METHOD FOR PRODUCING VALIDOL

摘要

The invention relates to the pharmaceutical and chemical industry, and in particular to methods for producing of validol. A method for producing validol comprises the etherification of isovaleric acid with menthol and using a mixture of acidic sodium sulfate and hydrogen chloride. This mixture is produced directly in the etherificator by the interaction between concentrated sulfuric acid H2SO4 and sodium chloride, and serves as a catalyst. The process is carried out at a temperature of 80 +/- 2 DEG C for a duration of 20-21 hours. The acidic sodium sulfate is then dissolved in water, and the isovaleric acid that did not react is washed from the technical grade Validol using a 7 % solution of caustic soda and hot water (40-45 DEG C). Said technical-grade validol is then subjected to vacuum distillation and rinsed with purified water, after which it is left to stand for four hours. The moist validol to be returned into the production cycle is then removed. The disclosed process produces high-purity validol at a low cost, and enables an expensive natural raw material such as menthol to be used economically.