Purine Analogues as Amplifiers of Phleomycin. IV. Some Pyrazolo[3,4-d]pyrimidine, Imidazo[4,5-b]-pyridine, Imidazo[4,5-c]pyridine and Quinazoline Derivatives

Abstract

1-Methyl-1H-pyrazolo[3,4-d]pyrimidine-4(5H)-thione (1b), its 1-phenyl analogue (1c), 1H-pyrazolo- [3,4-dlpyrimidine-4,6(5H,7H)-dithione (2a), its 1-methyl (2b) and 1-phenyl (2c) derivatives, 1H-imidazo[4,5-b and 4,5-clpyridine-2(3H)-thiones (5) and (6), and quinazoline-4(3H)-thione (9) react with simple alkyl halides, 2-chloroacetamide, 2-chloro-N-methylacetamide or 2-bromopropionamide to give the corresponding thioethers (3e-n), (4a-1), (7a-c), (8a-d) and (10). The unmethylated amides among these show dual NH peaks in their n.m.r. spectra. Activities as amplifiers of phleomycin against E. coli are tabulated and discussed.