The crystal structure of the title compound, diethyl 5-acetoxy-3-(4-chlorophenyl)-4,5- dihydroisoxazol-5-yl-5-phosphonate (C15H19ClNO6P, Mr = 375.73), has been synthesized by the treatment of nitrile oxides and 1-acetyloxy-vinylphosphonate under very mild conditions in good yields, and determined by single-crystal X-ray diffraction. The crystal belongs to monoclinic, space group C2/c with a = 16.914(10), b = 10.567(7), c = 21.927(13) A, β = 110.249(11)o, V = 3677(4) ·3, Z = 8, Dc = 1.358 g/cm3, F(000) = 1568, μ(MoKa) = 0.324 mm-1, S = 1.011, the final R = 0.0661 and wR = 0.1556. The X-ray analytic results showed that the dihedral angle between the phenyl group and the isoxazoline ring is 10.7o.
A novel and efficient route of synthesizing 1, 2, 4-triazoline-5-ones is reported. The title compounds can be prepared in high yield and purity by the one-pot oxidation and cyclization of 1-acylthiosemicarbazides. The reaction is regioselective and stereoselective. The reaction condition is mild.
