Methyl iodide → Bimatoprost acid methyl ester

Participants

Reaction Conditions

Reaction Steps

A solution of (5Z)-7-((1R,2R,3R,5S)-3,5-dihydroxy-2-((S,E)-3-hydroxy-5-phenylpent-1-enyl)cyclopentyl)hept-5-enoic acid (2 g from Example 53) was dissolved in 20 ml N,N-dimethylformamide in 50 mL round-bottom flask, followed by addition of potassium carbonate (2.2 g, 16.2 mmol) and iodomethane (1.1 g, 8.1 mmol). The reaction mixture was heated to 40° C. and stirred for 2 hours. The mixture was cooled to room temperature and the solid was filtered off. The filtrate was subsequently diluted and extracted with 20 ml ethyl acetate and 20 ml water. The mixture was phase separated and the organic layer was dried over anhydrous MgSO4, the solid was filtered off and organic solvent was evaporated off under vacuum. The crude product was purified by chromatography on silica gel using a mixture of hexane and ethyl acetate as a gradient eluent. Yield of the title compound was 1.6 g (73.5% in 2 steps)

Provenance & Evidence