[EN] NOVEL PROCESS FOR THE SYNTHESIS OF PHENOXYETHYL DERIVATIVES<br/>[FR] NOUVEAU PROCÉDÉ DE SYNTHÈSE DE DÉRIVÉS DE PHÉNOXYÉTHYLE
申请人:PANACEA BIOTEC LTD
公开号:WO2011101864A1
公开(公告)日:2011-08-25
The present invention provides an improved process for the synthesis of 2-[2- (2,2,2-trifluoroethoxy)phenoxy]ethanol intermediate, its derivatives and/or its pharmaceutically acceptable salts, useful in the synthesis of α-1 adrenoceptor blockers such as silodosin.
Sulfur‐based olefination with Horner–Wadsworth–Emmons‐type mechanism is systematically studied. Nonstabilized and semistabilized carbanion precursors react with carbonyl compounds giving good yields of olefins, and for the latter reagents E isomers of alkenes predominate.
Carbanions of alkanesulfonyl halides and esters react with nonenolizable carbonyl compounds to give olefins. Mechanistic studies reveal that initial aldol-type addition of the carbanions is followed by cyclization–fragmentation to alkenes, and the leaving group on the sulfonyl moiety (RSO2X) controls carbanion stability and rate of the olefin formation.