METHOD FOR PREPARING SILODOSIN

摘要

The present invention relates to a process for preparing silodosin with high optical purity up to 99.9% enantiomeric excess (e.e.) or above. The process makes use of a method step, in which the enantiomers contained in a racemic mixture of a compound represented by the general formula V: wherein * denotes the asymmetric center, R1 is a protecting group, and R2 is cyano or carbamoyl, are separated.

主权项

1. A process for preparing silodosin of formula XXV:or a pharmaceutically acceptable salt thereof, which process comprises the method steps of:
a) separating the enantiomers contained in a racemic mixture of a compound represented by the general formula V: wherein * denotes the asymmetric center, R1 is a protecting group, and R2 is cyano or carbamoyl; b) reacting the R-enantiomer of the compound of formula V (R-V) with a compound represented by formula XXII under reductive animation conditions, or with a compound represented by formula XXIII:wherein X represents a leaving group, to obtain a compound represented by the general formula XXIV: wherein R1 and R2 have the same meaning as defined above; c) deprotecting the compound of formula XXIV and, if R2 is conducting a hydrolysis reaction to afford silodosin; and d) optionally purifying the silodosin obtained in step (c) by crystallization from a solvent.