论文部分内容阅读
本发明公开了一种溴乙醛缩二乙醇的合成方法,由下述工艺步骤组成:(1)催化溴化反应:将原料三聚乙醛、铜催化剂、浓硫酸以及无水乙醇搅拌溶解,用冰盐浴冷却,再向反应釜中缓慢滴加单质溴,并在-5℃~0℃反应1h~1.5h,得到溴乙醛的乙醇溶液;(2)缩醛化反应:向上步得到的溴乙醛乙醇溶液中投入无机脱水剂,加热升温至35℃~40℃,保温反应5h~6h后,再加入冰水,反应15min~20min,加入碳酸钠中和反应液,搅拌,静置分层,分出有机层,水层用二氯乙烷提取两次,合并有机相,先减压蒸馏回收溶剂,再减压分馏,收集65℃~68℃馏分,即得高纯度的溴乙醛缩二乙醇;本发明原料易得,反应步骤少,成本低,产品纯度高,质量稳定。
The invention discloses a method for synthesizing bromoacetaldehyde diethyl acetal, which comprises the following process steps: (1) catalytic bromination reaction: the raw material of the trimethylacetaldehyde, copper catalyst, concentrated sulfuric acid and anhydrous ethanol are stirred and dissolved, Cooling with an ice-salt bath, and then dropping the elemental bromine slowly into the reaction kettle and reacting for 1h to 1.5h at -5 ° C to 0 ° C to obtain a bromoacetaldehyde ethanol solution; (2) acetalization reaction: obtaining from the previous step Of bromine acetaldehyde ethanol solution into an inorganic dehydrating agent, heated to 35 ° C ~ 40 ° C, incubated for 5h ~ 6h, then add ice water, the reaction 15min ~ 20min, adding sodium carbonate and the reaction mixture, stirring, standing The organic layer was separated and the aqueous layer was extracted twice with dichloroethane. The organic phases were combined, the solvent was distilled off under reduced pressure, the solvent was distilled off under reduced pressure, and the fraction was distilled off under reduced pressure to collect the distillate of 65 ° C to 68 ° C, Aldehyde diethyl acetal; the raw material of the invention is easy to obtain, the reaction steps are few, the cost is low, the product is of high purity and the quality is stable.