(R)-8-Chloro-1-methyl-2,3,4,5-tetrahydro-1H-3-benzazepine orotate salt hydrate was prepared by addition of one equivalent of orotic acid to a solution of (R)-8-chloro-1-methyl-2,3,4,5-tetrahydro-1H-3-benzazepine in acetonitrile or isopropanol at 60° C. Orotic acid, at 60° C., was added drop-wise, in the corresponding solvent, with vigorous stirring. Precipitation occurred immediately and the suspension was allowed to cool and stir overnight. Compound 1 orotate salt hydrate prepared in isopropanol consisted of a mixture of the anhydrous and hydrated forms which was converted to the hydrated form by slurring in isopropanol for two days. Alternatively, (R)-8-Chloro-1-methyl-2,3,4,5-tetrahydro-1H-3-benzazepine orotate salt hydrate was prepared by slurrying anhydrous (R)-8-chloro-1-methyl-2,3,4,5-tetrahydro-1H-3-benzazepine orotate salt in water. (R)-8-Chloro-1-methyl-2,3,4,5-tetrahydro-1H-3-benzazepine orotate salt hydrate had an extrapolated melt/recrystallization onset temperature by DSC of 173° C.
