Patent ID: 7459556
Filing Date: 2008-12-02
Classification: A61P,C07D

Abstract:
1. A process for preparing a compound having the structural formula I or a pharmaceutically acceptable salt thereof, R is benzyl, -benzyl-R each R R R R R R R comprising a)reacting an amine of formula II wherein R is as defined above, with 2,5-dimethoxytetrahydrofuran or HC(O)(CH 2 ) 2 C(O)H, and with C(O)(CH 2 C(O)OR 4 ) 2 , wherein R 4 is H or alkyl, in a buffer, optionally in the presence of a base, to obtain a compound of formula III b) reacting a compound of formula III with I-R c) optionally converting a compound of formula I wherein R is benzyl, -benzyl-R wherein X is halogen, —OSO 2 CH 3 or —O-(p-toluenesulfonyl) thereby yielding the compound of formula I wherein R is —CH(R 7 ) 2 ; and d) optionally recrystallizing the product of step b) or step c) to obtain a purified product.