IMPROVED PROCESSES FOR PREPARING SUBSTANTIALLY PURE ARFORMOTEROL AND ITS INTERMEDIATES

摘要

Provided herein are improved, convenient and industrially advantageous processes for the preparation of N-[2-hydroxy-5-[(1R)-l-hydroxy-2-[[(1R)-2-(4-methoxyphenyl)-1- methylethyl] amino]ethyl]phenyl]formamide (Arformoterol) or a pharmaceutically acceptable salt thereof, in high yield and purity. Provided further herein is an improved and industrially advantageous process for the preparation of a substantially enantiomerically pure arformoterol intermediate, (R)-4-methoxy-a-methyl-N-(phenylmethyl)benzeneethanamine.