SYNTHESIS AND BIOLOGICAL-ACTIVITY OF PYRAZOLOPYRIMIDINES

A series of 1-(4-substituted phenyl/benzoyl)-5-(4-substituted phenyl) pyrazolo(3,4-d) pyrimidin-4-oxo-6-thiones (19-33) were synthesized by the cyclization of ethyl 1-(4-substituted phenyl/-benzoyl)-5-(4-substi tuted phenyl) thioureidopyrazole-4-carboxylates (4-18). Condensation o f 19-33 with chloroacetic acid in alcoholic sodium hydroxide furnish e d 1-(4-substituted phenyl/benzoyl)-5-(4-substituted phenyl) pyrazolo ( 4,3-d) pyrimidin-4-oxo-6-thioacetic acids (34-48), which on reduction with sodium borohydride, followed by cyclization using acetic anhydrid e and pyridine afforded 5H-thiazolido (3,2-a)-8-(4-substituted phenyl/ benzoyl)-pyrazolo(4,3-e)-4-(4-substituted phenyl)pyrimidyl-1,5-diones (49-63). All the compounds were screened for their antimicrobial activ ity against Staphylococcus aureus, Escherichia coli and Candida albica ns. Compound 51 showed most significant antifungal activity (zone of i nhibition, 34 mm). None of the compounds have shown any significant an tibacterial activity.