Lamotrigine ethanol monosolvate

Lamotrigine is an active pharmaceutical ingredient used as a treatment for epilepsy and psychiatric disorders. Single crystals of an ethanolate solvate, C₉ H₇ Cl₂ N 5·C₂ H₅ OH, were produced by slow evaporation of a saturated solution from anhydrous ethanol. Within the crystal structure, the lamotrigine molecules form dimers through N - H...N hydrogen bonds involving the amine N atoms in the ortho position of the triazine group. These dimers are linked into a tape motif through hydrogen bonds involving the amine N atoms in the para position. The ethanol and lamotrigine are present in a 1:1 ratio in the lattice with the ethyl group of the ethanol molecule exhibiting disorder with an occupancy ratio of 0.516 (14):0.484 (14).