Synthesis and analgesic evaluation of some 5-[beta-(10-phenothiazinyl)ethyl]-1-(acyl)-1,2,3,4-tetrazoles.

A series of novel 5[beta-(phenothiazinyl-10-yl)ethyl]-1-(acyl)-1,2,3,4-tetrazoles (3-14) have been synthesized via condensation of 5-[beta-(phenothiazinyl-10-yl)ethyl]-1-2,3,4-tetrazole (2) with various acylating/sulphonating reagents. 5-[beta-(phenothiazinyl-10-yl)ethyl]-1-2,3,4-tetrazole was synthesized by cyanoethylation of phenothiazine with acrylonitrile and Triton B, followed by the cycloaddition of 3-(phenothiazin-10-yl)-propionitrile (1) with sodium azide and ammonium chloride. The compounds were screened for analgesic activity, anti-inflammatory activity and ulcerogenicity index. Out of the 12 compounds synthesized, compound (5) 5[beta-(phenothiazinyl-10-yl)ethyl]-1-(benzoyl)-1,2,3,4-tetrazole, compound (11) 5[beta-(phenothiazinyl-10-yl)ethyl]-1-(p-tolyl)-1,2,3,4-tetrazole showed promising analgesic activity and compound (6) 5[beta-(phenothiazinyl-10-yl)ethyl]-1-(p-chlorobenzoyl)-1,2,3,4-tetrazole and compound (8) 5[beta-(phenothiazinyl-10-yl)ethyl]-1-(p-nitrobenzoyl)-1,2,3,4-tetrazole showed promising anti-inflammatory activity.