Norpsilocin: freebase and fumarate salt

Abstract

The solid-state structures of the naturally occurring psychoactive tryptamine norpsilocin {4-hy-droxy-N-methyl-tryptamine (4-HO-NMT); systematic name: 3-[2-(methyl-amino)-eth-yl]-1H-indol-4-ol}, C₁₁H₁₄N₂O, and its fumarate salt (4-hy-droxy-N-methyl-tryptammonium fumarate; systematic name: bis-{[2-(4-hy-droxy-1H-indol-3-yl)eth-yl]methyl-aza-nium} but-2-enedioate), C₁₁H₁₅N₂O⁺·0.5C₄H₂O₄ ^2-, are reported. The freebase of 4-HO-NMT has a single mol-ecule 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 ethyl-amine 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; hydrogen bonding; indoles; tryptamines.

Figure 1

The mol­ecular structure of 4-hy­droxy-N-methyl­tryptamine, showing the atom labeling. Displacement ellipsoids are drawn at the 50% probability level. Dashed bonds indicate the minor occupancy disordered component in the structure.

Figure 2

The mol­ecular structure of bis­(4-hy­droxy-N-methyl­tryptammonium)­fumarate, showing the atom labeling. Displacement ellipsoids are drawn at the 50% probability level. Hydrogen bonds are shown as dashed lines. Symmetry code: (i) 1 − x, −y, 2 − z.

Figure 3

The hydrogen bonding (Table 2 ▸) of a fumarate ion in the structure of bis­(4-hy­droxy-N-methyl­tryptammonium)­fumarate, with hydrogen bonds shown as dashed lines. Displacement ellipsoids are drawn at the 50% probability level. Hydrogen atoms not involved in hydrogen bonding are omitted for clarity. Symmetry codes: (i) 1 − x, −y, 2 − z; (ii) 2 − x, 1 − y, 2 − z; (iii) 1 − x, −y, 1 − z; (iv) 2 − x, −y, 2 − z; (v) x, y, 1 + z; (vi) −1 + x, y, z; (vii) −1 + x, −1 + y, z.

Figure 4

The crystal packing of (a) 4-HO-NMT, and of (b) bis­(4-HO-NMT) fumarate, both shown along the a axis. The hydrogen bonds (Tables 1 ▸ and 2 ▸) are shown as dashed lines. Displacement ellipsoids are drawn at the 50% probability level. Hydrogen atoms not involved in hydrogen bonding are omitted for clarity. For (a) only one component of the disorder is shown.