NITROGEN OXIDES OF AZA- AND DIAZA-ANTHRACENEDIONE DERIVATIVES AS ANTITUMOR AGENTS

Abstract: Nitrogen oxides of aza and diaza anthracenediones, particularly 6,9-substituents which are (aminoalkyl)-amino substituents, have antitumor activity in vitro and in vivo.

Description: NITROGEN OXIDES OF AZA- AMD DIAZA-ANTHRACENEDIONE DERI¬ VATIVES AS ANTITUMOR AGENTS This invention is directed to nitrogen oxides of aza and diaza anthracenediones, and more particularly, to 6,9-substituents which are (aminoalkyl)amino substituents. These compounds have been shown to have antitumor activity in vitro and in vivo. Certain 1,4-bis[ (aminoalkyl)amino]anthracene-9,10- diones have been reported which show antitumor activity in clinical trials. Of particular interest has been a et ntrone, 1,4-bis{ [2-(2-hydroxyeth lamino)ethyl]ami- no]anthracene-9,10-dione and mitoxantrone, 5,8-dihy- droxy-1,4-bis{[2-(2-hydroxyethylamino)ethyl]amino]an- thracene-9,10-dione. (Zee-Cheng et al. , J. Med. Chem. , (1978), 2_1, 291-4; Cheng et al., "Progress in Medicinal Chemistry", Ellis, G.P. and West, G.B., eds. ; Elsevier: Amsterdam, 1983; pp. 20, 83 and references cited the¬ rein). Mitoxantrone is a broad spectrum oncolytic agent, whose activity is similar to that of the anthracycline antibiotic doxorubicin. Clinical trials have demonstrated that mitoxantrone has particularly promising activity in the treatment of advanced breast cancer, acute leukemia and lymphoma (Legha, Drugs of Today, (1984), 2JD, 629). Although animal studies have demonstrated a diminished cardiotoxicity in comparison to doxorubicin, some clinical cardiotoxicity has been observed also with mitoxantrone, mostly in patients previously treated with doxorubicin (R. Stuart Harris et al. , Lancet, (1984), 219, and references cited the¬ rein) . SUBSTITUTE SHEET Ametantrone has been reported to be, in animals, about 10-fold less potent and cardiotoxic than mitoxan¬ trone. Because a delayed toxicity is observed only with mitoxantrone after administration of the two drugs by the i.p. route to non-tumor bearing rats at equieffec- tive antitumor dosages, it is suggested that the pre¬ sence of the 5,8-dihydroxy substitution in mitoxantrone might be implicated in the delayed deaths (Corbet et al. , Cancer Chemother. Pharmacol. , (1981), 6_, 161). In addition, both mitoxantrone and ametantrone have a remarkable myelodepressive toxicity and both compounds show cross-resistance to cell hystotypes de¬ veloping resistance against doxorubicin mediated by overexpression of glycoprotein P. Such a resistance, which is named multidrug resistance, involves a number of antitumor antibiotics, among which amsacrine and po- dophyllctoxinic derivatives, and it is one of the main reasons for therapeutical failures in the treatment of solid tumors with said antibiotics. Therefore, search is required for novel anthrace- nedione antitumor agents-, having a higher therapeutical index than mitoxantrone and being effective both in inhibiting or delaying the growth of those solid tumors which are more refractory to chemotherapeutic treatment (such as lung, breast and colon tumors) and against tu- • mor histotypes developing multidrug resistance. In the search for safer, active analogues of anthracenediones, compounds bearing hydroxysubstituents and/or (aminoalkyl)amino side chains at various posi- tions on the anthracene-9,10-dione nucleus have been studied (C.C. Cheng et al., Drugs of the Future, SUBSTITUTE SHEET (1983), , 229) without notable improvement. Aza- and diaza anthracene-9,10-diones such as 6,9- bis(ethoxycarbonylamino)benzo[g]quinoline-5,10-dione (1), 6,9-bis(ethoxycarbonylamino)benzo[gjisoguinoline- 5,10-dione { 2 ) , 6,9-bis(ethoxycarbonylamino)benzo[g]~ quinazoline-5,10-dione (3_) , were disclosed by Potts et al. (Synthesis, (1983, 31). These compounds were repor¬ ted to be related to the antitumor 1,4- bis[ (aminoalkyl)amino]anthracene-9,10-diones; however no antitumor activity data was reported for any of the above compounds. l-[ (aminoalkyl)amino] derivatives {_) of 6,9-dihydroxybenzo[g]isoquinoline-5,10-dione related to mitoxantrone have been disclosed as DNA intercala- tors but they were completely devoid of any "in vitro" or "in vivo" antitumor activity (Crolsy-Delcey et al., Eur. J. Med. Chem., (1988), 2_3, 101-106). The 6,9-bis[ (aminoalkyl)amino]benzo[g]quinoline- 5,10-diones of formulas 5a-d (see Table I) were disclo¬ sed in J. Med. Chem. (1985), 2_8_, 1124-26, where they were referred to as 5,8-bis[ (aminoakyl)amino]-l-azaan- thracenediones. As shown in table II hereinbelow reported the prior art compounds 5_ are clearly less active than the corresponding carbocyclic analogues (jϊ) . In fact, as reported in table II, the compound J5a and 5b are less cytotoxic than the analogues 6 and jjb. Moreover the compound 5a, which is poorly cytotoxic in vitro, is inactive in vivo, and it is both less active and less potent than the carbocyclic analogue jSa. Even though the introduction of an heteroatom is a common process in the medicinal chemistry, its effect SUBSTITUTE SHEET must be evaluated case by case. In this particular case of aza-analogues of anthracenediones the prior art teachings clearly show that the introduction of a nitrogen atom into the anthracenedione skeleton is detrimental for antitumor activity. In fact the aza-substituted anthracenediones are less cytotoxic than the corresponding anthracene¬ diones and inactive "in vivo". Thus a person skilled in the art, would have not considered the introduction of heteroatoms into the anthracenedione skeleton as a possible way to obtain more effective antitumor agents. It is well known that the screening for the disco¬ very of the antitumor agent mitoxantrone (J. Med. Chem., (1978), 2_1^ 291-4) among a number of analogues has been carried out by using the experimental model of murine leukemia P388: this model is then predictive of antitumor activity in humans at least for this class of antitumor antibiotics. Many other clinically active antitumor antibiotics are active on murine leukemias P388 and L1210 such as m-amsacrine and