Hydrochloric Acid → Bimatoprost Acid

Participants

Reaction Steps

A solution of (6Z,8aR,9R,10R,11aS)-4,5,8,8a,9,10,11,11a-octahydro-10-hydroxy-9-((S,E)-3-hydroxy-5-phenylpent-1-enyl)cyclopenta[b]oxecin-2(3H)-one (2 g, 5.4 mmol) in 20 ml 2-propanol and 6.3 ml of 3 N potassium hydroxide aqueous solution in 50 mL round-bottom flask was refluxed and stirred for 2 hours. The mixture was cooled to room temperature and adjusted to a pH of 8.5 with 3 N hydrochloric acid aqueous solution. Subsequently, the 2-propanol was removed under reduced pressure and resulting mixture was diluted with 30 ml saturated NaHCO3 aqueous solution. The basic aqueous solution was extracted with 30 ml ethyl acetate twice and the aqueous layer was adjusted to a pH of 3 with 3 N hydrochloric acid aqueous solution. Then, the acidic aqueous layer was extracted with 50 ml ethyl acetate. The organic layer was dried over anhydrous MgSO4, the solid was filtered off and organic solvent was evaporated off under vacuum to obtain 2 g of the crude title compound.

Provenance & Evidence