Synthesis of 2-benzylthiopyrimidinyl pyrazole analogs and their antimicrobial activities

Abstract

Reaction of 4-chloro-2-benzylthiopyrimidine (1) with hydrazine hydrate gave 4-hydrazino-2-benzylthiopyrimidine (2). Further, reaction of 2 with arylideneacetophenones, acetylacetone and ethyl acetoacetate in ethanol in presence of a catalytic amount of acetic acid furnished the target compounds 1 -(2-benzylthiopyrimidin-4-yl)-3, 5 diaryl-2- pyrazolines 3(a-d), 1-(2-benzylthiopyrimidin-4-yl)-3, 5-dimethylpyrazole (4) and 1-(2- benzylthiopyrimidin-4-yl)-3-methylpyrazolin-5-one (5) respectively in 45-75% yield. The structure of new compounds have been elucidated by various spectroscopic techniques. The synthesized compounds were screened for antibacterial and antifungal activities. Among synthesized compounds, 3b and 3d exhibited good activity against bacteria S. aureus and E. coli and the remaining compounds have shown moderate antibacterial and antifungal activity.