N -Methyl-serotonin hydrogen oxalate.

The solid-state structure of N -methyl-serotonin {systematic name: [2-(5-hy-droxy-1 H -indol-3-yl)eth-yl](meth-yl)aza-nium hydrogen oxalate}, C 11 H 15 N 2 O + ·C 2 HO 4 - , is reported. The structure possesses a singly protonated N -methylserotonin cation and one hydrogen oxalate anion in the asymmetric unit. In the crystal, the mol-ecules are linked by N-H⋯O and O-H⋯O hydrogen bonds into a three-dimensional network.