Patent ID: 6884874
Filing Date: 2005-04-26
Classification: A61K,C07C,C07D

Abstract:
1. An N-methyl-L-alanine containing maytansinoid conjugated to a cell-binding agent prepared by a process comprising (1) coupling a compound of Formula VII; where R L is where R M is a direct bond, CH a is 0 or an integer of 1 to 9 when M is a direct bond provided that when M is one or more carbon atoms a is 0 or an integer of 1 to 8; d is an integer of 3 to 8; and Q is H, linear alkyl, branched alkyl, cyclic alkyl, simple or substituted heterocyclic with N-methyl-L-alanine to form a racemization-free compound; (2) forming an N-methyl-L-alanine containing maytansinoid with the said racemization-free compound; and (3) linking said N-methyl-L-alanine containing maytansinoid to the cell-binding agent to form a racemization-free N-methyl-L-alanine containing maytansinoid conjugated to a cell-binding agent.