Patent ID: 6028196
Filing Date: 2000-02-22
Classification: A61K,C07K

Abstract:
A process for the preparation of a compound of formula V: ##STR43## which comprises: (1) coupling an amino acid of the formula: ##STR44## with a compound of the formula: ##STR45## in the presence of an acid activating agent which is selected from: DCC and EDC in a solvent which comprises acetonitrile in the presence of HOBT to give a compound of formula I: ##STR46## wherein L is an amino protecting group, followed by: (2) reacting the compound of the formula I with an amino deprotecting agent to give a compound of formula II: ##STR47## followed by: (3) coupling an amino acid of the formula: ##STR48## wherein L is an amino protecting group, with the compound of formula II in the presence of an acid activating agent which is selected from: DCC and EDC in a solvent which comprises acetonitrile in the presence of HOBT, to give a compound of the formula III: ##STR49## wherein L is an amino protecting group, followed by:(4) reacting the compound of the formula III with an amino deprotecting agent to give a compound of the formula IV, or a pharmaceutically acceptable salt thereof: ##STR50## followed by: reacting the compound of the formula IV with methanesulfonic acid to give the compound of formula V.