Synthesis of 5-substituted-3-methylsulfanyl-1-(2,4-dinitro phenyl)- 1H-pyrazole-4-carboxylic Acid Ethyl Esters as New Analgesic and Anti-inflammatory Agents

A new series of 5-substituted-3-methylsulfanyl-1-(2,4-dinitro phenyl)-1H-pyrazole-4-carboxylic acid ethyl esters were synthesized by reacting the amino group of 5-amino-3-methylsulfanyl-1-(2,4-dinitro phenyl)-1H-pyrazole-4-carboxylic acid ethyl ester with acid anhydrides, acid chlorides and phenyl dithiocarbamates. The title compounds were investigated for analgesic, anti-inflammatory and ulcerogenic behaviour. The compound 5-benzoylamino-3-methylsulfanyl-1-(2,4-dinitro phenyl)-1H-pyrazole-4-carboxylic acid ethyl ester (3c) emerged as the active compound and exhibiting imperative analgesic and anti-inflammatory activity. Interestingly the test compounds showed only mild ulcerogenic potential when compared to indomethacin