Benzyl chloroformate → HCID 86597993, compound

Participants

Reaction Conditions

Reaction Steps

In 38.8 g of ethyl acetate was dissolved 15.6 g (78.0 mmol) of the mixture of the enantiomers obtained in Reference Example 1. To the resulting solution were added 38.8 g of water and 15.5 g of potassium bicarbonate and mixed. To this solution cooled to 0° C. was dropped 15.0 g of benzyloxycarbonyl chloride over 1 hour. After the completion of dropping, the solution was raised to room temperature, and then agitated at room temperature for 4 hours to complete the reaction. After the completion of reaction, to the reaction mixture was added 40 g of ethyl acetate to separate the resultant solution. From the resulting organic phase the solvent was removed by distillation to obtain an oily mixture of ethyl (2S, 3aS, 7aS)-N-benzyloxycarbonyl-octahydro-1H-indole-2-carboxylate and ethyl (2R, 3aR, 7aR)-N-benzyloxy-carbonyl-octahydro-1H-indole-2-carboxylate. This oily mixture was purified using n-hexane/ethyl acetate (eluate of the volume ratio of 85:15) by silica gel column chromatography to yield 24.3 g of a mixture of ethyl (2S, 3aS, 7aS)-N-benzyloxycarbonyl-octahydro-1H-indole-2-carboxylate and ethyl (2R, 3aR, 7aR)-N-benzyloxycarbonyl-octahydro-1H-indole-2-carboxylate [contained pure compounds were 22.8 g, 68.8 mmol (yield 88.2%)].

Provenance & Evidence