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US 2016/0244425 A1Published application
A process for the preparation of olopatadine and sylil intermediates thereof
AssigneeLaboratorio Chimico Internazionale S.p.A.
InventorsPaolo Maria FARINA, Renè Ignacio RODRIGUEZ CURIEL, Stefano MAIORANA, Aldo BIANCHI, Federica COLOMBO, Gabriele TIMPANO
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Abstract
The present invention refers to a new “one-pot” process for the preparation of olopatadine via intermediates of formula (III).
Claims14
A process for the preparation of olopatadine of formula (I)
- or a salt thereof, comprising protecting, by means of a silylating agent, isoxepac of formula (II)
- to give a silyl ester derivative thereof of formula (III)
- wherein R1, R2, R3 are selected from alkyl and phenyl, in an aprotic solvent;
- performing the Wittig reaction in the same reaction solution;
- cleaving the protecting group and obtaining olopatadine or a salt thereof, without isolating any intermediate compound.
2 more elements
The process according to claim 11, wherein in phase (i) hydrochloric acid is added and olopatadine hydrochloride is isolated.
Compounds of formula (III)
- wherein R1, R2, R3 are selected from alkyl and phenyl.
Dependencies are inferred from the claim text.