Design, synthesis, and antimicrobial activity of some new pyrazolo[3,4-d]pyrimidines

2-Benzyl- and 2-aryloxymethyl-3-amino-1-phenyl-pyrazolo[3,4-d]pyrimidine-4-ones 5a-f have been synthesized by reacting the corresponding arylacetylamino derivatives 3a-f with hydrazine hydrate. Thionation of compounds 5d-f by action of P2S5 in pyridine yielded 2-aryloxy-methyl-3-amino-1-pheny-lpyrazolo[3,4-d]pyrimidin-4-thions 6a-c. 2,5-Diphenyl-2,3-dihydro-1H-pyrazolo[5',1':4:5]pyrazolo[3,4-d]pyrimidine-8-one (8) was also obtained via reaction of ethyl-2-cinnamoylamino-1-phenyl-pyrazole-4-car-boxylate (7) with hydrazine hydrate. The prepared compounds were screened in vitro for their antimicrobial activity. Some of the tested compounds were found to be active at 100 mug/ml compared with reference compounds (Ampicillin and Trivid) as antibacterial agents and claforan as antifungal agent. (C) 2003 Wiley Periodicals, Inc.