Dimethylamine → tert-Butyl (S)-(1-(dimethylamino)-1-oxo-3-phenylpropan-2-yl)carbamate

Participants

Reaction Conditions

Reaction Steps

To a cooled solution of (S)-2-tert-butoxycarbonylamino-3-phenylpropionic acid (available from Aldrich; 5.3 g, 20 mmol) in dimethylformamide (50 mL) at 0° C. were added 1-hydroxybenzotriazole (available from 3B Scientific Corporation, Libertyville, Ill. 60048, USA; 2.97 g, 22 mmol) and O-benzotriazol-1-yl-N,N,N′,N′-tetramethyluronium hexafluororophosphate (available from Aldrich; 8.30 g, 22 mmol). Diisopropylethylamine (10.7 mL, 61.4 mmol) and dimethylamine in tetrahydrofuran (2M, 15 mL, 30 mmol) were added dropwise. The mixture was stirred for 1 h at 0° C. and ethyl acetate was added. The mixture was washed with water and brine, and dried over sodium sulfate. Evaporation of the solvents gave ((S)-1-dimethylcarbamoyl-2-phenyl-ethyl)-carbamic acid tert-butyl ester as a yellow oil (5.52 g) which was used in the next step without further purification.

Provenance & Evidence