doxorubicin. Moreover mitoxantrone has shown good activity in other significative experimental tumors such as murine Lewis lung carcinoma and MXl human mammary carcinoma. We have now discovered that nitrogen oxides of aza • and diaza anthracene-9,10-diones are active as antitumor agents: they are highly effective against murine leukemias L1210 and P388 and against Lewis lung carcinoma and MXl human mammary carcinoma. Table I Prior art compounds ^»R=CH 2 CH 2 N(CH3> 4b R= CH2CH 2 CH N(Et>2 Ac R= CH 2 CH 2 KHCH 2 CH20H 5ιR=CH2CH 2 N(CH3)2 6ιR s CH 2 CH 2 N(CH3>2 5bR-CH2CH 2 (B)2 6b -CH2CH2N(Eι>2 Se R« CH 2 CH 2 CH2N(CH3)2 «R-CH2CH2NHCX)CH3 Table II Antitumor activity of prior art compounds j5 and against murine L 1210 leukemia (from J. Med. Chem. (1985), 2 , 1124-1126) wherein X, Y and Z are CH, N or N —> 0 thus forming an azine or diazine ring, with the proviso that: - at least one of X, Y and Z is N —> 0; R is hydrogen; aralkyl; (C 2 -C, Q )-alkyl having one or two substituents selected from -OR 1 , -NR 2 R 3 ; (C 2 -C,_)-alkyl chain optionally interrupted by one or two oxygen atoms or by one member selected from the TUTE SHEET group consisting of -N-, cis -CH=CH-, trans -CH=CH-, R* -C=C- and optionally substituted by one or two hydroxy or -NR 2R3 groups; R is hydrogen; phenyl; (C_-C- 0 )-aralkyl; (C.-C,.)-al¬ kyl; or a group of formula: 0 C-H; -AC-R5; -IC-O-R5; C 2 -Cg alkyl optionally substituted by -N-R 2 R 3 ; R 2 and R3, which can be the same or different, are hy¬ drogen; (C.-C. -alkyl; (C 2 -C, Q )-alkyl substituted with one or two hydroxy groups; (C_-C lf .)-aralkyl; phenyl; or one of R 2 or R3 is a group of formula , -C'-R» D , together with the nitrogen atom to which they are linked, form an aziridine ring, or a 5- or 6-membered aromatic or non aromatic heterocyclic ring which might contain another heteroatom such as nitrogen, oxygen or sulfur; 4 R is hydrogen; (C,-C, -alkyl; (C 2 -C. 0 )-hydroxyalkyl; a 2 -C 10 alkyl substituted by NR 2R3; (C.-,-C, 0 )-aralkyl; phenyl; 5 R is (C 1 -C 1Q )-alkyl; (C--C,..)-aralkyl; phenyl; m and n are independently zero or the integers 1 and 2, with the proviso that m and n cannot be zero at the same time; SUBSTITUTE SHEET and the pharmaceutically acceptable salts thereof. The present invention also relates to the tautome- ric forms, the racemic and diastereoisomeric mixtures of the compounds of formula (I) as well as the single enantiomers and diastereoisomers thereof. Examples of pharmaceutically acceptable acids which can salify compounds (I) are inorganic acids, such as hydrochloric, hydrobromic, sulfuric, phospho¬ ric, pyrophosphoric acids or organic acids, such as acetic, propionic, citric, benzoic, lactic, maleic, ma¬ lic, fumaric, succinic, tartaric, glutamic, aspartic, gluconic, ascorbic acids or other conventionally used acids. Specific examples of azine and diazine rings con¬ taining at least one nitrogen-oxide function are those represented by the following formulae: 0 0 0 In compounds (I), the words "phenyl" and "5-6 mem¬ bered heterocyclic ring" mean phenyl rings or heterocy¬ clic rings which can optionally contain substituents such as (C.-C.)-alkyl groups; CF- > ; halogen atoms; ni- tro, amino, acetylamino, formylamino, dimeth lamino, diethylamino, hydroxy, methoxy and ethoxy groups. When in compounds of formula (I) the NR 2R3 substituent is a 5-6 member aromatic or not aromatic heterocyclic ring which might contain another heteroatom such as oxygen, sulfur or nitrogen, preferred examples of said heterocyclic rings containing at least one oxygen or nitrogen atom are 1- imidazolyl, 1-pyrrolyl, 1-tetrahydropyrrolyl, 1-pyrazo- lyl, 1-pyrrolydinyl, 4-morpholin 1, 1-piperidinyl, 1- piperazinyl, l-(4-methyl)piperazinyl, l-(4-benzyl)pipe- razinyl, 4-(3-methoxy)morpholinyl, 4-(3-cyano)morpholi- nyl. Preferred examples of (C_-C, 0 )-aralk l groups are benzyl and 4-methoxybenzyl. Preferred examples of (C.-C, 0 )-alkyl groups are methyl, ethyl, n-propyl, sec-propyl, n-butyl, sec- butyl, tert-butyl, n-hexyl and n-pentyl. When in compounds (I) R is a (C 2 -C 1Q )-alkyl group, optionally interrupted by one or more hetero-atoms, at least 2 carbon atoms are preferably present between said hetero-atoms. Particularly preferred are those compounds of for¬ mula (I) in which R is a substituted (C 2 -C, 0 )-alkyl group, selected from the group consisting of : - residues of formula -(CH_) -OH, wherein p is the integer 2, 3 or 4; - residues of formula -(CH t__)P-NH __ * wherein p is as defi- ned above; - residues of formula -(CH.,) -NR 2R3 wherein p is as de- fined above and R 2 and R3 are (C,-C 8 )-alkyl groups or, taken together with the nitrogen atom, they form an 1- aziridine, 1-pyrrolidine, 4-morpholine, 1-piperazine, 4-methyl-l-piperazine, 4-benzyl-l-piperazine or 1-pipe- , wherein p is as def ne above an R s (C. -Cg ) -a yl or phenyl ; - residues of formula -(CH-) -NH-(CH-) -OH wherein p and q are independently an integer selected from the group of 2,3 or 4; - residues of formula Specific examples preferred compounds of the invention are the following ones: 6,9-bis[N-(2-aminoethyl)aminoJbenzo[g]isoquinoline- 5,10-dione-2-oxide; 6,9-bis[N-(2-dimethylaminoethyl)amino]benzo[g]isoquino- line-5,10-dione-2-oxide; 6,9-biε{N-[2-(2-hydroxyethylamino)ethyl] mino}benzo[g]- isoquinoline-5 ,10-dione-2-oxide; 6 ,9-bis{N-[2-(4-morpholinyl)ethyl] mino}benzo[g]isoqui- noline-5,10-dione-2-oxide; 6,9-biε[N-(2-diethylaminoethyl)amino]benzo[g]isoquino- line-5,10-dione-2-oxide; 6,9-bis{N-[2-(1-pyrrolidinyl)ethyl]amino}benzo[g]iso- quinoline-5,10-dione-2-oxide; 6,9-bis[N-(3-hydroxypropyl)amino] enzo[g]isoquinoline- 5,10-dione-2-oxide; 6 ,9-biε[N-(1,1-bis(hydroxymeth 1)meth l)amino]benzo- [g]isoquinoline-5,10-dione-2-oxide; 6,9-bis{N-[(2-oxotetrahydrofuran-4-yl)methyl]amino]ben- zo[g]isoquinoline-5,10-dione-2-oxide; 6,9-bis{N-[2-(1-aziridinyl)eth l]amino}benzo[g]isoqui- noline-5,10-dione-2-oxide; 6,9-bis[N-(3-aminopropyl)amino]benzo[g]isoquinoline- 5,10-dione-2-oxide; 6,9-bis[N-(4-aminobutyl)amino]benzo[g]isoquinoline- 5,10-dione-2-oxide; 6,9-biε{N-[2-(methylcarbamoylamino)ethyl]amino}benzo- [g]iεoquinoline-5,10-dione-2-oxide; 