The scope of the reactions of hydrazines and hydrazones. Part 4: Trisubstituted pyrazoles of possible hypoglycemic and antibacterial activity.

Condensation of ethyl 2,4-dioxo-6-phenyl hex-5-enoate (1) with 4-substituted sulphamyl phenylhydrazines (2) led to 1-aryl-3-ethoxycarbonyl-5-styrylpyrazoles (3) which on hydrolysis gave 1-aryl-5-styrylpyrazole-3-carboxylic acids (4) and upon permanganate oxidation gave 1-aryl-3-ethoxycarbonylpyrazole-5-carboxylic acids (5). Similar condensation of hydralazine (6) with (1) gave the corresponding pyrazole (7) which on hydrolysis gave the acid 8.