Crystal structure of terazosin hydrochloride dihydrate (Hytrin®), C19H26N5O4Cl(H2O)2

The crystal structure of terazosin hydrochloride dihydrate has been solved and refined using synchrotron X-ray powder diffraction data, and optimized using density functional techniques. Terazosin hydrochloride dihydrate crystallizes in space group P-1 (#2) with a = 10.01402(4), b = 10.89995(4), c = 11.85357(4) angstrom, alpha = 89.5030(3), beta = 71.8503(3), gamma = 66.5632(2)degrees, V = 1118.143(8) angstrom(3), and Z = 2. The terazosin cation occurs in an extended conformation. The crystal structure is dominated by hydrogen bonds. The most notable are the O-H center dot center dot center dot Cl from the water molecules to the chloride anion and N-H center dot center dot center dot Cl from the protonated ring nitrogen to the chloride. The amino group donates protons to each of the two water molecules. The powder pattern has been submitted to ICDD (R) for inclusion in the Powder Diffraction File (TM). (C) 2018 International Centre for Diffraction Data.