氯酸钠氧化法合成4-氧代-β-紫罗兰酮

Synthesis of 4-oxo-β-ionone by oxidation of sodium chlorate

采用GC-MS方法分析反应产物，对氯酸钠氧化β-紫罗兰酮的反应工艺进行研究，并探讨温度、时间、反应物配比和溶液的pH值对反应的影响。反应产物的结构采用红外光谱、质谱、氢核磁共振谱和元素分析等手段表征。研究结果表明：氯酸钠氧化β-紫罗兰酮的反应主要生成4-氧代-β-紫罗兰酮和5，6-环氧-β-紫罗兰酮，经重结晶和硅胶柱层析分离，纯度高于98％；4-氧代-β-紫罗兰酮的有利合成条件是反应温度为45℃，反应时间为24h，溶液的pH值为1～3，反应物配比n（β-ionone）：n（NaClO3）：n（NaI）为20：100：3，最佳收率为53．5％；5，6-环氧-β-紫罗兰酮有利的合成条件是反应温度为40℃，反应时间为24h，溶液的pH值为3，反应物配比n（pionone）：n（NaClO3）：n（NaI）为20：120：5，其收率为25．4％；未反应的β-紫罗兰酮经减压蒸馏回收后可重复使用。

The procedure of oxidation of β-ionone by sodium chlorate was studied using gas chromatography-mass spectrometry to analyze the reaction products. And their structures were characterized by IR, MS, ^1HNMR and EA. The effect of reaction temperature, reaction time, molar ratio of reactants and pH value of solution were investigated. Results show that 4-oxo-β-ionone is the major product with yield of 53.5% under the conditions as follows, reaction temperature 45℃, reaction time 24 h, the molar ratio of n（β-ionone）：n（NaClO3）：n（NaI） 20：100： 3, and pH value of solution in 1-3; on the other hand, 5, 6-epoxy-β-ionone is major product with yield of 25.4% when reaction temperature is 40℃, reaction time is 24 h, the molar ratio of n（β-io-none）： n（NaClO3） ：n（NaI） is 20：120：5, and pH values of solution is 3. The excessive 13-io-none can be recovered by vacuum distillation for reusing again. 4-oxo-β-ionone and 5, 6-epoxy-β-ionone were purified by recrystallization and silica gel column chromatograph respectively with the purity over 98 %.