6,9-biε{N-[2-(phenylcarbamoylamino)ethyl]amino}benzo- [g]iεoquinoline-5,10-dione-2-oxide; 6,9-bis[N-(2-aminoethyl)amino]benzo[g]quinoline-5,10- dione-1-oxide; 6,9-bis[N-(2-dimethylaminoethyl)amino]benzo[g]quinoli- ne-5,10-dione-l-oxide; 6,9-bis{N-[2-(2-hydroxyethylamino)ethyl]amino}benzo[g]- quinoline-5,10-dione-l-oxide; 6,9-bis[N-(2-aminoethyl)amino]benzo[g]quinoxaline-5,10- dione-1-oxide; 6,9-bis[N-(2-aminoethyl)amino]benzo[g]quinoxaline-5,10- dione-1,4-dioxide; 6,9-bis[N-(2-dime hylaminoethyl)amino]benzo[g]quinoxa- line-5,10-dione-l-oxide; 6,9-bis[ -(2-dimeth laminoethyl)amino]benzo[g]quinoxa- line-5,10-dione-l,4-dioxide; 6,9-bis{N-[2-(2-hydroxyethylamino)ethyl]amino}benzo[g]- quinoxaline-5,10-dione-l-oxide; 6,9-bis{N-[2-(2-hydroxyethylamino)ethyl]amino}benzo[g]- quinoxaline-5,10-dione-l,4-dioxide. The compounds of the invention of formula (I) can be prepared by reacting a compound of formula (II) SUBSTITUTE SHEET wherein X, Y and Z are aε defined above; 5 W is a fluorine atom or a group, R being as defined above; with a compound of formula (III) H 2 N-R a (III) wherein Rcl has the same meanings as defined in formula (I) for R or it is a group which may be converted to R, to give a compound of formula (la): and then optionally performing one or more of the fol¬ lowing εteps: a) when Ra β is other than R, converting Ra into R to obtain a compound of formula (I); b) when R is one of the groups defined above for R in compounds of formula (I), and in which case the compounds of formula (la) are the same as the compounds of formula (I), Rcl can be optionally converted into another Rc = l group to give another compound of formula ( i ) ; c) optional salification and/or solvation of the obtained compounds of formula (I) or separation of the isomerε thereof. The reaction of compound (II) with a compound of formula (III) is generally carried out in the presence of a stoichiometric amount or a slight molar excess of compound (III) in a solvent such as methylene chloride, chloroform, 1,1,1-trichloroethane, dimethoxyethane, te- trahydrofur n, dimethylformamide, N,N,N' ,N'-tetrame- thylethylenediamine, pyridine, picoline, quinoline and mixtures thereof, or, if desired, using compound (III) itself as the solvent, optionally in the presence of an inorganic base such as an alkali or alkaline-earth carbonate or hydrogen carbonate or an organic base such as triethylamine or other tertiary amines, at a temperature from 0 C C to the reflux temperature of the solvent. Preferably the reaction is carried out in pyridine at 50 β C, using from 2 to 5 equivalents of compound (III) per equivalent of compound (II). The optional removal of primary- or secondary- a ine protecting groups or hydroxy-protecting groups optionally present in compounds of formula (la) can be carried out according to well-known methods, such as hydrolysis of the esters and amides of compounds of formula (la) with organic or inorganic acids or bases, or selective cleavage of the protecting groups, using suitable reducing and oxidizing agents, the preferred reagent of course depending on the nature of the protecting group. Compounds of formula (II) can be prepared by oxi¬ dizing a compound of formula (IV) wherein X' , Y 1 and Z 1 have the same meanings as X, Y and Z, with the exclusion of N —> 0, so aε to form an azine or diazine ring; W is as defined above; with oxidizing agents such as peracids, peroxides or salts thereof. The oxidation of compounds (IV) to give compounds of formula (II) is generally carried out using a εtoichiometric amount or a slight excess of an oxidizing agent, in a solvent such as chloroform, methylene chloride, 1,2-dichloroethane, acetic acid, optionally in the presence or in the absence of an alkali or alkaline-earth metal carbonate or bicarbo- nate, at a temperature from 0°C to the reflux tempera¬ ture of the solvent and for a time ranging from a few hours to some days, depending on the experimental con¬ ditions. Exampleε of the oxidizing agents which can effec- tively be used to oxidize compounds of formula (IV) to compounds of formula (II) include hydrogen peroxide; peracetic, trifluoroperacetic, perbenzoic and m- chloroperbenzoic acids; monoperoxyphthalic acid or the magnesium salt thereof; persuccinic acid. The reaction is preferably effected using at least 1,2 equivalents of an organic peracid, such as m-chloroperbenzoic acid, per nitrogen-oxide function which is desired, in a solvent such as methylene chloride. Compounds (IV) can be prepared by means of a multi-step procesε, including a Friedel-Crafts conden¬ sation between a compound of formula (V) wherein X ' , Y' and Z ' are as defined above ; with para-difluorobenzene , which resultε in compoundε having the formulae (VI ) and (Via ) (Via) (VI) which are εubsequently subjected to a cyclization reaction to yield a compound of formula (IV) wherein W is fluorine. Alternatively, Friedel-Crafts bis-acyla- tion of a 1,4-dialkoxybenzene with a compound of for¬ mula (V) gives a compound of formula (VII) wherein X', Y 1 and Z' are as defined above; which iε εubsequently reacted with a compound of formula (VIII) wherein R is as defined above, to give a compound of formula (IV) wherein W is -O-S-R y The reaction of a compound of formula (V) with para-difluorobenzene, to give the compounds of formula (VI) and (Via), is generally carried out in the presence of at least two equivalents of a Lewis acid, such aε AlCl^, AlBr- , ZnCl_ and the like. The reaction iε performed preferably uεing para-difluorobenzene aε the εolvent, in the presence of an amount of aluminium trichloride which can range from 2.5 to 4.0 moles per mole of compound (V) at 90°C for some hours. Cyclization of the compounds of formulae (VI) and (Via) to give a compound of formula (IV) in which W is fluorine, can be carried out using condensing agents such as polyphosphoric acid, PPE, sulfuric acid, oleum and the like, at temperature from room temperature to 180°C. Preferably, cyclization is effected using 20% SO- oleum at 140°C for about 10 hourε. Biε-acylation of a 1,4-dialkoxybenzene