yfl ester Intermediate 3 (5.2g) and diethylamine (5M1) in acetone (1250m1) were stirredat room temperature for 135 10 minutes, then filtered, evaporated and triturated with acetone to give the title compound (2.1 g). A sample was recrystallised from acetone-petroleum ether b.p. 60-80'to give the title compound m.p. 190-192'; Xmz,>,(ethanol) 243.5 (Ell 1071) and 385nm (Ell 177); 6 (CDCI:3)1.17 (CH3, ethyl), 2.84 (CH2),3.85(OCH2).

Example 4 (Diethylamino)acetic acid, [5,8,13,14-tetrahydro-8, 13-dioxobenz[5,6]- isoindolo[2, 1-b]isoquinolin-9-yl ester, hydrochloride The compound of Example 3 (1.875g) was suspended in water (562mi) and Nhydrochloric acid (4.38mi) was added. The mixture was stirred for 15 minutes and further Whydrochloric acid (4.38mi) was added. After stirring fora further 15 minutes the pH was adjusted to 3 and the solution was filtered and freeze-dried to yield 20 the title compound (2.33g) kmax (water) 245 (Ell 577) and 393.5rim (Ell 95).

is Example 5 (Dipropylamino)acetic acid, [5,8,13,14-tetrahydro-8,13dioxobenz[5,6]isoindolo[2. 1-b]isoquinolin-9-yfl ester Intermediate 3 (3g) and dipropylamine (6mi) in acetone (900mi) were stirred at 40-450 for 30 minutes. The solvent was reduced to a low volu me and the crude title compound (2.3g) was collected byfiltration. Recrystallisation from acetone gave the title compound (1.5g) m.p. 199- 201 0, X.. Jethanol) 243.5 (E,1904) and 376nrn (Ell 143), B(MC13) 0.94 (CH3),1.7-1.5 (CH2),2.71 (CH2).

Example 6 (Dipropylamino)acetic acid, [5,8,13,14-tetrahydro-8,13dioxobenz[5,6]-isoindolo[2, 1-b]isoquinolin-9-yl ester, hydrochloride The compound of Example 5 (442rng) in water (200mi) containing N-hydrochloric acid (4mi) was stirredfor90 minutes afterwhich further Whydrochloric acid (2mi) was added. When solution occured,the pH was adjusted to 3, filtered and freeze-dried to give the title compound (682rng) X.,x (water) 2.45.5rim (Ell 293).

Example 7 (Diethylamino)acetic acid, [5,8,13,14-tetrahydro14-methyl-8,13-dioxobenz[5,6]isoindolo[2, 1- b]isoquinolin-9-yfl ester A mixture of Intermediate 9 (2g) and diethylamine (1 m[) in acetone (200m 1) was stirred at 20'for 0.5h, filtered 40 and the filtrate evaporated to dryness and dried (0.1 mm overnight). The solid was dissolved in acetone by heating, the solution was filtered, evaporated to low volume and then allowed to stand at room temperature for 1 h. The resulting precipitated solid was collected byfiltration, washed with a small amount of acetone and dried at 100'(0.1 mm) to yield the title compound (1.1 8g) m.p. 191-192'; Xm,,x 243nm (Ell 974),39Onm (Ell 135); B(C13C13) 1.53 (CH30.18 (CH3, ethyl), 2.87 (CH2,ethyl), 3.85 (OCH2).

Example 8 (Diethylamino)acetic acid, [5,8,13,14-tetrah ydro- 14-meth yl-8,13-dioxobenz[5,6]isoin dolo[2, 1- b]isoquinolin-9-yl ester, h ydrochloride A mixture of the compound of Example 7 (1.1 g), Whydrochloric acid (5mi) and water (1 60mi) was stirred at20' so for 5 mins. Solution was obtained almost immediately. The pH was adjusted to 3 with an approximately 1 molar equivalent of N NaOH. The solution was filtered and freeze-dried and then dried (CaC12, 0.1 mm, 24h) to yield the title compound (1.239) Xm,x 245nrn (Ell 418) 389, (Ell 63).

