Patent ID: 6046333
Filing Date: 2000-04-04
Classification: C07D

Abstract:
A process for the preparation of a compound of formula IV: ##STR38## which comprises: (1) coupling an amino acid of the formula: ##STR39## wherein G is a carboxyl protecting group, with a compound of the formula: ##STR40## wherein L is an amino protecting group, in the presence of DCC in a first inert solvent in the presence of a first catalytic agent followed by removal of the carboxyl protecting group G to give a compound of formula I: ##STR41## wherein L is an amino protecting group, followed by: (2) coupling the amino acid of the formula: ##STR42## wherein L is an amino protecting group, with a compound of the formula: ##STR43## in the presence of DCC in a second inert solvent in the presence of a second catalytic agent to give a compound of the formula II: ##STR44## wherein L is an amino protecting group, followed by: (3) reacting the compound of the formula II with a second amino deprotecting agent to give a compound of the formula III, or a pharmaceutically acceptable salt thereof: ##STR45## followed by: reacting the compound of the formula III with methanesulfonic acid to give the compound of formula IV.