Novel pseudopolymorph of the active metabolite of perindopril

Abstract

The dimethyl sulfoxide hemisolvate of perindoprilat [systematic name: (1S)-2-((S)-{1-[(2S,3aS,7aS)-2-carboxyoctahydro-1H-indol-1-yl]-1-oxopropan-2-yl}azaniumyl)pentanoate dimethyl sulfoxide hemisolvate], C17H28N2O5·0.5C2H6OS, an active metabolite of perindopril, has been synthesized, structurally characterized by single-crystal X-ray diffraction and compared with its ethanol disolvate analogue [Pascardet al.(1991).J. Med. Chem.34, 663–669]. Both compounds crystallize in the orthorhombicP212121space group in the same zwitterionic form, with a protonated alanine N atom and an anionic carboxylate group at then-alkyl chain. The three structural units present in the unit cell (two zwitterions and the solvent molecule) are held together by a rich system of O—H...O, N—H...O and C—H...O hydrogen-bond contacts.