Psilacetin derivatives: Fumarate salts of the methyl-ethyl, methyl-allyl and diallyl variants of the psilocin prodrug

Abstract

The solid-state structures of the salts of three psilacetin derivatives, namely, 4-acetoxy-N-ethyl-N-methyltryptammonium (4-AcO-MET) hydrofumarate {systematic name: [2-(4-acetyloxy-1H-indol-3-yl)ethyl](methyl)ethylazanium 3-carboxyprop-2-enoate}, C15H21N2O2 +·C4H3O4 -, 4-acetoxy-N-allyl-N-methyltryptammonium (4-AcO-MALT) hydrofumarate {systematic name: [2-(4-acetyloxy-1H-indol-3-yl)ethyl](methyl)prop-2-enylazanium 3-carboxyprop-2-enoate}, C16H21N2O2 +·C4H3O4 -, and 4-acetoxy-N,N-diallyltryptammonium (4-AcO-DALT) fumarate-fumaric acid (1/1) (systematic name: bis{[2-(4-acetyloxy-1H-indol-3-yl)ethyl]diprop-2-enylazanium} but-2-enedioate-(E)-butenedioic acid (1/1)), 2C18H23N2O2 +·C4H2O4 2-·C4H4O4, are reported. All three salts possess a protonated tryptammonium cation. The 4-AcO-MET and 4-AcO-MALT compounds are charge-balanced by 3-carboxyacrylate (hydrofumarate) anions. The 4-AcO-DALT complex crystallizes as a two-to-one tryptammonium-to-fumarate salt, which co-crystallizes with a fumaric acid molecule. Each structure is consolidated by N - H⋯O and O - H⋯O hydrogen bonds.