Hydrochloric Acid → Focalin

Participants

Reaction Conditions

Reaction Steps

The organic layer was dewatered by azeotropic distillation under vacuum and was concentrated in vacuum to give D-threo-methylphenidate free base as an oil, which was used directly in hydrochloride salt formation. The solution of D-threo-methylphenidate free base in isopropanol (0.29 Kg) was charged to a jacketed vessel, cooled to 5-10° C. and treated with a solution of 37% HCl (78 g) in a mixture of isopropanol (40 g) and methanol (63 g) at less than 20° C. The formed slurry was cooled to 0 to 5° C., aged for 2 hours and filtered. The wet cake was washed with isopropanol (0.32 Kg total) in two portions and dried under vacuum at 45° C. for 16 hours to give Dexmethylphenidate hydrochloride (0.175 Kg, 0.649 mol, 86% yield) as a off-white solid; mp 206.4° C., ee 99.7%, α25D +83° (c 1 wt %, MeOH).

Provenance & Evidence