Benzyl chloroformate → HCID 13605332, compound

Participants

Reaction Steps

A mixture of 67 ml of 2.5N aqueous sodium hydroxide and 5.3 g of S-(2-nitro-4-trifluoromethylphenyl)-L-cysteine obtained in Reference Example 10 is stirred at room temperature for 30 minutes. Two point seven ml of benzyloxycarbonyl chloride and 19 ml of 1N aqueous sodium hydroxide are simultaneously added dropwise to the mixture at ice bath temperature over a period of 30 minutes. The resulting mixture is stirred at room temperature for further 2.5 hours and extracted with ethyl ether. The aqueous layer is acidified slightly with 1N hydrochloric acid and extracted with ethyl acetate. The extract is dried over anhydrous magnesium sulfate and concentrated under reduced pressure. The residue is crystallized from ethyl ether to yield 5.5 g of S-(2-nitro-4-trifluoromethylphenyl)-N-benzyloxycarbonyl-L-cysteine as pale yellow crystals, m.p. 150°-153° C.

Provenance & Evidence