过氧磷钼钨酸盐催化一步法合成2-羟基-1,4-桉树脑

One Step Synthetic Method of 2-Hydroxy-1, 4-Cineole Catalyzed by Peroxoheteropolyoxomolybdotungstate

摘要:

以过氧磷钼钨酸烷基吡啶盐Cat-PMo2W2O24为氧化-酸双功能催化剂，在质量分数为30%的双氧水存在下，催化松油烯-4-醇（Ⅰ）一步合成了2-羟基-1,4-桉树脑（Ⅱ）。溶剂种类、催化剂用量、双氧水用量能明显改变催化反应体系的相态、酸性或酸量，进而影响反应转化率和产率。最佳的反应条件为：松油烯-4-醇12mmol，溶剂氯仿5mL，催化剂用量为4.20%（以松油烯-4-醇的质量百分率计），双氧水用量为0.91（以双氧水与松油烯-4-醇的摩尔比计），反应温度为25℃，反应时间为30min；在该条件下， 松油烯-4-醇的转化率和2-羟基-1,4-桉树脑的产率分别为96.2%和70.1%。

Abstract:

2-Hydroxy-1,4-cineole(Ⅱ) is the intermediate of a botanical cineole derivative herbicide Cinmethylin. It can be obtained from terpinen-4-ol(Ⅰ) via an one-step synthetic method by using peroxoheteropolyoxomolybdotungstate (Cat-PMo2W2O24) as redox–acidic bifunctional catalyst in presence of mass fraction 30 % H2O2 aqueous solution. There were obvious effect of various reaction parameters such as solvent type, catalyst dosage, and the amount of hydrogen peroxide on the phase state, acidity or acid amount of reaction system, resulting in the changes of the conversion rate ofⅠand the yield of Ⅱ. Under the optimum conditions(Ⅰ,12 mmol; chloroform as solvent,5 ml; catalyst dosage,4.20 %(mass fraction, based on the substrate);temperature，25℃; the molar ratio of H2O2 toⅠ, 0.91; reaction time, 30 min.), 96.2% conversion of Ⅰ with 70.1% yield towards Ⅱ was achieved.