Síntese e hidrólise de azalactonas de erlenmeyer-plöchl mediadas por radiação micro-ondas em aparelhos doméstico e dedicado: Experimentos de química orgânica para a graduação

Abstract

This work describes a green chemistry experiment for the synthesis of Erlenmeyer-Plöchl azalactones mediated by microwave irradiation, employing both dedicated and domestic equipment. Hippuric acid was reacted with equimolar amounts of benzaldehyde, p-chloro-benzaldehyde or p-A,V-dimethyl-benzaldehyde in acetic anhydride as the solvent. Acid hydrolysis of obtained 4-benzylidene-2-phenyloxazol-5(4H)-one under microwave and convectional heating afforded Z-(benzoylamino)cinnamic acid at a 51-61.5% yield. The UV-Vis molecular spectra of 4-benzylidene-2-phenyloxazol-5(4H)-one and 4-(4'-A,V- dimethylbenzylidene)-2-phenyloxazol-5(4H)-one were obtained in ethanol, CH 2Cl2 and DMSO and bathochromic shift was observed for the latter azalactone.