Example 9 (Dimethylamino)acetic acid, [5,8,13,14-tetrahydro14-methyl-8,3-dioxabenz[5,6]isoindolo[2, 1-b]- isoquinolin-9-yl ester To a suspension of Intermediate 9 (1.59) in acetone (1 20mi) was added to a solution of dimethylamine in acetone (6.45M, 0.9mi). The reaction mixture was stirred at 200for 2h, then filtered and evaporated to dryness to yield a yellow solid which was dried overnightin vacuo. The solid was dissolved in dichloromethane and 60 extracted into 2N hydrochloric acid. An emulsion formed and was dispersed with a large volume of water.The aqueous layerwas basified (10% NaOH) and back extracted into dich 1 oro methane. The organic solution was dried (Na2S04) and evaporated to dryness, giving the title compound(l 08rng) Xm,, 242.6n.m, Ell = 861, 8 (CDC]3) 1.55 (CH3),2.54 [N-(CH3)2],3.69 (COCH2N), 4.94 (CH) 5.22- 5.12 (CH2).

7 GB 2 175 587 A 7 Example 10 (Diethylamino) acetic acid [5,8,13,14-tetrahydro- 14-methyl-8,13-dioxo benz[5,6]isoindolo[2, 1-b]isoquinolin- 12-yfl ester 1 ntermediate 12 (19) a nd diethyla m ine (0.42m1) in acetone (1 00mi) was stirred at room tem perature for 15 mi n.

The resulting solution was then evaporated to dryness under reduced pressure to give an oil which on mixture 5 with ethyl acetate gave a solid which was washed with water and dried. Crystallisation from methyl acetate gave the title compound (41 Orng) m. p 190-193'. X,ax 243nm, Ell 981, MCIDC13) 1.50 (14-CH3) 3.97,4.07 (CH2 Of ester) 1.33 (CH3 of ethyl), 2.99 (CH2 of ethyl).

Example 11 (Diethylamino)acetic acid [5,8,13,14-tetrahydro- 14-methyl-8, 13-dioxobenz[5,6]isoindolo[2, 1-b]isoquinolin- 12-yl] ester, hydrochloride The com pou nd of Exa m pie 10 (375mg). 0. 1 N hydroch loric acid (20m 1) and water (375ml) was stirred at room temperature for 30 min, filtered, and freeze-dried to yield the title compound (40mg) X max 244nm, Ell 4818 15 (CDC13) 1.58 (14-Me) 4.71 (CH2 of ester) 1.71 (CH3 of ethyl) 3.78 (CH2 of ethyl).

Example 12 Suspension forparenteral administration "Active ingreclient" as used in thefollowing may befor examplethe compound of Example 7.

Active ingredient Tween 80 Dimethylformarnide Fresh distilled water Replacement vehicle 10Orng 1 000mg 1000M1 1000M1 Tween80 50mg Sodium chloride 900mg Fresh distil led water to 100M1 30 Method ofpreparation Dissolvetween 80 (10Orng) andthe active ingredient (10Orng) inthe dimethylformamicle. Add this solution to thefresh distilledwater (100mi) using a radial Silversonfitted with an injectiontube. Stirfor30 minutes. Pour the suspension into centrifuge tubes and centrifuge at 300 rpm until the supernatant is clear. Decantthe 35 su pernatant. Resuspend the "cake"with a portion of the replacement vehicle. Make up to 1 00m] with replacement vehicle.

CLAWS 40 1. Compounds of general formula (1) R 6 R 2 /N\ /% R R4 0 R 50 (wherein R' isa hydrogen atom ora methyl group; R 2 is a hydrogen atom or a hydroxy], C1-4 a] koxyorC2-4alkanoyloxy group; R 3 is a hydrogen atom, or (when R 2 is otherthan a hydrogen atom) optionally a hydroxyi, C1-4 alkoxy orC2-4 55 alkanoyloxy group, or R 2 and R 3 together are a methylenedioxy group; R 4 isa hydrogen or halogen atom or a methyl group; R5 and R' is each a hydrogen atom or a group -OCOCH2N R'R' [where Wand R8, which may bethe same or different, each is a hydrogen atom or a C3-7 CYCloalkyl group or a straight or branched Cl-4alkyl group 60 optionally substituted by a hydroxyl group, or-NR7 Wforms a saturated heterocyclic amino group which has 5-7 ring members and optionally contains in the ring an oxygen or sulphur atom or a group -NH- or-N(R) where R is a C1-4 alkyl group optionally substituted by a hydroxyl group] with the proviso that when one of Wand Wis a hydrogen atom,the other is a group -OCOCH2NR 7 R8) and salts thereof.

