DMT analogues: N-ethyl-N-propyl­tryptamine and N-allyl-N-methytryptamine as their hydro­fumarate salts

The solid-state structures of the hydro­fumarate salts of two N,N-di­alkyl­tryptamines, namely N-ethyl-N-propyl­tryptammonium (EPT) hydro­fumarate {systematic name: [2-(1H-indol-3-yl)eth­yl](meth­yl)propyl­aza­nium 3-carb­oxy­prop-2-enoate}, C(15)H(23)N(2) (+)·C(4)H(3)O(4) (−), and N-allyl-N-methyl­tryptammonium (MALT) hydro­fumarate {systematic name: [2-(1H-indol-3-yl)eth­yl](meth­yl)(prop-2-en-1-yl)aza­nium 3-carb­oxy­prop-2-enoate}, C(14)H(19)N(2) (+)·C(4)H(3)O(4) (−), are reported. Both compounds possess a protonated tryptammonium cation, and a hydro­fumarate anion in the asymmetric unit. The ethyl group of the EPT cation is modeled as a two-component disorder with 50% occupancy for each component. In the extended structure, N—H⋯O and O—H⋯O hydrogen bonds generate infinite two-dimensional networks parallel to the (001) plane for both compounds.