3-(1-Methyl-1,2,3,6-tetrahydropyrid-4-yl)indole.

C14H16N2, Mr = 212.3, orthorhombic, Pca2(1), a = 19.424 (3), b = 6.770 (1), c = 8.899 (1) A, V = 1170.2 (3) A3, Z = 4, Dx = 1.20 g cm-3, Mo K alpha, lambda = 0.71073 A, mu = 0.7 cm-1, F(000) = 456, T = 296 K, final R = 0.043 for 1162 observed reflections. The pi systems in the title compound (1), a serotonin mimic, are in a 'near-planar' conformation (actually twisted 21 degrees from the transoid conformation) as has been postulated to be essential for activity. Molecular-mechanics calculations indicate that the inactive 2-methyl derivative of (1) has near-planar forms of much higher energy in accordance with expectation.