2. Compounds of formula (1) as claimed in claim 1 wherein at least one of R 5 and R 6 is a group offormula 65 8 GB 2 175 587 A 8 -OCOCH2NR 7 R8 wherein R 7 and R8 are straightor branched Cl-4alkyl groups, and saltsthereof.

3. Compounds of formula (1) as claimed in either one of claims land 2wherein R 2 and R' are hydrogen atoms and R' is a hydrogen or bromine atom or a methyl group, and salts thereof.

4. Compounds as claimed in claim 1 being compounds of general formula (1a) 5 R' R6 / 10 14 11 1 5 R (where R' is a hydrogen atom ora methyl group; R 4 is a hydrogen or halogen atom or a methyl group; R 5 and R 6 is each a hydrogen atom ora group -OCOCH2WRI where R 7 and R8, which may be the sameor different, each is a straight or branched Cl-4 alkyl group) and saltsthereof.

5. Compounds of formula (1 a) as claimed in claim 4wherein R' is a methyl group, R 4 is a hydrogen or bromine atom ora methyl group, R 5 is a group of formula -OCOCH2NR 7 R8, R 6 is a hydrogen atom and R 7 andRa 20 are straight or branched Cl -4 alkyl g rou ps, and salts thereof.

6. A compound as claimed in claim 1 being [5,8,13,14-tetrahydro-14-methyl-8,13-dioxobenz[5,6]isoindolo[2,1b]isoquinol in-9-yi[(diethylamino)acetate ora physiologically acceptable saitthereof.

7. Compounds of general formula (1) (as defined in claim 1) and salts thereof substantially as herein 25 described in an one of the Examples.

8. A pharmaceutical composition comprising as an active ingredient a compound of general formula (1) as defined in claim 1, or a physiologically acceptable saitthereof, togetherwith one or more pharmaceutical carriers or excipients.

9. A process forthe preparation of compounds of general formula (1) comprising at least one of the following steps:

(a) (to prepare a compound of formula (1) wherein R 4 is a hydrogen atom or a methyl group) reacting a compound of general formula (2) is R 1 0 R 1 () 35 R 2 1 11 1 \! // \ 3/ % /\ R # 40 i if r, i R 0 R 9 (wherein R 4 is a hydrogen atom or a methyl group; one of R9 and R10 is a group -OCOCH2L (in which L is a displaceable leaving group) and the other is a hydrogen 45 atom or both R9 and C) are groups -OCOCH2L; R' is as defined in claim 1; R 2 is a protected hydroxyl group or is as defined in claim 1; and R 3 is a protected hydroxyl group or is as defined in claim 1) with an amine of formula R 7 R'NH (wherein R 7 and R'are as defined in claim 1) and subsequently if necessary removing any protecting groups present; (b) (to prepare a compound of formula (1) wherein R 4 is a halogen atom) halogenating a corresponding 5s compound of formula (1) in which R 4 is a hydrogen atom; and (c) converting a compound of formula (1) so obtained into a saitthereof.

10. The use of a compound of general formula (1) (as defined in claim 1) or a physiologically acceptable salt thereof forthe manufacture of a therapeutic agent for the treatment of the human or non-hu man animal body to combat cancertherein.

11. Compounds of general formula (2) 9 GB 2 175 587 A 9 R R 2 R 3 0 R 9 0 R 10 11 1 (wherein R 4 is a hydrogen atom or a methyl group; one of R9 and W' is a group -OCOCH2L (in which L is a displaceable leaving group) and the other is a hydrogen atom or both R' and R10 are g roups-OCOCH2L; R' is as defined in claim 1; R 2 is a protected hyroxyl group or is as defined in claim 1; and R3'is a protected 15 hydroxyl group or is as defined in claim 1).

12. Compounds of general formula (2) (as defined in claim 11) substantially as herein described in the Intermediate Examples.

Printed in the UK for HMSO, D8818935, 10186, 7102. Published by The Patent Office, 25 Southampton Buildings, London, WC2A lAY, from which copies may be obtained.

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