Studies on some B-aroyl- [4 [1,3-disubstituted-2-pyrazolin-5-one]] propionic acids

Baroylarcylic acids [I] react with 1, 3-disubstituted-2-pyrazolin-5-ones in dry benzene to give the adducts II. Estrification of lid with diazomethane gives the corresponding methyl ester [III]. Reactions of II with hydrazine hydrate and phenylhydrazine afford the corresponding pyridazinones [V and VI]. Dehydration of II yield the butenolides [VII]. The reactions of pyrida-zinones V with anisaldehyde, ethyl bromoacetate, diethyl sulfate and Grignard reagents are also described. The in vitro antibacterial screening reveals substantial activities against Gram-positive and Gram-negative bacteria for compounds lie and lid; while compounds IIa, IIb and Vb are inactive