Crystal structure of tamsulosin hydrochloride, C20H29N2O5SCl

Abstract

The crystal structure of tamsulosin hydrochloride has been solved and refined using synchrotron X-ray powder diffraction data and optimized using density functional techniques. Tamsulosin hydrochloride crystallizes in space groupP21(#4) witha= 7.62988(2),b= 9.27652(2),c= 31.84996(12) Å,β= 93.2221(2)°,V= 2250.734(7) Å3, andZ= 4. In the crystal structure, two arene rings are connected by a carbon chain oriented roughly parallel to thec-axis. The crystal structure is characterized by two slabs of tamsulosin hydrochloride molecules perpendicular to thec-axis. As expected, each of the hydrogens on the protonated nitrogen atoms makes a strong hydrogen bond to one of the chloride anions. The result is to link the cations and anions into columns along theb-axis. One hydrogen atom of each sulfonamide group also makes a hydrogen bond to a chloride anion. The other hydrogen atom of each sulfonamide group forms bifurcated hydrogen bonds to two ether oxygen atoms. The powder pattern is included in the Powder Diffraction File™ as entry 00-065-1415.