Water → 2-{(S)-2-[4-(4-methoxy-3-methyl-phenyl)-2,5-dioxo-imidazolidin-1-yl]-3-phenyl-propionylamino}-thiazole-4-carboxylic acid methyl ester

Participants

Reaction Conditions

Reaction Steps

A solution of 2-{(S)-2-[2-amino-2-(4-methoxy-3-methyl-phenyl)-acetylamino]-3-phenyl-propionylamino}-thiazole-4-carboxylic acid methyl ester (0.40 g , 0.83 mmol) and diisopropylethylamine (0.72 mL, 4.14 mmol) in dichloromethane (20 mL) was added to a solution of diphosgene (0.07 mL, 0.58 mmol) in dichloromethane (20 mL) at −10° C. The mixture was stirred at −10° C. for 0.5 hours. Water was added to quench the reaction, then the mixture was extracted with ethyl acetate. The organic layer was separated, washed with water, brine, dried over sodium sulfate and concentrated. The residue was purified by chromatography over silica gel eluted with ethyl acetate to give 2-{(S)-2-[4-(4-methoxy-3-methyl-phenyl)-2,5-dioxo-imidazolidin-1-yl]-3-phenyl-propionylamino}-thiazole-4-carboxylic acid methyl ester as an off white foam (0.29 g, 69%).

Provenance & Evidence