Syntheses of N-substituted 2(3,4)-pyridylcarboxylic acid hydrazides with analgesic and antiinflammatory activity.

A group of N-substituted 2(3,4)-pyridylcarboxylic acid hydrazides were synthesized to investigate the effects that changes in functionality on the terminal hydrazide nitrogen have on analgesic and antiinflammatory activities. The most active analgesic-antiinflammatory compound was 1-(2-pyridylcarbonyl)-2-(2-pyridyl)hydrazine (10a), which was much more potent than dextropropoxyphene and caused a 100% inhibition of carrageenan-induced paw edema up to 5 h. Pyridylcarbonylhydrazides 5a, 8, and 10c exhibited analgesic activity similar to dextropropoxyphene. Although 10b was an inactive analgesic agent, it exhibited antiinflammatory activity similar to 10a.