DRYING OF N-CARBOBENZOXY AMINO ACID

摘要

PROBLEM TO BE SOLVED: To provide a method for suitably drying an N-carbobenzoxy amino acid having a protectedα-amino group without melting and solidifying by subjecting the wet N-carbobenzoxy amino acid separated from an aqueous solvent to drying at the drying temperature not higher than the melting point of the wet crystalline. SOLUTION: An N-carbobenzoxy amino acid having a protectedα-amino group is dried without melting and solidifying by filtering a slurry solution containing the crystals of an N-carbobenzoxy amino acid (e.g. N-carbobenzoxy-S- phenyl-L-cysteine) to obtain the wet N-carbobenzoxy amino acid and heating and drying the wet N-carbobenzoxy amino acid separated from the aqueous solvent at a drying temperature not higher than the melting point of the wet crystal under a reduced pressure in the method for drying an N-carbobenzoxy amino acid.