Convenient synthesis and biological activity of 4-Aminomethylene 1-Phenylpyrazolidine-3,5-diones

Abstract

Reaction of (Z)-4-((dimethylamino)methylene)-1-phenylpyrazolidine-3,5-dione (1) with different nucleophiles is described. Treatment of enaminone 1 with phenylhydrazine led to 3-oxo-N’,2-diphenyl-2,3-dihydro-1H-pyrazole-4-carbohydrazide 7. New enaminone derivatives 2–6 and 12–14 were conveniently obtained in high yields via nucleophilic substitution of the dimethylamino group in enaminone 1 when reacted with o-aminophenol, o-aminothiophenol, ethanolamine, cysteamine hydrochloride, piperidine, morpholine, 2-aminopyridine and glycine. Reaction of enaminone 1 with diaza-nucleophiles, such as hydrazine hydrate, ethylenediamine and o-phenylenediamine, afforded the corresponding bis-enaminones 9–11. Anti-inflammatory and antimicrobial activities of some new products were evaluated. Compounds 1, 2, 4, 7, 12a, and 12b showed high anti-inflammatory activity compared with indomethacin as the reference, while the highest antimicrobial effect was observed in the case of compound 3.