Process for preparing salmeterol

摘要

Accordingly, the present invention provides a process for the preparation of a compound of formula (I) or a single enantiomer thereof, or a salt or a solvate thereof, wherein W is a chiral auxilary or hydrogen and P¹ and P² are each independently selected from hydrogen or a protecting group, which comprises: a) treatment of a compound of formula (II), or a salt or a solvate thereof, wherein W is a chiral auxilary and P³ and P⁴ are each independently selected from hydrogen or a protecting group, with a compound formula (III); b) treatment of the resulting product with a reducing agent; c) if required, deprotection to yield the compound of formula (I), or a salt or solvate thereof. In particular there is provided a process for producing a substantially pure single enantiomer of salmeterol