Bis(4-acetoxy-N,N-dimethyltryptammonium) fumarate: a new crystalline form of psilacetin, an alternative to psilocybin as a psilocin prodrug

The title compound (systematic name: bis{2-[4-(acetyloxy)-1 H -indol-3-yl]ethan-1-aminium} but-2-enedioate), 2C 14 H19 N2 O2 + ·C4 H2 O4 2−, has a single protonated psilacetin cation and one half of a fumarate dianion in the asymmetric unit. There are N-H...O hydrogen bonds between the ammonium H atoms and the fumarate O atoms, as well as N-H...O hydrogen bonds between the indole H atoms and the fumarate O atoms. The hydrogen bonds hold the ions together in infinite one-dimensional chains along [111].