HCID 66704226, compound → HCID 66704245, compound

Participants

Reaction Conditions

Reaction Steps

Acetone (750 g) was added to ethyl 2-benzyloxycarbonylamino-2-carbamoyl-3-[(−)-menthyloxycarbonyl]propionate (150 g, 0.315 mol) and the mixture was heated to 40° C., the solid was dissolved and then the solution was gradually cooled. It was placed to be matured at 10° C. overnight and then stirred at 5° C. for about an hour. The crystals were filtered, washed with sprayed cold acetone (50 ml×2) and dried in airflow at 60° C. to give ethyl (2R)-2-benzyloxycarbonylamino-2-carbamoyl-3-[(−)-menthyloxycarbonyl]propionate (57.9 g). mp. 124° C., yield 38.6%: optical purity (HPLC) 98.8% d.e.

Provenance & Evidence