Hydrochloric Acid → Treprostinil

Participants

Reaction Steps

A 250-mL, round-bottom flask equipped with magnetic stirrer was charged with treprostinil diethanolamine salt (4 g) and water (40 mL). The mixture was stirred to obtain a clear solution. To the clear solution, ethyl acetate (100 mL) was added. While stirring, 3M HCl (3.2 mL) was added slowly until pH ˜1 was attained. The mixture was stirred for 10 minutes and organic layer was separated. The aqueous layer was extracted with ethyl acetate (2×100 mL). The combined organic layers was washed with water (2×100 mL), brine (1×50 mL) and dried over anhydrous Na2SO4. The ethyl acetate solution of treprostinil was filtered and the filtrate was concentrated under vacuum at 50° C. to give off-white solid. The crude treprostinil was recrystallized from 50% ethanol in water (70 mL). The pure treprostinil was collected in a Buchner funnel by filtration and cake was washed with cold 20% ethanolic solution in water. The cake of treprostinil was air-dried overnight and further dried in a vacuum oven at 50° C. under high vacuum to afford 2.9 g of treprostinil (Yield 91.4%, purity (HPLC, AUC, 99.8%).

Provenance & Evidence