Patent ID: 11897911
Assignee: SANOFI
Field: Organic fine chemistry (Chemistry)
Classification: CPC A  C | IPC C

Claim 14:
15. A method for preparing a compound of formula (I-A),, comprising the steps of:
a) oxidation of a compound of formula (X),, wherein B is a heterocyclic nucleobase and P1 and P2 each represents independently a protecting group as defined in the general formula (I) according to claim 1,
by reaction of the compound of formula (X) with an oxidizing reagent, whereby the following compound of formula (XI) is obtained:, and
b) subjecting the compound of formula (XI) to a step of reductive amination in the presence of the compound of formula (XII)

R1-NH2  (XII)

wherein R1 is as defined in the general formula (I) according to claim 1,
for obtaining the compound of formula (I-A):, wherein B is a heterocyclic nucleobase and P1 and P2 each represent independently a protecting group as defined in the general formula (I) according to claim 1.