Synthesis of Some Novel Substituted Purine Derivatives As Potential Anticancer, Anti-HIV-1 and Antimicrobial Agents

In search of novel purine antimetabolites, a series of 8‐substituted methylxanthine derivatives was prepared in order to explore their in vitro anticancer, anti‐HIV‐1 and antimicrobial activities. The target compounds include: 8‐[(3‐substituted‐4‐oxo‐thiazolidin‐2‐ylidene)hydrazino]‐1,3‐dimethyl (or 1,3,7‐trimethyl)‐3,7‐dihydropurine‐2,6‐diones 5a–e, 8‐[(3,4‐disubstituted 2,3‐dihydrothiazol‐2‐ylidene)hydrazino]‐1,3,7‐trimethyl‐3,7‐dihydropurine‐2,6‐diones 6a–d and 8‐(5‐amino‐3‐arylpyrazol‐1‐yl)‐1,3‐dimethyl‐ (or 1,3,7‐trimethyl)‐3,7‐dihydropurine‐2,6‐diones 7a–g. The in vitro anticancer results revealed that compound 5d exhibited a super sensitivity profile towards leukemia K‐562 with a GI50 value of