C22H25N3, centrally active hypotensive agent, antihypertensive, M(r) = 331.46, monoclinic, P2(1)/c, a = 9.122 (2), b = 22.108 (3), c = 9.165 (2) angstrom, beta = 102.20 (1)degrees, V = 1806.6 angstrom 3, Z = 4, D(x) = 1.22 g cm-3, lambda(Cu K-alpha) = 1.54178 angstrom, mu = 5.67 cm-1, F(000) = 712, room temperature, R = 0.043 for 1360 observed reflections. The methylphenyl substituted nitrogen exhibits sp2 character. The resonance of its axial lone pair with the phenyl ring is evidenced by the shortening of the bridge bond and by the almost parallel position of the phenyl ring and of the mean plane of the piperazine ring.
