Synthesis of some new s-alkylated 1,2,4-triazoles, their mannich bases and their biological activities

Abstract

A series of 1-(4-methoxyphenyl)-2-[5-{(biphenyl-4-yloxy)methyl}4-(substituted phenyl)-3-mercapto-(4H)-1,2,4-triazol-3-ylthio)] ethanones (6a-6s) and 4-(substituted phenyl)-3-(morpholin/pyrrolidin-4-ylmethylthio)-5-(4-phenylphenoxymethyl)-4H-1,2,4-triazoles (7a-7e) were synthesized in order to obtain new compounds with potent anti-inflammatory and analgesic activity with insignificant ulceration. Among the synthesized compounds, (6c), (6e), (6g) and (6l) from triazole series and (7b) and (7e) from Mannich base series were found to exhibit significant anti-inflammatory activity with 59.69, 59.69, 64.69, 79.84, 54.54, 79.69% and 52.55, 57.50, 72.52, 83.03, 60.06, 84.08% inhibition of paw edema at 3 h and 5 h respectively, in comparison to the standard drug ibuprofen (78.93 and 82.58% at 3 h and 5 h). The active compounds were further tested for their analgesic activity and gastric ulceration study. Compounds 6g, 7b and 7e exhibited significant analgesic activity with reaction time (3.60, 3.22, 3.88 s) respectively at 60 min. without causing any gastric irritation. These compounds were also screened for their in vitro antimicrobial activity, Compounds 6f, 6g, 6h, 6l, 6o, 6p, 7a, 7b and 7c showed significant zone of inhibition against various antimicrobial stains. It is concluded that the compounds 6g, 7b and 7e possess a good spectrum of activities. Compound 7e may be considered potent for development of better anti-inflammatory agent. The antimicrobial activity revealed that most of the compounds showed moderate to significant activity. Compounds containing nitro, chloro, bromo and fluoro group showing better activity. All the compounds from 7a, 7b and 7e were active against gram positive bacteria (S. aureus).