benzyl 2-carbamoylpyrrolidine-1-carboxylate

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:-10.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Carbamoyl-pyrrolidine-1-carboxylic acid benzyl ester (25.0 g, 101 mmol) was dissolved in pyridine (125 mL) under an N2 atmosphere and cooled to −10° C. The phosphorus oxychloride (12.6 mL, 135 mmol) was dissolved in DCM (25 mL) and added dropwise over 40 mins to the pyridine solution. The reaction mixture's temperature was maintained at −10° C. and the solution was allowed to stir for 2 hours. The reaction was quenched by addition of water/ice (100 g) and transferred into a separatory funnel. The solution was extracted with diethyl ether (3×200 mL). The organic layers were combined and washed with saturated cupric sulfate (200 mL). The organic layer was dried over MgSO4 and concentrated under vacuo to afford 20.0 g (82%) of 2-cyano-pyrrolidine-1-carboxylic acid benzyl ester as a green oil. The reaction mixture's temperature was maintained at −10° C. The reaction was quenched by addition of water/ice (100 g) transferred into a separatory funnel The solution was extracted with diethyl ether (3×200 mL) washed with saturated cupric sulfate (200 mL) The organic layer was dried over MgSO4 concentrated under vacuo

Conditions: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 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. The solution was then cooled to −15° C. while maintaining the temperature below −20° C The reaction mixture was then stirred for 1 hour to return to 0° C 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 concentrated under vacuo