Crystal structure of tolazoline hydrochloride

The title compound (C₁₀H₁₂N₂ HC1,M _r =196.7) crystallizes in the monoclinic space groupP2₁/c witha=8.997(1),b=9.665(1) andc=12.290(1) Å,=104.41(1)°,V=1035·1 ų,D _x =1.262 g·cm^–3 forZ=4,=29.4 cm^–1, (CuK)=1.54178 Å,F(000)=416. FinalR=0.051 (R _w =0.063) for 1937 reflections collected on a diffractometer. The structure was solved by direct methods. The two N atoms of the imidazoline ring are equivalent due to protonation and they participate in N-HCl hydrogen bonds which join the molecules into infinite chains. The imidazoline ring is approximately planar and is oriented perpendicular to the plane of the benzene ring. The separations of the two N atoms from the center of the aromatic ring are 4.691(3) and 4.598(3) Å, close to the values found in the crystal structures of clonidinelike agents.