Patent ID: 8481737

Claim:
A process for preparing the Form A of a crystalline citrate salt of (S)-4-(4-Chloro-phenyl)-1-{3-[7-(1-hydroxy -1-methyl-ethyl)-11H-10-oxa-1-aza-dibenzo [a,d]cyclohepten-5-ylidene]-propyl}-3,3-dimethyl-piperidin-4-ol, comprising: a) combining citric acid with a solution of (S)-4-(4-Chloro-phenyl)-1-{3-[7-(1-hydroxy-1-methyl-ethyl)-11H-10-oxa-1-aza-dibenzo[a,d]cyclohepten-5-ylidene]propyl}-3,3-dimethyl-piperidin-4-ol in acetone to precipitate the crystalline citrate salt; and b) isolating the crystalline citrate salt.