Patent ID: 9090642
Filing Date: 2015-07-28
Classification: A61K,A61P,C07F,C07H

Abstract:
1. A method for preparing a compound of Formula Ia or Ib: or a pharmaceutically acceptable salt or acid thereof; wherein: each R or any two R each Base is independently a naturally occurring or modified purine or pyrimidine base linked to the furanose ring through a carbon or nitrogen atom; provided that Base is not uracil; each n is independently 0, 1, or 2; each R each R each R each R wherein each (C said method comprising: (a) providing a compound of Formula II and (b) treating the compound of Formula II with a compound of Formula IIIa and a base thereby forming a compound of Formula Ia or (c) treating the compound of Formula II with a compound of Formula IIIb and a base thereby forming a compound of Formula Ib; wherein: each Ar is a (C wherein: each R each R each R wherein each (C each Ar is a (C said method comprising: (d) providing a diastereomeric compound of Formula VIII and (e) dissolving the compound of Formula VIII in a suitable solvent and inducing crystallization by addition of a C thereby forming a pure diasteromer of Formula IIIa or Formula IIIb.