with a com¬ pound of formula (V) is preferably carried out using 1,4-dimethoxybenzene, in an eutectic mixture of alumi¬ nium chloride and sodium chloride at 180 β C, and it ge- nerally is completed in a few minutes. The reaction of a compound of formula (VII) with a S2ϊϊJsa SΛU.B.i compound of formula (VIII) to give a compound of for- ula (IV) in which W is is effected according to conventional methods. Usually the reaction is carried out in the pre¬ sence of a stoichiometric amount or a slight excess of a compound of formula (VIII) in a solvent, such as methylene chloride, chloroform, dimethoxyethane, tetra- hydrofuran, dimethylformamide, pyridine or mixtures thereof, in the optional presence of an organic or inorganic base, or according to Schotten-Baumann method, at a temperature from 0 β C to the reflux tempe¬ rature of the solvent. Generally the reaction is carried out in pyridine at room temperature and it is complete after 48 hours. Compounds of formula (V) can be prepared from com¬ pounds of formula (IX) wherein X', Y' and Z' are as defined above, by reaction with an appropriate dehydrating agent, such as carboxy- lie acid anhydrides (e.g. acetic or trifluoroacetic anhydrides), carbodiimides, such as N,N'-dicyclohexyl¬ carbodiimide, methoxyacetylene, phosphoric anhydride and the like. Acetic anhydride at a temperature from 80°C to the solvent's reflux temperature, or N,N'-dicyclohexylcar¬ bodiimide in an aprotic solvent at a temperature from SUBSTITUTE SHEET 20°C to the solvent's reflux temperature, are preferred reaction conditions. Compounds (III) and (IX) are known or commercially available. Useful teachings to prepare some compounds of formula (III) can be found in J. Org. Chem. (1959), 24, 818-820; J. Med. Chem. (1980), 33.i 112-117; J. Med. Chem., (1981), 34_, 184-189; Synthetic Com ., (1990), 2 (16), 2559-2564. The evaluation of the biological activity for the compounds of this invention was performed "in vitro" and "in vivo" following the protocols developed by the U.S. National Cancer Institute. The evaluation of the "in vitro" cytotoxic activity of the compounds of the invention was performed using a human colon adenocarcinoma cell line (Lovo) isolated from a metastatic nodule and a subline with aquired resistance to a number of antitumor agents, among which doxorubicin, VP-16 and vincristine. This εubline (named Lovo/DX) εhows reduced accumulation of doxorubicin and overexpression of a protein (Grandi, M. , Geroni, C. , Giuliani, F.C. , British J. Cancer, (1986), 54, 515). The compounds were tested according to the MTT asεay (Moεman, T. "Rapid Colorimetric aεsay for cellular growth and survival: application to proliferation and cytotoxicity assay", J. Immunol. • Methods, (1983), 5, 55-63; Green. L.M. , "Rapid Colorimetric asεay for cell viability; application to the quantitation of cytotoxic and growth inhibitory lymphokineε", J. Immunol. Methodε, (1984), 1J_, 257-268) in comparison with ametantrone and doxorubicin. In general, representative compounds of this invention were equally cytotoxic as ametantrone in the Lovo cell line. For example a representative compound of the invention such as 6,9-bis[N-(2-dimethylamino¬ ethyl)amino]benzo[g]isoquinoline-5,10-dione-2-oxide, described in example 12 of the experimental section, showed an IC 5Q of 0.44 μg/ml (144 hours drug-exposure) while ametantrone in the same experimental conditions showed an IC 5Q of 0.33 ± 0.1 μg/ml. When ametantrone was tested in the Lovo/DX cell line, a resistance index RI (defined as the ratio of the IC,- Q for the resistant cell line to the 1C_ 0 for the sensitive cell line) as high as 101.2 was found, showing that this subline did have an acquired resiεtance to ametantrone. On the other hand a representative compound of the invention such as 6,9-bis[N-(2-dimethylaminoethyl)amino]benzo[g]- isoquinoline-5,10-dione-2-oxide ( s .) (see table III for structures) showed on this resiεtant subline an IC 50 of 2.68 μg/ml with an R.I. of 6.1 while doxorubicin showed on this resistant cell line an IC 5Q of 4.28 ± 1.8 μg/ml and R.I. = 142.7. These in vitro data suggest that representative compounds of this invention may be useful in order to overcome the multidrug resiεtance mediated mechaniεm of tumor resistance. Studies of the biological activity "in vivo" of representative compounds of the invention were performed using the P 388 and L 1210 murine leukemia models. P 388 Murine leukemia cells were intravenously (iv) injected in CD2F1 mice. Treatment was initiated approximately 24 hours after tumor transplantation and SUBSTITUTE SHEET dosages of the drug were administered iv according to preestabliεhed protocols, usually at 3-day intervals. The studieε were done over a 60 day period and the date of death for each animal was recorded. The % T/C was determined using the median survival time (MST) for each group according to the formula % T/C - [(MST treated)/(MST control)] x 100. For example a repreεentative compound of thiε invention, namely 6,9-bis{[2-(amino)ethyl]aminoJbenzo- [g]isoquinoline-5,10-dione-2-oxide as the dimaleate εalt deεcribed in example 13 εhowed an activity εuperior to that of mitoxantrone. Moreover thiε representative compound of the invention showed antileukemic activity over a wide range of well tolerated dosages and in particular it was active at dosages which were lower than the maximum tolerated dose, providing indication for a more favourable therapeutic index in comparison to mitoxantrone; The reεults are shown in table (IV) Table III a R = CH 2 CH 2 N(CH 3 ) 2 b R - CH 2 CH 2 NH 2 (dimaleate salt) Table IV ANTITUMOR ACTIVITY OF THE REPRESENTATIVE COMPOUND OF THE INVENTION 6,9-BIS[N(2-AMINOETHYL)AMINO]BENZO[G]ISO- QUINOLINE-5,10-DIONE-2-OXIDE DIMALEATE (7B) AND MITOXANTRONE (MITOX) AGAINST P 388 MURINE LEUKEMIA (iv/iv 1,4,7) 1) CD2F1 mice were transplanted iv with 10 cells/mou¬ se. Treatment was given iv on days 1,4,7 after tumor transplantation (day 0). 2) Compound lh_ and MITOX were disεolved in εterile wa¬ ter. 3) Median survival time of treated mice/median survival time of controls x 100. 