Antitumoral 5,8-dihydrodiazaanthracenes

Abstract: Azaanthracene-triones of the formula: (in which: R¹, R², R⁴ and R⁵ are the same or are different and each is a hydrogen atom or a lower alkyl group; R³ is a hydrogen atom, a lower alkyl group, a phenyl group or an amino-substituted phenyl gro up; and X is a -CH-, =N- or -NH-, whereby the ring containing the group X is a benzene, pyridine or dihydropyridene ring) have antitumoral activity.

Description: This invention relates to antitumoral compounds and to pharmaceutical compositions containing them. Diazaquinomicyn A is a natural 1,8-diazaanthraquinone found during the routine study of secondary metabolites from bacteria. [S. Omura, et. al., J. Antibiotics, 35 , 1425 (1982); and S. Omura et. al., Tetrahedron Letters, 24 , 3643 (1963)]. It exhibits good activity against Gram positive bacteria, due to its capacity to inhibit the thymidylate synthetase [S. Omura, et. al., J. Antibiotics, 38 , 1016 (2985); and M. Murata et. al T. Miyasaka, H. Tanaka, S. Omura, J. Antibiotics, 38 , 1025 (1985)]. However, Diazaquinomycine A is inactive as an antitumoral agent. Dinzaquinomycine A derivatives as antibacterials and anticancer agents are reported in Japanese Kokaï 63/79830, see Chen Abs 110(1989) 134971. It has now been found, in accordance with the present invention, that certain azaanthracene-triones, as hereinafter defined, possess antitumoral activity. According to the invention, therefore, there are provided azaanthracene triones of the general formula: in which:- R 1 , R 2 , R 4 and R 5 are the same or are different and each is a hydrogen atom or a lower (C 1 -C 6 ) alkyl group; and R 3 is a hydrogen atom, a lower (C 1 -C 6 ) alkyl group, or a phenyl or amino-substituted phenyl group (preferably a dialkylamino substituted phenyl group), at least one of R 1 , R 2 , R 3 , R 4 and R 5 being other than hydrogen. The invention also provides pharmaceutical compositions comprising a compound of formula (I) in association with a pharmaceutical carrier or diluent. The invention further provides the use of a compound of formula (I) in the manufacture of an antitumoral composition. Finally, the invention provides a method for the treatment of tumors using compounds of formula (I). The compounds of this invention are 5,8-dihydro-1H-1,8-diazaanthracene 2,9,10-triones. The compounds of formulae (I) may be prepared by Diels-Alder addition of an N,N-dimethylhydrazone of an appropriately substituted alkenal, followed by later treatment if necessary. Thus, the compounds may be prepared by reaction of a dimethylhydrazone of the formula: with an azanaphthoquinone of the formula: The starting materials are known or may be prepared using well-established technique. Thus, for example the dienophile, 4-methyl-(1H)-quinoline-2,5,8-trione, may be obtained by acetoacetylation of 2,5-dimethoxyaniline with 2,2,6-trimethyl-4H-1,3-dioxin-4-one, followed by Knorr cyclization with sulfuric acid, demethylation with hydrobromic acid and oxidation with potassium dichromate in an acidic medium. The starting dienophile, 3-ethyl-1H-quinoline-2,5,8-trione, may be obtained through Vilsmeier-Haack formylation of 2,5-dimethoxybutyranilide, followed by acidic hydrolysis and oxidative demethylation with cerium ammonium nitrate. Diels-Alder reaction between these dienophiles and N,N-dimethylhydrazones (Helv. Chim Acta, 71 , 486) of 2-butenal, 2-methyl-2-pentenal, 3-phenyl-2-propenal, or 3-(4-dimethylamino-phenyl)-2-propenal affords the partially oxidised 3,8-dihydro adducts. In all cases, the Diels-Alder adducts are accompanied by secondary products formed in the addition of dimethylamine to the C 6 position of the starting quinone. In order that the invention may be well understood the following Examples are given by way of illustration only. Melting points are uncorrected, and were determined in open capillary tubes, using a Buchi immersion apparatus. Combustion elemental analyses were obtained using a Perkin Elmer 2400 CHN analyzer. Spectroscopic data were obtained with the following instruments: IR, Perkin Elmer 577 and Buck Scientific 500; NMR, Varian VXR-300 (300 MHz for 1 H and 75 MHz for 13 C) and Bruker Ac-250 MHz for 1 H and 63 MHz for 13 C). The assignments indicated with * and ** can be interchanged. Example 1 - Synthesis of 4,6-dimethyl-5-5,8-dihydro-1H-1,8-diazaanthracene-2,9,10-trione (1) To a solution of 4-methyl-1H-quinoline-2,5,8-trione (196) mg, 1 mmol) in dry chloroform (130 ml) under nitrogen was added 159 mg (1.14 mmol) of 2-methyl-2-pentenal dimethylhydrazone. The solution was stirred at room temperature for 5 minutes. After evaporation of the solvent, the residue was purified by column chromatography on silica gel, eluting with dichloromethane/ethyl acetate (6:4) to give 33 mg of unreacted hydrazone, 133 mg (45%) of 1 and 105 mg of 6-dimethylamino-4-methyl-1H-quinoline-1,5,8-trione. Melting point:220-223°C. IR(KBr): 3640-3060 (N-H); 1650 (C=O) cm -1 . 1 H-Nmr (300 MHz, CDCl 3 ):6.65 (m, 2H, C 3 -H and N 8 -H); 6.10 (dd. 1H, J 7.8 =4.5 Hz and J=1.2 Hz, C 7 -H): 3.65 (t, 1H, J=4.5 Hz, C 5 -H); 2.62 (d, 3H, J=1.2 Hz, C 4 -CH 3 ); 1.73 (d, 3H, J=1.2 Hz, C 6 -CH 3 ); 1.56 (dq, 2H, J=7.5 and 4.5 Hz, C 5 -CH 2 -CH 3 ); 0.81 (t, 3II, J=7.5 Hz, C 5 -CH 2 -CH 3 )ppm. 13 C-Nmr (75.4 MHz, CDCl 3 ): 183.08 (C 9 ) ; 175.79 (C 10 ); 160.83 (C 2 ) ; 152.03 (C 4 ); 137.11 (C 8a )*; 136.33 (C 9a )*; 127.76 (C 3 ); 119.49 (C 7 ); 115.46 (C 6 ); 114.93 (C 4a ); 111.51 (C 10a ); 36.43 (C 5 ); 25.46 (C 5 -CH 2 -CH 3 ); 22.53 (C 4 -CH 3 ); 18.68(C 6 -CH 3 ); 9.27 (C 5 -CH 2 -CH 3 )ppm. Example 2 - Synthesis of 4-methyl-5-phenyl-5,8-dihydro-1H-1,8-diazaanthracene-2,9,10-trione (2) A solution of 233 mg (1.34 mmol) of trans-cinnamaldehyde N,N-dimethylhydrazone was added to a solution of 4-methyl-1H-quinoline-2,5,8-trione (127 mg, 0.67 mmol) in dry chloroform (120 ml). The reaction was stirred under nitrogen at room temperature for 3 days, with periodical additions of solvent (100 ml each 12 h). A further amount of 166 mg (0.61 mmol) of the hydrazone was added, and the reaction was refluxed for 24 h and evaporated to dryness, and the residue was purified by silica gel chromatography using a gradient elution, starting with neat dichloromethane to dichloromethane/ethyl acetate (7:3), to yield 204 mg of the starting diene, 72 mg (35%) of 2 and 160 mg of 6-dimethylamino-4-methyl-1H-quinoline-2,5,8-trione. Melting point, 206°C. IR (KBr): 3400 (NH), 1660, 1655, 1600 (C=O)cm -1 . 