4-Methylmorpholine → Benzyl 2-carbamoylpyrrolidine-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

Pyrrolidine-1,2-dicarboxylic acid 1-benzyl ester (30.0 g, 121 mmol) was dissolved in DCM (180 mL). The solution was cooled to 0° C. and N-methyl-morpholine (12.8 g, 127 mmol) was added over a period of 10 mins. The solution was then cooled to −15° C. and the ethyl chloroformate (13.7 g, 126 mmol) in DCM (30 mL) was added dropwise. The solution was then stirred for 2 hours at −25° C. Next, the solution was placed under NH3 (g) while maintaining the temperature below −20° C. The reaction mixture was then stirred for 1 hour while allowing the temperature to return to 0° C. The solution was poured in H2O (120 mL) and the organic layer was partitioned from the aqueous layer. The organic layer was then washed with 1N HCl (2×50 mL), 1N NaHCO3 (2×50 mL), dried over MgSO4 and concentrated under vacuo to afford 27.8 g (88%) of 2-carbamoyl-pyrrolidine-1-carboxylic acid benzyl ester, as a colorless oil.

Provenance & Evidence