Patent ID: 7049399

Claim:
A process for the preparation of polypeptide 1, or a pharmaceutically acceptable salt thereof, comprising L-alanine, L-glutamic acid, L-lysine and L-tyrosine randomly arranged in the polypeptide 1, wherein said process comprises the steps of: (a) polymerization of a mixture of the N-carboxyanhydrides of L-alanine, L-tyrosine, protected L-glutamate, and protected L-lysine, to obtain protected copolymer 6 or a salt thereof; (b) deprotection of the protected copolymer 6 or a salt thereof to afford polypeptide 1 or a pharmaceutically acceptable salt thereof in a single step; (c) separation and purification of the polypeptide 1 or a pharmaceutically acceptable salt thereof.