Cyanomethylenetributylphosphorane → methyl 2-((3R,5R,6S)-5-(3-chlorophenyl)-6-(4-chlorophenyl)-1-((S)-1-(N,1-dimethylcyclopropanesulfonamido)butan-2-yl)-3-methyl-2-oxopiperidin-3-yl)acetate

Participants

Reaction Steps

A solution of methyl 2-((3R,5R,6S)-5-(3-chlorophenyl)-6-(4-chlorophenyl)-3-methyl-1-((S)-1-(1-methylcyclopropanesulfonamido)butan-2-yl)-2-oxopiperidin-3-yl)acetate (21.7 mg, 0.036 mmol; Example 193), 2-(tributylphosphoranylidene)acetonitrile (8.8 mg, 0.036 mmol) and one drop of MeOH in toluene (0.5 mL) was stirred at 110° C. for 1 h. Flash column purification on silica gel (0 to 60% EtOAc in hexanes) gave methyl 2-((3R,5R,6S)-5-(3-chlorophenyl)-6-(4-chlorophenyl)-1-((S)-1-(N,1-dimethylcyclopropanesulfonamido)butan-2-yl)-3-methyl-2-oxopiperidin-3-yl)acetate. This was hydrolyzed with LiOH (1N solution in water, 0.3 mL) in ethanol (0.5 mL) for 3 h at rt. HPLC purification (C18 column, eluted with 10 to 95% CH3CN in water, with 0.1% TFA) gave the title compound.

Provenance & Evidence