Chloromethyl pivalate → 1-[(2R,3R)-2-(2,4-difluorophenyl)-2-hydroxy-3-[2-oxo-3-[4-(1H-tetrazol-1-yl)phenyl]-1-imidazolidinyl]butyl]-4-[(2,2-dimethylpropanoyloxy)methyl]-1H-1,2,4-triazolium chloride

Participants

Reaction Steps

To a mixture of 1-[(1R,2R)-2-(2,4-difluorophenyl)-2-hydroxy-1-methyl-3-(1H-1,2,4-triazol-1-yl)propyl]-3-[4-(1H-tetrazol-1-yl)phenyl]-2-imidazolidinone (0.48 g) and acetone (10 ml) was added chloromethyl pivalate (2.9 ml), and the mixture was stirred under reflux. After 88 hours, chloromethyl pivalate (1.45 ml) was added to the mixture. The mixture was further stirred for 14 hours under reflux. The reaction mixture was concentrated under reduced pressure. To the residue was added diethyl ether (8 ml), and the resulting powder was collected by filtration. The powder was subjected to ODS column chromatography (eluent: methanol/water=3/2) to give 1-[(2R,3R)-2-(2,4-difluorophenyl)-2-hydroxy-3-[2-oxo-3-[4-(1H-tetrazol-1-yl)phenyl]-1-imidazolidinyl]butyl]-4-[(2,2-dimethylpropanoyloxy)methyl]-1H-1,2,4-triazolium chloride (Compound 2, 0.25 g) as a white powder.

Provenance & Evidence