Diphosgene → (2S,3S)-N-(4-acetyl-thiazol-2-yl)-2-[(R)-4-(4-methoxy-phenyl)-2,5-dioxo-imidazolidin-1-yl]-3-phenyl-butyramide

Temperature

0 °C

(2S,3S)-N-(4-Acetyl-thiazol-2-yl)-2-[(R)-2-amino-2-(4-methoxy-phenyl)-acetylamino]-3-phenyl-butyramide (2.7 g, 90% purity, 5.2 mmol) and diisopropylethylamine (4.2 mL, 23.6 mmol) in tetrahydrofuran (50 mL) were added to a solution of diphosgene (0.48 mL, 4 mmol) in a mixture of toluene (50 mL) and tetrahydrofuran (50 mL) over 10 minutes at 0° C. The mixture was stirred at 0° C. for 20 minutes and diluted with ethyl acetate. The mixture was washed with water, brine and dried (sodium sulfate). Evaporation of the solvents and chromatography of the residue over silica gel with 0.4-1% v/v methanol in dichloromethane gave (2S,3S)-N-(4-acetyl-thiazol-2-yl)-2-[(R)-4-(4-methoxy-phenyl)-2,5-dioxo-imidazolidin-1-yl]-3-phenyl-butyramide (2.36 g, 92%) as a white solid.

1. washThe mixture was washed with water, brine
2. dry with materialdried (sodium sulfate)
3. customEvaporation of the solvents and chromatography of the residue over silica gel with 0.4-1% v/v methanol in dichloromethane

ORD record

ord-269506ebc9e54b1dac5e31a8e9d82d6e

Source dataset

uspto-grants-2008_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07427635B2