Triethylamine → (N-benzyloxycarbonyl-N-methyl-O-benzyl-L-tyrosyl)-D-alanine methyl ester

Participants

Reaction Conditions

Reaction Steps

A solution of isobutyl chloroformate (2.00 g.) in acetone (10 ml.) was added dropwise to a solution of N-benzyloxycarbonyl-N-methyl-O-benzyl-L-tyrosine (6.0 g.) and triethylamine (1.45 g.) in acetone (60 ml.) with stirring and cooling to -10° C. A solution of D-alanine methyl ester (2.22 g.) and triethylamine (1.45 g.) in chloroform (30 ml.) was then added. Stirring was continued for one hour at -10° C., then overnight at room temperature. The mixture was stripped of solvents. Water and ethyl acetate were added to the residue. The ethyl acetate layer was washed with water, saturated aqueous sodium bicarbonate, water again, aqueous citric acid, water again and saturated aqueous sodium chloride, dried over magnesium sulfate, filtered and stripped of ethyl acetate, affording (N-benzyloxycarbonyl-N-methyl-O-benzyl-L-tyrosyl)-D-alanine methyl ester (97% yield).

Provenance & Evidence