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香兰醛和邻香兰醛是制药工业和有机合成工业的重要原料,前者还是食品工业和饲料工业的重要添加剂。香兰醛通常以黄樟素,木质素,丁香酚和愈创木酚为原料加工合成。本文用相转移催化的方法,将愈创木酚经Reimer-Tiemann反应成功地得到了香兰醛和邻香兰醛。通过对不同催化剂、溶剂和反应时间的考察,发现不同类型的催化剂对该反应的影响差别很大,如通常使用的相转移催化剂—冠醚,对该反应的催化效果很差,香兰醛和邻香兰醛的收率均在10%左右,而其它类型的相转移催化剂如荷电的催化剂季铵盐类及非荷电的催化剂胺类其效果均较好。同时发现,反应溶剂的介电常数对收率影响较大,如用四氯化碳(介电常数2.24)、苯(介电常数2.28)、二甲苯(2.57)、氯苯(5.62)作反应溶剂,随着介电常数的增加,香兰醛和邻香兰醛的收率下降。温度对反应的影响是很有趣的,溶剂不同,催化剂不同,要求的反应温度也各异,有的高温(50℃)收率高,有的低温(30℃)收率高。
Vanillin and o-lanal are important raw materials for the pharmaceutical and organic synthesis industries. The former is also an important additive for the food industry and the feed industry. Vanillin is usually safrole, lignin, eugenol and guaiacol as raw material processing and synthesis. In this paper, by the method of phase transfer catalysis, guaiacol and vanillin were successfully obtained by Reimer-Tiemann reaction. Through the investigation of different catalysts, solvents and reaction time, it is found that different types of catalysts have different effects on the reaction, such as the commonly used phase transfer catalyst - crown ether, the catalytic effect of the reaction is poor, vanillin and The yield of o-vanillin is about 10%, while other types of phase-transfer catalysts, such as charged quaternary ammonium salts and non-charged amine catalysts, have good yields. At the same time, it is found that the dielectric constant of the reaction solvent has a great influence on the yield, for example, carbon tetrachloride (dielectric constant 2.24), benzene (dielectric constant 2.28), xylene (2.57) and chlorobenzene Solvent, yields of vanillin and o-vanillin decreased with increasing dielectric constant. The influence of temperature on the reaction is very interesting. Different solvents and different catalysts require different reaction temperatures. Some are high-temperature (50 ° C) high yield and some low-temperature (30 ° C) high yield.