Patent ID: 8129561

Claim:
A process for preparing a compound of formula (I): wherein R 1 is C 1 -C 4 alkyl; the process comprising: (a) contacting a compound of formula (A): with a compound of formula (B): in the presence of an azodicarboxylate reagent and a phosphine reagent, or in the presence of a combined Mitsunobu reagent, to form a compound of formula (C): wherein X is halogen or triflate and PG 2 is an ester protecting group; (b) contacting the compound of formula (C) with a reducing agent to form a compound of formula (D): (c) contacting the compound of formula (D) with a compound of formula (E): in the presence of a palladium catalyst, optionally a copper salt and/or optionally an organic base to form a compound of formula (F): wherein PG 1 is hydrogen or an amine protecting group; (d) contacting the compound of formula (F) with hydrogen in the presence of a metal catalyst to form the compound of formula (G): (e) removing the PG 1 protecting group, when present, from the compound of formula (G) to provide the compound of formula (I).