Synthesis, Characterization, X-ray Crystal Structure and Safener Activity of Chiral 2-(3-Methyl-2,3-dihydrobenzob 1,4 oxazin-4-yl)-2-oxoethyl Acetate

摘要

The new title compound, chiral 2-(3-methyl-2,3-dihydrobenzo[b][1,4]oxazin-4-yl)-2-oxoethyl acetate, has been synthesized via reduction, cyclization and acylation reaction. The structure of the product has been confirmed by IR, 1H NMR, 13 C NMR, LC-MS(ESI) and single-crystal X-ray diffraction.(R)-2-(3-methyl-2,3-dihydrobenzo[b][1,4]oxazin-4-yl)-2-oxoethyl acetate crystallizes in monoclinic, space group P21/c with a = 11.867(2), b = 8.4087(2), c = 14.325(6) ?, β = 117.59(2)o, Z = 4, V = 1266.9(6) ?3, Dc = 1.307 g/cm3, F(000) = 528, μ(MoK α) = 0.097 mm-1, R = 0.0453 and w R = 0.1237;(S)-2-(3-methyl-2,3-dihydrobenzo[b][1,4]oxazin-4-yl)-2-oxoethyl acetate belongs to the triclinic system, space group P1 with a = 8.2647(17), b = 8.7034(17), c = 9.5479(19) ?, α = 105.33(3), β = 100.95(3), γ = 105.14(3)o, Z = 2, V = 614.1(2) ?~3, Dc = 1.348 g/cm3, F(000) = 264, μ(MoK α) = 0.10 mm-1, R = 0.0613 and w R = 0.1037. Both of the molecules prefer to form crystal packing through C–H···O hydrogen bonds.