This paper reports the synthesis of the new compound 1-[2-acetoxy-3-(4-phenyl-1-piperazinyl)propyl]pyrrolidin-2-one (Ac-MG-1). Preliminary pharmacological assessment revealed that Ac-MG-1 possesses anti-arrhythmic activity and a local anesthetic effect. The crystal structure of Ac-MG-1 was determined by X-ray diffraction, and conformational analysis was performed both for Ac-MG-1 and for other derivatives of (arylpiperazinyl)propylpyrrolidin-2-one.