4) Number of toxic deaths/total number of mice. The antitumor activity of representative compounds of this invention was evaluated also in the L 1210 murine leukemia model. L 1210 leukemia cells were intravenouεly (iv) SUBSTITUTE injected in CD2F1 mice and treatment was initiated approximately 24 hours after tumor transplantation. Dosages of the drugs were administered iv according to preestablished protocols, usually at 3-day intervals. The studies were done over a 60-day period and the date of death for each animal was recorded. The % T/C was determined using the median survival time (MST) for each group according to the formula % T/C * [(MST treated)/(MST control)] x 100. The results are shown in table (V) from which the superior antileukemic activity of the representative compound of the invention 6,9-bis[N-(2-aminoethyl)ami¬ no]benzo[g]isoquinoline-5,10-dione-2-oxide dimaleate (7b) of example 13 in compariεon to mitoxantrone is evident. Table V ANTITUMOR ACTIVITY OF THE REPRESENTATIVE COMPOUND OF THE INVENTION 6,9-BIS[N-(2-AMIN0ETHYL)AMINO]BENZO[G]- ISOQUINOLINE-5,10-DIONE-2-OXIDE DIMALEATE (7B) AND MITOXANTRONE (MITOX) AGAINST MURINE LEUKEMIA L1210 (iv/iv 1,4,7) 1 1) CD2F1 mice were transplanted iv with 10 cells/mou- ** se. Treatment was given iv on days 1,4,7 after tumor transplantation (day 0). 2) Compound l _ and MITOX were dissolved in sterile wa¬ ter. 3) Median survival time of treated mice/median survival time of controls x 100. 4) Number of toxic deaths/total number of mice. Representative compounds of the invention, when administered to test animals bearing experimental tumors such as P388/DOXO doxorubicin-resistant murine leukemia P388, Lewis lung carcinoma, human mammary carcinoma MXl, LOVO human colorectal tumor, LOVO/DOXO doxorubicin-resistant human colorectal tumor, induce a statistically significant regression in the experimental tumors compared to the control animals treated with the only vehicle. The activity of the induced regression is directly proportional to the used dosage (pharmacological dose-related effect) and to the dosage scheme (e.g. single administration in the day after tumor transplantation or repeated administrations at days 3, 5, 9 or 3, 5, 9, 14 after the tumor implantation). The compounds of the invention, when administered at their maximum tolerated doses, induce a higher regression of these experimental tumorε than that caused by doxorubicin and mitoxantrone, at their maximum tolerated doses, under the same experimental conditions. Particularly, the compounds of the invention are markedly more effective than the control drugs in inhibiting the growth of solid tumors which are doxorubicin- and mitoxantrone-resistant. Therefore, the available test data prove that the EET compoundε of the invention have the following featureε: - they have a higher therapeutic index than mitoxantro¬ ne, εince the range of therapeutic lly effective to¬ lerated doεeε in the animal iε markedly wider than that of mitoxantrone; - they are effective in inhibiting growth of liquid and solid experimental tumors, such as murine leukemias, murine lung εolid tumorε, human mammary and colon εo- lid tumorε which are predictive of good reεultε in human; - they are effective against experimental solid tumors which are doxorubicin- and mitoxantrone-resistant (multidrug-resiεtant) . Therefore, due to these characteristicε, the com- pounds of the invention are expected to be operative against human leukemias and solid tumors and they can be used as the active ingredients in therapeutical compositions for the regresεion and/or the treatment of tumors in mammals, when administered in amounts ranging from 0.001 g to about 0.4 g per kg body weight per day. A preferred dosage regimen for optimum resultε would be from about 0.001 g to about 0.05 g per kg body weight per day, using unitary doεageε so as to administer from about 0.07 g to about 3.5 g of active compound to a subject of about 70 kg body weight, in a 24 hour period. This dosage regimen can be adjusted to provide optimum therapeutical response. For example, several divided doses can be administered according to the requirements of the therapeutical situation. A remarkable practical advantage is that the active compound can be administered by the oral, intravenouε, " intramuscular or subcutaneous routes. The compositions of the present invention contai¬ ning compounds of formula (I) can be used for the tre¬ atment of blood cancer diseases such as leukemia or other solid and non-solid tumors such as lung carci¬ noma, colon carcinoma, melanocarcinoma and mammary tu¬ mors. Aε used herein, by regression or treatment is me¬ ant arresting or delaying the growth of the tumor. Sui¬ table administration forms for intravenous injection are physiological sterile solutionε. For the intramu¬ scular or intraperitoneal administrations, oily or aqueouε injectable preparationε are alεo suitable, whe¬ reas suitable forms for the oral administrations are liquid or solid preparations such as syrupε, capεuleε, tablets and the like. The invention is further illustrated by the fol¬ lowing examples. EXAMPLE 1 A mixture of pyridine-3,4-dicarboxylic acid (15.33 g) and acetic anhydride (30 ml) is refluxed under stir¬ ring for one hour. After cooling to room temperature, the acetic anhydride excess is distilled off under re¬ duced pressure and the obtained residue is taken up into ethyl ether (60 ml). The separated solid is filte- red and washed with ethyl ether, to yield pyridine-3,4- dicarboxylic acid anhydride (11.72 g); m.p. 76.5- 78.5 β C. EXAMPLE 2 Using pyridine-2,3-dicarboxylic acid or pyrazine- 2,3-dicarboxylic acid in the procedure described in Example 1, pyridine-2,3-dicarboxylic acid anhydride, m.p. 134-136°C, and pyrazine-2,3-dicarboxylic acid anhydride, m.p. 190°C (dec.) are prepared. EXAMPLE 3 A mixture of pyridine-3,4-dicarboxylic acid anhy- dride (2.43 g) and aluminium chloride (8.60 g) in 1,4- difluorobenzene (32 ml), under vigorous stirring, is heated for 12 hours in oil-bath, kept at 110 β C. After recovering the 1,4-difluorobenzene excess by distilla¬ tion, the