Synthesis and Biological Activity of 5-aryl-4-acyl-3-hydroxy-1-(2-piperazin-1-ylethyl)-2,5-dihydropyrrol-2-ones and their Derivatives

5-Aryl-4-acyl-3-hydroxy-1-(2-piperazin-1-ylethyl)-2,5-dihydropyrrol-2-ones (I) were synthesized by reactions of acylpyruvate methyl esters with a mixture of aromatic aldehyde and 2-(1-piperazino)-1-ethylamine. Then, the corresponding hydrochlorides (II) were obtained. Compounds I were transformed into 3,4-diaryl-4,6-dihydro-5-(2-piperazin-1-ylethyl)pyrrolo[3,4-c]pyrazol-6-ones (III) by reaction with hydrazine hydrate. The antimicrobial activity of compounds I and the influence of compounds II and III on blood coagulation were studied. The acute toxicity of two compounds was evaluated.