Synthesis,Crystal Structure and Herbicidal Activity of N-(4-Methylbenzyl)-4-(3-fluorophenyl)-4-piperidinol Hydrochloride

A novel compound N-(4-methylbenzyl)-4-(3-fluorophenyl)-4-piperidinol hydrochlo- ride has been synthesized and its structure (C19H23ClFNO, Mr = 335.83) was characterized by elemental analysis, IR, 1H NMR, MS and single-crystal X-ray diffraction analyses. The crystal belongs to the triclinic system, space group P1- with a = 7.2163(6), b = 10.7905(9), c = 12.2651(10) , α = 109.576(2), β = 98.407(2), γ = 95.956(2)°, V = 878.14(13) 3, Z = 2, Dc = 1.270 g/cm3, μ = 0.231 mm–1, F(000) = 356, S = 1.100, the final R = 0.0525 and wR = 0.1425 for 3206 unique reflections (Rint = 0.0140) with 2736 observed ones (I > 2σ(I)). The piperidine ring exhibits a chair conformation. The dihedral angle made by the methyl- and fluoro-substituted benzene rings is 66.84(7)°. There are some intra- and intermolecular hydrogen bonding interactions among the molecules, which stabilize the whole crystal structure. The preliminary biological activity tests indicate good herbicidal activity for the title compound, in particular against the roots of some tested plants (such as Brassica campestris L. and Echinochloa crusgallis L.).