obtained residue is cooled in ice-bath and carefully treated with ice-water (35 ml) and concentra¬ ted hydrochloric acid (3.6 ml). The obtained precipi¬ tate iε separated by filtration and washed with water to give a mixture of 4-(2' ,5'-difluorobenzoyDpiridine- 3-carboxylic acid and 3-(2* ,5'-difluorobenzoylJpiri- dine-4-carboxylic acid (3.02 g, m.p. 217.5-222°C) . Said acid mixture (3.0 g), without any further purifica¬ tions, is added to 20% SO, oleum (7.5 ml) and the obtained mixture is heated for 2 hrs in oil-bath, kept at 135-140°C. After cooling to room temperature, the mixture is carefully poured into ice (220 ml), neutralized with sodium bicarbonate and extracted with methylene chloride (3 x 60 ml). The combined organic phases are washed with brine and dried over sodium sulfate, then εolvent iε removed under reduced pressure, to give 6,9-difluorobenzo[g]isoquinoline- 5,10-dione in form of a yellow solid; m.p. 199-200°C (2.23 g). • "H-NMR (CDC1 3 )£ : 7.57, , 2H; 8.03, d IH; 9.12, d, IH; 9.54, s, IH. EXAMPLE 4 A mixture of pyridine-2,3-dicarboxylic acid anhy- dride (2.4 g) , aluminium chloride (8.4 g) and 1,4-di- fluorobenzene (35 ml) is reacted according to the pro¬ cedure deεcribed in Example 3, to give a mixture of 3- (2' ,5'-difluorobenzoyl)pyridine-2-carboxylic acid and 2-(2 ' ,5'-difluorobenzoyl)pyridine-3-carboxylic acid (4.1 g). Without further purifications, said acid mixture (0.40 g) in 30% SO, oleum (1.0 ml) is heated for 6 hrs in oil-bath at 155-165 β C. The obtained mixture is εub- sequently treated as described in Example 3, to give 6,9-difluorobenzo[g]quinoline-5,10-dione in form of a yellow solid, m.p. 251-252 β C (0.102 g). EXAMPLE 5 A mixture of pyrazine-2,3-dicarboxylic acid anhy- dride (1.0 g), aluminium chloride (2.3 g) and 1,4-di- fluorobenzene (22 ml) is reacted according to the pro¬ cedure described in Example 3, to give crude 3-(2',5'- difluorobenzoyl)-2-pyrazinecarboxylic acid, which is purified by dissolution in chloroform (85 ml), filtra- tion of the insoluble material and extraction of the chloroform solution with a sodium bicarbonate saturated solution. The combined extracts are acidified with 10% sulfuric acid and extracted with chloroform, to give, after distillation of the solvent, said acid (1.24 g), m.p. 149-150 C C. This compound is then treated (0.28 g) with 30% S0 3 oleum (1.5 ml) at 140 C C for 6 hrs, as described in Example 3, to give 6 / 9- difluorobenzo[g]quinoxaline-5,10-dione in form of a yellow solid, m.p. 230°C (dec.) (0.19 g). EXAMPLE 6 A finely ground mixture of pyridine-3,4-dicarboxy- SUBSTΪTUTE SHEET lie acid anhydride (4.81 g) and 1,4-dimethoxybenzene (3.08 g) iε added in portions in about 3 min to a mel¬ ted mixture of aluminium chloride (60 g) and sodium chloride (12 g) at 180°C. At the end of the addition the mixture is kept at this temperature for 5 more min, then, while it is still hot and fluid, it iε carefully poured into a 0.7N sulfuric acid solution, cooling with an ice-bath. Subsequently the mixture is continuously extracted with chloroform, the chloroform extract is dried, solvent is removed under reduced presεure and the reεidue iε recryεtallized from ethanol, to give 6,9-dihydroxybenzo[g]iεoquinoline-5,10-dione (1.08 g), m.p. 205-207 β C. EXAMPLE 7 Following the procedure described in Example 6 and using pyridine-2,3-dicarboxylic acid anhydride as the starting material, 6,9-dihydroxybenzo[g]quinoline-5,10- dione, m.p. 234-237"C, is prepared. EXAMPLE 8 A solution of 6,9-dihydroxybenzo[g]isoquinoline- 5,10-dione (0.25 g) and p-toluenesulfonyl chloride (0.79 g) in pyridine (10 ml) is stirred at room tempe¬ rature for 48 hrε. After removing pyridine under redu¬ ced pressure, the obtained residue is added with water and the separated solid iε filtered and waεhed with cool ethyl acetate. After recrystallization from a chloroform/ligroin mixture, 6,9-bis(p-toluenesulfonylo- xy)benzo[g]isoquinoline-5,10-dione (0.35 g) , m.p. 201- • 202°C, is obtained. EXAMPLE 9 Following the procedure described in Example 8 and using 6,9-dihydroxybenzo[g]quinoline-5,10-dione as the starting material, 6,9-bis(p-tolueneεulfonyloxy)benzo- [g]quinoline-5,10-dione is prepared. EXAMPLE 10 A solution of 6,9-difluorobenzo[g]iεoquinoline- 5,10-dione (0.97 g) in methylene chloride (40 ml) iε added in portionε to m-chloroperbenzoic acid (1.78 g, titre about 50%) . After about 5 hrε at room tempera¬ ture, more m-chloroperbenzoic acid (0.35 g) iε added and the resulting mixture is left at room temperature for overall 22 hrs. The obtained solution is washed with a sodium bicarbonate saturated solution (3 x 20 ml), the combined aqueous phaseε are re-extracted with methylene chloride (20 ml) and the combined organic phaεes are finally washed with brine. After drying over sodium sulfate and distilling the solvent under reduced pressure, the obtained residue is recrystallized from methylene chloride, to give 6,9-difluorobenzo[g]isoqui- noline-5,10-dione-2-oxide, in form of a yellow solid, m.p. 250.1-252.3 β C (0,75 g). 1 H-NMR (CDCl 3 )t : 7.58, m, 2H; 8.11, d, IH; 8.43, dd, IH; 8.82, dd, IH. EXAMPLE 11 Following similar procedures to those described in Example 10, subjecting the appropriate difluoro- or bis(p-tolueneεulfonyloxy)-derivatives of aza- and diaza-anthracenediones to oxidation with εuitable oxidating agents, the following compounds are prepared: 6,9-difluorobenzo[g]quinoline-5,10-dione-l-oxide; 6,9-bis(p-toluenesulfonylox )benzo[g]quinoline-5,10- dione-1-oxide; 6,9-bis(p-toluenesulfonyloxy)benzo[g]isoquinoline-5,10- SUBSTITUTΞ SHEET dione-2-oxide; EXAMPLE 12 N,N-Dimethylethylenediamine (0.33 ml) is added to a suspension of 6,9-difluorobenzo[g]isoquinoline-5,10- dione-2-oxide (0.20 g) in anhydrouε pyridine (5 ml) kept under εtirring at 67"C. The reaction mixture is kept at this temperature for 5 hrs, then it is left at room temperature overnight. The obtained solution is applied on a silica gel chromatography column, which is eluted first with ethyl acetate, then with 4/1 v/v ethyl acetate/methanol, finally with 16/4/0.2 v/v/v chloroform/ methanol/conc. ammonia. The