Hydrochloric Acid → Olopatadine Hydrochloride

Participants

Reaction Conditions

Reaction Steps

To a suspension of the olopatadine (free base) produced in step b. (42.40 g, 0.123 mol; HPLC assay: 97.71%) in acetone (601 g) was added concentrated hydrochloric acid (15.39 g, 0.135 mol; assay: 32%). The white suspension was stirred 15 hours at 20-25° C. After the filtration, the white solid washed with acetone (72.5 g) and dried under vacuum for 14 hours at 60° C. to give an off white powdery olopatadine hydrochloride (yield: 44.35 g, 0.119 mol; assay: 100% (HPLC), HPLC purity: 99.96%, Z/E-Isomers: 99.97/0.03, yield: 96.7%, polymorphic form A). Overall yield for olopatadine hydrochloride based on Olo-IM2: 49.7%. Calculated volume yield for the synthesis of Olopatadine-HCl: 5.0%

Provenance & Evidence