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

Claim 16:
17. A method for preparing a compound of formula (I-E) comprising the steps of:
a) transferring the compound of formula (XVII), wherein P1, P2 and B are as defined in the general formula (I) according to claim 1, in the presence of an excess of a sulfonylating agent so as to obtain the compound of formula (XIX), wherein Ts represents a tosyl group,
b) deprotecting the compound of formula (XIX) by removal of group P1 for obtaining the compound of formula (XX), c) subjecting the compound of formula (XX) to a basic condition, so as to obtain the compound of formula (XXI), and
d) replacing the tosyl group by the protecting group P1, so as to obtain the compound of formula (I-E),