论文部分内容阅读
香草醛,目前国内主要是以邻氨基苯甲醚经重氮化水解生成愈创木酚,继后在对亚硝基二甲苯胺及催化剂存在下和甲醛缩合而成;其次便是从造纸废液中回收而得。用一般Reimer-Tiemann(R-T)反应在最佳条件下制得的对位香草醛(PV)的产率仅在10%左右,且以邻位香草醛(OV)居多,在此反应中还发现有2/3的酚未发生反应,可能是反应物难于混匀而得不到充分反应所致。本文以愈创木酚为原料利用改进的 R-T 反应合成了香草醛,引入叔胺作相转移催化剂,结果对位产物增多,总产率增加。
Vanillin, currently mainly o-aminoanisole by diazotization hydrolysis of guaiacol, followed by nitroso-xylene aniline and catalyst in the presence of condensation and formaldehyde; followed by waste from the paper Recycled liquid derived. The yield of para-vanillin (PV) prepared by the general Reimer-Tiemann (RT) reaction was only about 10% under the optimum conditions, and the majority of ortho vanillin (OV) was also found in this reaction 2/3 of the phenol did not react, it may be difficult to mix the reactants and not be fully due to reaction. In this paper, guaiacol was used as raw material to synthesize vanillin with improved R-T reaction. The introduction of tertiary amine as phase transfer catalyst led to the increase of para-product and the increase of total yield.