Norpsilocin: freebase and fumarate salt

Abstract

The solid-state structures of the naturally occurring psychoactive tryptamine norpsilocin {4-hydroxy-N-methyltryptamine (4-HO-NMT); systematic name: 3-[2-(methylamino)ethyl]-1H-indol-4-ol}, C11H14N2O, and its fumarate salt (4-hydroxy-N-methyltryptammonium fumarate; systematic name: bis{[2-(4-hydroxy-1H-indol-3-yl)ethyl]methylazanium} but-2-enedioate), C11H15N2O+·0.5C4H2O42−, are reported. The freebase of 4-HO-NMT has a single molecule in the asymmetric unit joined together by N—H...O and O—H...O hydrogen bonds in a two-dimensional network parallel to the (100) plane. The ethylamine arm of the tryptamine is modeled as a two-component disorder with a 0.895 (3) to 0.105 (3) occupancy ratio. The fumarate salt of 4-HO-NMT crystallizes with a tryptammonium cation and one half of a fumarate dianion in the asymmetric unit. The ions are joined together by N—H...O and O—H...O hydrogen bonds to form a three-dimensional framework, as well as π–π stacking between the six-membered rings of inversion-related indoles (symmetry operation: 2 − x, 1 − y, 2 – z).

Keywords

• crystal structure
• tryptamines
• indoles
• hydrogen bonding