Synthesis of 1,3,4-thiadiazole-[3,2,-a]-s-triazine-5,7-dithione derivatives and their pharmacological evaluation.

2-Mercapto-6-phenyl-1,3,4-thiadiazole-(3,2-a)-s-triazine-5,7-dithione (1) was converted to 2-[3-carboxyl-2-methyl-1-mercapto]-6-phenyl-1,3,4-thiadiazole-(3,2-a)-s- triazine-5,6 dithione (2) and 2-thioethanoic acid-6-phenyl-1,3,4-thiadiazole-(3, 2-a)-s-triazine-5,7-dithione (4). This on reaction with o-phenylenediamine/ethylenediamine/o-aminophenol/o-aminothiophenol and polyphosphoric acid yielded compounds 3 (a-d) and 5 (a-d). The compounds 1,2,4,3 (a-d) and 5 (a-d) were evaluated for their anti-inflammatory activity against carrageenan induced paw oedema. The compounds found potent were further tested for their antiwrithmogenic activity in albino mice. Two compounds (2,3c) exhibited significant anti-inflammatory activity, also showed protection against aconitine induced writhing response, with high approximate LD50 values.