4-Chlorobutyl carbonochloridate → 4-Chlorobutyl (2R,3R)-3-[(2Z)-7-(Ethylamino)-7-oxohept-2-en-1-yl]-4-hydroxy-2-[(1E,3S)-3-hydroxy-5-phenylpent-1-en-1-yl]cyclopentyl Carbonate

Participants

Reaction Steps

To a solution of bimatoprost (Cayman Chemicals 16820, Lot 188757; 123 mg, 0.30 mmol) in DCM (3 mL) at 0° C. was added DMAP (39 mg, 0.31 mmol) followed by the slow addition of 4-chlorobutyl chloroformate (43 uL, 0.31 mmol). After 3 days at ambient temperature, the mixture was diluted with DCM and washed with water (1×) and brine (1×). The DCM layer was dried over anhydrous sodium sulfate and concentrated under reduced pressure. The crude mixture of regioisomers and diacylated products was submitted to column chromatography (ethyl acetate-hexane 25-100%, followed by methanol-dichloromethane (5-15%) to provide as the major component isolated, 11-acylated chloride g-1 (25 mg, 15%) as a colorless oil.

Provenance & Evidence