Dichloromethane → Diisopropylethylamine

Participants

Reaction Steps

To a solution of N-boc-morpholine-3-carboxylic acid (2 g, 9.379 mmol) in 60 mL of dichloromethane and was added TBTU (3.313 g, 10.32 mmol) and diisopropylethyl amine (1.96 mL, 11.25 mmol). The reaction was stirred for 30 min. In the meantime, a solution of D-alanine methyl ester hydrochloride (1.93 g, 18.76 mmol) and diisopropylethylamine (3.27 mL, 18.76 mmol) in 20 mL of dichloromethane was prepared and finally added to the reaction mixture. The reaction was left stirring at room temperature for 2 h. UPLC-MS analysis showed the expected product (peak at 0.60 min, m/z=317 (M+1), 261 (M−t-Bu+1), 217 (M−Boc+1)). The reaction was diluted with dichloromethane and extracted with sat. NaHCO3, dried (Na2SO4), and the solvent removed. The crude (5.56 g) was taken to the next step without further purification.

Provenance & Evidence