Process for preparing Boc protected amino acid by (Boc) O

The invention discloses a method that uses (Boc) 2 O to make amino acid of Boc protection. It uses acetone and water as solvent, under the existing of (Et 3 N), takes reaction to form amino acid of Boc protection. The invention has high yield, easy to produce and no pollution. The product has good homogeneity, high purity and low cost.