7-Methyl-5,6,7,8-tetrahydro-1-benzothieno[2,3-d]pyrimidin-4-amine

Abstract

In the title compound, C11H13N3S, two of the C atoms of the cyclohexene ring and the methyl group attached to it are disordered over two sets of sites in a 0.544 (2):0.456 (2) ratio. The benzothiene and pyrimidine rings are almost coplanar with an angular tilt of 2.371 (9)° between them. The thiophene ring is essentially planar (r.m.s. deviation 0.05 Å), while the cyclohexene ring in both the major- and minor-occupancy conformers adopts a half-chair conformation. In the crystal structure, pairs of intermolecular N—H...N hydrogen bonds involving the amino groups result in centrosymmetric head-to-head dimers about inversion centres, corresponding to an R22(8) graph-set motif. Further, N—H...N hydrogen bonding generates a two-dimensional hydrogen-bonded network perpendicular to the ac plane and running along the diagonal of the ac plane.