fractionε from the main blue chromatographic band are combined, concentrated to dryneεs and the residue is taken up into ethyl ether (10 ml), under stirring, to give 6,9- bis[N-(2-dimeth laminoethyl)amino]benzo[g]isoquinoline- 5,10-dione-2-oxide (0.15 g) , m.p. 178 β C. 1 H-NMR (CDC1 3 ) S : 2.40, s, 12H; 2.70, t, 4H; 3.55,q, 4H; 7.35, s, 2H; 8.17, d, IH; 8.35, dd, IH; 9.01, d, IH; 11.10, ra, 2H (exchangeable with D-,0) . U.V. (H 2 0) λ maχ (n ) E 1% (cm): 278 (653); 368 (112); 621 (317); 661 (343). H.P.L.C: Lichrospher 100 RP18 (5 μm) ; eluent 10 mM so- dium heptaneε lfonate + 10 mM KH-,P0 4 in 70/20/10 wa¬ ter/acetonitrile/dioxane, pH ~ 3 with H 3 P0.; flow 1 ml/min. R.t. = 2.85 min. EXAMPLE 13 Following the procedure described in Example 12, by reacting 6,9-difluorobenzo[g]isoquinoline-5,10-dio- ne-2-oxide with 1,2-ethylenediamine, 6,9-bis[N-(2- aminoethyl)amino]benzo[g]isoquinoline-5,10-dione-2- oxide, m.p. 164°C (dec.) is prepared. A solution of this compound (0.35 g) in 1/1 v/v chloroform/methanol (10 ml), kept under stirring in an oil-bath at 60°C, is added with a solution of maleic acid (0.25 g) in methanol (1.5 ml). The reaction mixture is kept at this temperature for 5 min, then it is allowed to cool to room temperature. After two hrs, the separated solid is filtered, washed with methanol (0.5 ml) and ethyl ether and subεequently recrystallized at 70-80°C by dissolution in water (4 ml) and reprecipitation with absolute ethanol (20 ml) to give 6,9-bis[N-(2- aminoethyl)amino]benzo[g]iεoquinoline-5,10-dione-2- oxide dimaleate 1.5 H-,0, m.p. 183.5 β C (dec.) (0.36 g). ■ ' ■ H-NMR (D 2 0) £ : 3.35, m, 4H; 3.85, m, 4H; 6.20, s, 4H; 7.35, s, 2H; 7.97, d, IH; 8.40, dd, IH.; 8.65, d, IH. U.V. (H 2 0) : λ maχ (n ), E 1% (cm): 212 (703); 275 (520); 614 (251); 658 (272). H.P.L.C.: Lichrospher 100 RP18 (5 μm) ; eluent: 10 mM sodium heptanesulfonate + 10 mM KH 2 PO. in 70/20/10 wa¬ ter/acetonitrile/dioxane, pH ~ 3 with H 3 P0 4 ; flow 1 ml/min.; R.t. = 2.74 min. EXAMPLE 14 A 6.9N HCl solution in methanol (0.22 ml) at 0 β C under magnetic stirring, is dropped into a 6,9-bis[N- (2-dimethylaminoethyl)amino]benzo[g]isoquinoline-5,10- dione-2-oxide (0.19 g) solution in anhydrous chloroform (30 ml). After one hour the obtained suspension is di¬ luted with ethyl ether (30 ml) and the separated blue solid is filtered under nitrogen and washed with ethyl ether, to give 6,9-bis[N-(2-dimethylaminoethyl)amino]- benzo[g]isoquinoline-5,10-dione-2-oxide dihydrochloride TE SHEET ( 0.16 g) . " hϊ-NMR (D 2 0) S : 2 . 60 , , 12H; 2.90 , m, 4H; 3 .85 , m, 4H; 7.34 , s , 2H; 7. 95 , d, IH; 8.38 , dd, IH; 8.65 , d, IH. EXAMPLE 15 Following the procedureε described in Example 12, by reacting the appropriate nitrogen oxiieε, prepared in Exampleε 10 and 11, with the εuitable amineε, the following compounds are prepared, which are isolated as free bases: 6,9-bis[N-(2-diethylaminoethyl)amino]benzo[g]isoquino- line-5,10-dione-2-oxide ■ ^-NMR (CDC1 3 ) S : 1.15, t, 12H; 2.63, q, 8H; 2.75, t, 4H; 3.58, q, 4H; 7.36, s, 2H; 8.15, d, IH; 8.35, dd, IH; 9.03, d, IH; 11.15, m, 2H. 6,9-bis{N-[2-(1-pyrrolidinyl)ethyl]amino}benzo[g]iso- quinoline-5,10-dione-2-oxide 1 H-NMR (CDCl 3 )f5 : 1.87, m, 8H; 2.69, m, 8H; 2.85, m, 4H; 3.62, m, 4H; 7.38, ε, 2H; 8.17, d, IH; 8.37, dd, IH; 9.03, d, IH; 11.00, t, IH; 11.11, t, IH. 6,9-biε{N-[2-(4-morpholinyl)ethyl]amino}benzo[g]iεoqui- noline-5,10-dione-2-oxide X H-NMR (CDC1 3 ) £ : 2.55, m, 8H; 2.80, m, 4H; 3.59, m, 4H; 3.78, m, 8H; 7.35, s, 2H; 8.15, d, IH; 8.36, dd, IH; 9.01, d, IH; 10.95-11.03, brt, 2H. 6,9-bis(N-[2-(2-hydroxyeth lamino)ethyl] mino}benzo[g]- isoquinoline-5,10-dione-2-oxide ^-NMR (CDCl 3 ) δ: 2.98, m, 4H; 3.10, m, 4H; 3.55, m, 4H; 3.86, m, 4H; 7.35, s, 2H; ' 8.15, d, IH; 8.38, dd, IH; 9.02, d, IH; 11.15, m, 2H. 6,9-biε{N-[2-(1-aziridinyl)ethyl]amino}benzo[g]iεoqui- noline-5,10-dione-2-oxide 1 H-NMR (CDC1 3 ) S : 1.65, m, 8H; 2.65, m, 4H; 3.60, m, 4H; 7.34, s, 2H; 8.17, d, IH; 8.35, dd, IH; 9.01, d, IH; 11.11, m, 2H. 6 , 9-bis [N- ( 3-hydroxypropyl ) amino ]benzo [ g ] isoquinoline- 5 , 10-dione-2-oxide 1 H-NMR (CDC1 3 ) £ : 2.11, m, 4H; 3.58,m, 4H; 3.65, m, 4H; 7.36, s, 2H; 8.15, d, IH; 8.38, dd, IH; 9.03, d, IH; 11.13, m, 2H. 6 , 9-bis [N- ( 2 -hydroxyethy 1 ) amino ] benzo [g ] iεoquinoline- 5 , 10-dione-2-oxide 1 H-NMR (COC1-) £ : 3.60, m, 4H; 3.69, m, 4H; 7.34, ε, 2H; 8.14, d, IH; 8.37 dd, IH; 9.01, d, IH; 11.15, m, 2H. 6,9-bis[N-(1,1-bis(hydroxymethy1) ethyl)amino]benzo[g]- isoquinoline-5,10-dione-2-oxide 1 H-NMR(CDC1 3 ) δ; 3.80-3.92, m, 10H; 7.34, s, 2H; 8.15, d, IH; 8.36, dd, IH; 9.01, d, IH; 11.13; m, 2H. 6,9-bis[N-(3-aminopropyl)amino]benzo[g]isoquinoline- 5,10-dione-2-oxide; 6,9-bis[N-(4-tert-butoxycarbonylaminoeth l)amino]benzo- [g]isoquinoline-5,10-dione-2-oxide; 6,9-bis{N-[2-(methylcarbamoylamino)ethyl]amino}benzo- [g]iεoquinoline-5,10-dione-2-oxide; 6,9-bis{N-[2-( henylcarbamoylamino)ethyl]amino}benzo- [g]isoquinoline-5,10-dione-2-oxide; 6,9-biε[N-(2-dimethylaminoethyl)amino]benzo[g]quinoli- ne-5,10-dione-l-oxide; 6,9-bis[N-(3-aminopropyl)amino]benzo[g]quinoline-5,10- dione-1-oxide; 6,9-bis{N-[2-(2-hydroxyethylamino)ethyl]amino}benzo[g]- SUBSTITUTE SHEET quinoline-5,10-dione-l-oxide; 6,9-bis[N-(2-aminoethyl)amino]benzo[g]-quinoline-5,10- dione-1-oxide. EXAMPLE 16 By subjecting the appropriate free bases to the salification processes described in Examples 13 and 14, the following maleate or hydrochloride saltε are prepared: 6,9-bis[N-(3-aminopropyl)amino]benzo[g]isoquinoline- 5,10-dione-2-oxide dimaleate ^Η-NMR (D 2 0) ζ : 2.30, m, 4H; 3.37, m, 4H; 3.86, , 4H; 6.23, s, 4H; 7.36, s, 2H; 7.97, d, IH; 8.40, dd, IH; 8.67, d, IH. 6,9-biε[N-(4-aminobutyl)amino]benzo[g]iεoquinoline- 5,10-dione-2-oxide dihydrochloride " hl-NMR (D 2 0) S : 2.18, , 8H; 3.35, m, 4H; 3.84, m, 4H; 7.33, ε, 2H; 7.95, d, IH; 8.38, dd, IH; 8.65, d, IH. 6,9-bis{N-[2-(4-morpholinyl)ethyl]amino}benzo[g]isoqui- noline-5,10-dione-2-oxide dihydrochloride; 6,9-bis[N-(3-aminopropyl)amino]benzo[g]quinoline-5,10- dione-1-oxide dimaleate. 6,9-bis[N-(2-aminoethyl)amino]benzo[g]quinoline-5,10- dione-1-oxide dimaleate.

