3-(2-对甲苯基乙烯基)-5(4H)-异噁唑酮的合成、晶体结构、1H NMR及其异构化研究

采用甲硫酯与NH2OH·HCl在室温条件下反应,合成了3-(2-对甲苯基乙烯基)-5(4H)-异唑酮,通过单晶X射线衍射确定了产物的结构.由1HNMR确定的构型与晶体结构完全一致,表明标题化合物在弱极性溶剂(如乙醚和氯仿)中是稳定的.半经验AM1和PM3计算的C7和C8净电荷(分别为-0.077,-0.101)可能是H7和H8化学位移(分别为6.83和6.96)很接近的主要原因.B3LYP/6-311G**基组计算的异构体能量数据表明,3-(2-对甲苯基乙烯基)-5(4H)-异唑酮是最稳定的构型

Synthesis, Single Crystal Structure and 1H NMR Characterization of 3-(2-p-Methylphenylvinyl)-5(4H)-isoxazolone and Theoretical Study for Its Isomerization

p-Methylphenylvinyl)-5(4H)-isoxazolone was synthesized by the reaction of methylthio ester with NH2OH·HCl at room temperature and its structure was characterized by single crystal X-ray diffraction. The configuration based on 1H NMR spectrum in CDCl3 is in agreement with the crystal structure, which indicates that the titled compound is stable in poorly polar solvents, such as diethyl ether and CHCl 3. For 3-(p-methylphenylvinyl)-5(4H)-isoxazolone, the net-charge of C7 is -0.077 and that of C8 is -0.101 by semi-experiential calculations with AM1 and PM3 methods, which are responsible for the chemical shift of H7(6.83) and H8(6.96). With the B3LYP/6-311G** calculation, the 3-(p-Methylphenylvinyl)-5(4H)-isoxazolone is the most stable configuration among the three isomers.