Hydrochloric Acid → 4-Acetylamino-2-methyl-5-phenyl-3-pentanone

Participants

Reaction Steps

A solution of 2.30 g of N-acetylphenylalanine methyl ester (10.40 mmol) in 15 ml of tetrahydrofuran is chilled at -60° C. with a dry ice/acetone bath. To the mixture is added dropwise 10.40 ml of 2M solution of isopropylmagnesium chloride in tetrahydrofuran (20.8 mmol) with stirring and the mixture allowed to stand for 15 minutes and returned to room temperature. The mixture was stirred for 3 hours. To the mixture is added saturated aqueous ammonium chloride under ice cooling, followed by the addition of 5% hydrochloric acid and the mixture is extracted with ethyl acetate. The extract is washed with saturated brine, dried over sodium sulfate, filtered and the filtrate concentrated in vacuo. The resulting crude product is chromatographed on a column of silica gel, eluting with methylene chloride and ethyl acetate (4:1) to give 1.40 g of the objective 4-acetylamino-2-methyl-5-phenyl-3-pentanone 5. Yield, 57.7%.

Provenance & Evidence