2,6-Dichlorobenzoyl chloride → (S)-2-tert-butoxycarbonylamino-3-[4-(2,6-dichlorobenzoylamino)phenyl]propionic acid methyl ester

Participants

Reaction Steps

To a solution of 4-amino-N-[(1,1-dimethylethoxyl)carbonyl]-L-phenylalanine methyl ester 2.6 g, 8.6 mmol) in dichloromethane (20 mL) were added diisopropylethylamine (2.3 mL, 13 mmol) followed by 2,6-dichlorobenzoyl chloride (1.99 g, 9.5 mmol) at room temperature. The mixture was stirred for 15 hr at which time a white precipitate formed. The mixture was diluted with 30 mL of dichloromethane and 50 mL of water. The layers were separated and the aqueous layer was extracted with dichloromethane (2×50 mL). The combined extracts were washed with brine and dried over anhydrous magnesium sulfate. Filtration and concentration of the solvent gave 4.03 g (quant) of 4-[(2,6-dichlorophenylcarbonyl)amino]-N-[(1,1-dimethylethoxyl)carbonyl]-L-phenylalanine methyl ester as a white solid: mp 148-151° C.

Provenance & Evidence