反式茴脑低温氧气氧化性质及其产物

Oxidation Characteristics and Products of trans-Anethole with Oxygen at Low Temperature

考察了反式茴脑氧化反应特性,采用自行设计的小型密闭压力容器跟踪反应压力变化,利用碘量法分析了过氧化物浓度,利用气相色谱-质谱联用仪分析了反应产物种类。实验结果表明,压力变化显示,反式茴脑氧化过程分3个阶段：首先是缓慢吸收氧气阶段;然后是快速氧化反应阶段;最后是氧化趋于结束阶段。当反应温度为95℃,反应时间为4 h时,过氧化物浓度最大为85.07 mmol/kg;反式茴脑氧化反应产物比较复杂,最主要的产物有茴香醛、乙醛、茴香环氧化物、茴香二醇、茴香偶酰等,当反应温度为55℃时,茴香醛选择性达到70.36%。

The oxidation characteristic and pressure of trans-anethole were determined using a self-designed mini closed pressure vessel device. Peroxide concentration was measured by iodimetry, and reaction products were analyzed by gas chromatography-mass spectrometry（GC-MS）. Results showed that the oxidation reaction of trans-anethole with oxygen included three stages： first, oxygen was absorbed slowly, then the oxidation reaction of trans-anethole occurred rapidly, finally, oxidation process went to end. The peroxide concentration reached a maximum value of 85.07 mmol/kg when the reaction was carried at 95 ℃ for 4 h. The oxidation products were more complicated, mainly composing of anisaldehyde, acetaldehyde, anethole epoxide, anethole diol and p-anisil. A maximum anisaldehyde selectivity of 70.36% was obtained at 55 ℃.