1 H-Nmr (300 MHz, d 5 -pyridine) δ : 10.40 (d, 1H, J=4.0 Hz, Ng-H); 7.69 (dd, 2H, J 2',3' = 8.0 Hz, J 2',4' = 1.0 Hz, C 2, -H, C 6' -H); 7.41 (t, 2H, J = 8.0 Hz, C 3' -H, C 5' -H); 7.25 (tt, J 4',3' = 7.8 Hz, J 4',2' = 1.1 Hz, C 4' -H); 6.70 (m, 2H, C 3 -H, C 7 -H); 5.17 (m, 1H, C 6 -H); 5.11 (d, 1H, J = 5.0 Hz, C 5 -H), 2.46 (d, 3H, J = 1.0 Hz, C 4 -CH 3 )ppm. Example 3 - Synthesis of 5-(4--Dimethylamino-phenyl) 4-methyl-5,8-dihydro-1H-1,8-diazaanthracene-2,9,10-trione (3). A solution of 41.5 mg (2.2 mmol) of 4-methyl-1H-quinoline-2,5,8-trione in dry chloroform (130 ml) and 524 mg (2.4 mmol) of N,N-dimethylhydrazone of p -dimethylaminocinnamaldehyde was stirred under reflux during four days. After evaporation of the solvent, the residue was purified by silica gel chromatography using gradient elution from dichloromethane to dichloromethane/ethyl acetate (7:3), to yield 80 mg (11%) of 3 and 313 mg of 6-dimethylamino-4-methyl-1H-quinoline-2,5,8-trione. Melting point: 252-256°C. IR (KBr) : 3630-3100 (NH), 1650, 1640, 1635 (C=O)cm- 1 . 1 H-Nmr (300 MHz, d 5 -pyridine); 10.24 (d, 1H, J=3.0 Hz, Ng-H); 7.62 (d, 2H, J=8.8 Hz, C 2 '-H, C 6' -H); 6.85 (d, 2H, J=8.8 Hz, C 3' -H, C 5' -H); 6.76 (m, C 7 -H); 6.74 (s, 1H, C 3 -H); 2.78 (s, 6H, N(CH 3 ) 2 ); 2.54 (s, 3H, C 4 -CH 3 )ppm. (The signal of C 6 -H is included in the water signal). BIOLOGICAL ACTIVITY Compounds were diluted in DMSO/MeOH/Acetone (1:4.5:4.5) and they were tested at different concentrations. The solvent was allowed to evaporate before the cells wer seeded. The following antitumoral assay, employing the current screening protocol has been carried out using the following cell: P-388 (lymphoid neoplasm from DBA/2 mouse). Assay against P-388 cells (lymphoidneoplasm from DBA/2 mouse) P-388 cells were seeded into 16 mm wells at 1x10 4 cells per well in 1 ml aliquots of MEM 10C containing different concentrations of the compound. All determinations were carried out in triplicate. As separate set of cultures without drug was counted daily to ensure that the cells remained in exponential growth over the period of observation. After three days of incubation, cells were counted and the IC 50 was determined. COMPOUNDS IC 50 ∂g/ml 1 1 2 0.25 3 20

Claims: Azaanthracene-triones of the formula: in which: R 1 , R 2 , R 4 and R 5 are the same or are different and each is a hydrogen atom or a (C 1 -C 6 ) alkyl group; and R 3 is a hydrogen atom, a (C 1 -C 6 ) alkyl group, a phenyl group or an amino-substituted phenyl group. Compounds as claimed in claim 1 as specifically disclosed in any of the examples herein. A pharmaceutical composition comprising a compound as claimed in claim 1 or claim 2 in association with a pharmaceutical carrier or diluent. The use of a compound as claimed in claim 1 in the manufacture of an antitumoral composition.

Inventors: ALONSO MIGUEL A, AVENDANO CARMEN, ESPADA MODESTA, GARCIA-GRAVALOS DOLORES, MENENDEZ JOSE C, OCANA BLANCA, PEREZ JOSE M, ALONSO, MIGUEL A, AVENDANO, CARMEN, ESPADA, MODESTA, GARCIA-GRAVALOS, DOLORES, MENENDEZ, JOSE C, OCANA, BLANCA, PEREZ, JOSE M., ALONSO, MIGUEL A UNIVERSIDAD COMPLUTENSE DE MADRID, AVENDANO, CARMEN UNIVERSIDAD COMPLUTENSE DE MADRID, ESPADA, MODESTA UNIVERSIDAD COMPLUTENSE DE MADRID, GARCIA-GRAVALOS, DOLORES PHARMA MAR S.A., MENENDEZ, JOSE C UNIVERSIDAD COMPLUTENSE DE MADRID, OCANA, BLANCA UNIVERSIDAD COMPLUTENSE DE MADRID, PEREZ, JOSE M. UNIVERSIDAD COMPLUTENSE DE MADRID
Applicants: UNIV MADRID COMPLUTENSE, UNIVERSIDAD COMPLUTENSE DE MADRID
Application year: 1993
Main classification: C07D471
IPC codes: A61P35, A61K31, C07D471, C07D221