Claims: CLAIMS 1. Compounds of formula (I): wherein X, Y and Z are CH, N or N —» 0 thus forming an azine or diazine ring, with the proviso that: - at least one of X, Y and Z iε N —■> 0; R iε hydrogen; (C 1 -C- 0 )-alkyl; phenyl; (C--C,.)- aralkyl; (C 2 -C, Q )-alkyl having one or two substituents selected from -OR 1 , -NR 2 R 3 ; (C 2 -C, 0 )-alkyl chain optionally interrupted by one or two oxygen atoms or by one member selected from the group consisting of -N-, cis -CH=CH-, tranε -CH=CH-, R l 4 * -C=C- and optionally substituted by one or two hydroxy or -NR 2R3 groups; R is hydrogen; phenyl; (C_-C 10 )-aralkyl; (C 1 -C- L0 )-al- kyl; or a group of formula: I-H; - 6C-R5; -ftC-O-R5; C 2 -C 8 alkyl optionally substituted by -N-R 2 R 3 ; ET R2 and R3, which can be the same or different, are hy¬ drogen; (C- J -C ^Q )-alkyl; (C 2 -C, Q )-alkyl substituted with one or two hydroxy groups; (C_-C, 0 )-aralkyl; phenyl; or one of R 2 or R3 is a group of formula -Cϋ-H, -ICI-R5, -CH-O-R5, -ICI-NH-R5, , • or R2 and R3, together with the nitrogen atom to which they are linked, form an aziridine ring, or a 5- or 6-membered aromatic or non aromatic heterocyclic ring which might contain another heteroato such as nitrogen, oxygen or εulf r; 4 R lε hydrogen; (C,-C, -alkyl; (C 2 -C, Q )-hydrox alk l; a C 2 -C 10 alkyl substituted by NR 2R3; (C.-C,..)-aralkyl; phenyl; - 8C-H, 8C-R 5 , - 8C-O-R ." -B i R is (C.-C-J Q )-alkyl; (C_-C., 0 )-ar lkyl; phenyl; m and n are independently zero or the integers 1 and 2, with the proviso that m and n cannot be zero at the same time; and the pharmaceutically acceptable salts thereof. 2. Compounds as claimed in claim 1 wherein X and Z are CH and Y is N - O. 3. Compounds as claimed in claim 1, in which R is a substituted (C 2 -C, 0 )-alkyl group, selected from the group consisting of : - residues of formula -(CH 2 ) -OH, wherein p is an inte- ger from 2 to 4; - residues of formula -(CH_) -NH- wherein p iε aε defi- ned above; - residues of formula -(CH,) -NR 2R3 wherein p is as de- fined above and R 2 and R3 are (C.-Cg)-alkyl groups or, taken together with the nitrogen atom, they form an aziridine, pyrrolidine, morpholine, piperazine, N- methylpiperazine, N-benzylpiperazine or piperidine ring; 0 - residues of formula -(CH,) -NH-C-NH-R , wherein p is as defined above and R 5 is (C 1 -C 8 )-alkyl or phenyl; - residueε of formula -(CH,) -NH-(CH 2 ) -OH wherein p and q are independently an integer 2 to 4; reεidueε of formula 4. A compound of claim 1 which iε 6,9-biε[N-(2- di ethylaminoethyl)amino]benzo[g]iεoquinoline-5,10- dione-2-oxide. 5. A compound of claim 1 which is 6,9-bis[N-(2- aminoethyl)amino]benzo[g]isoquinoline-5,10-dione-2-' oxide dimaleate. 6. A procesε of the preparation of compoundε of claim 1, which comprises reacting a compound of formula (II): wherein X, Y and Z are as defined above; W is a fluorine atom or a -O- Qs-R5 group, R5 being as SUBSTIT defined above; with a compound of formula (III) H 2 N-R a (III) wherein R CL has the same meanings as defined in formula (I) for R or it iε a group which may be converted to R, to give a compound of formula (la): and then optionally performing one or more of the fol¬ lowing steps: a) when OL is other than R, converting RC-t into R to obtain a compound of formula (I); b) when R is one of the groups defined above for R in compounds of formula (I), and in which case 1 the compounds of formula (la) are the same as the compounds of formula (I), RcL can be optionally converted into another group to give another compound of formula (i); c) optional salification and/or solvation of the obtained compounds of formula (I) or separation of the isomers thereof. 7. Pharmaceutical compositions containing as the active ingredient a compound as claimed in claims 1-5, in admixture with appropriate excipients. 8. The use of the compounds as claimed in claims 1-5 for the preparation of an antitumor medicament.

Inventors: GANDOLFI CARMELO A, MENTA ERNESTO, OLIVA AMBROGIO, SPINELLI SILVANO, TOGNELLA SERGIO, GANDOLFI, CARMELO, A., MENTA, ERNESTO, OLIVA, AMBROGIO, SPINELLI, SILVANO, TOGNELLA, SERGIO
Applicants: BOEHRINGER MANNHEIM ITALIA, BOEHRINGER MANNHEIM ITALIA S.P.A.
Application year: 1992
Main classification: C07D241
IPC codes: A61K31, A61P35, C07D221, C07D241, C07D401, C07D403, C07D405