Synthesis of 1-alkyl(aralkyl)-4-acyl-2-piperazinones (original) (raw)

piperazinones are formed in high yields during selective acy!ation of N-monosubstituted ethylenediamines by benzoyl and cyclohexylcarbonyl chlorides in the presence of pyridine hydrochloride and treatment of the reaction products with chloroacetyl chloride in the presence of potassium tert-butylate. Among 2-piperazinones, having different biological activities [1-3], the little investigated 4-acyl derivatives are of special interest, since the 4-acyl-2-piperazinone fragment is included in the structure of a new anthelmintic prasiquantel (I) [4] with a broad spectrum of activity. The aim of the present work was to find suitable method for the synthesis of l-alkyl(aralkyl)-4-acyl-2-piperazinones (IIa-g). Compounds IIa-g were selected as the object products, since they contain the same functional groups as prasiquantel, and have a similar lyophilicity. In the course of the investigation~ we studied schemes of synthesis of compound IIa-g, based on the use of available N-monosubstituted ethylenediamines IIIa-c.