Synthesis Of D,l-menthol And Optimization Of Process Conditions

Menthol and its derivatives are important cyclic terpenl, applied in various areas of the fine chemical industry, such as pharmaceutical, additives. Menthol obtained by freezing peppermint and commint oils can not meet the need of industrialization, and production of synthetic menthol was popular. Today the combination of organic synthesis and biology technology has become a new focus. The aim of this work is to prepare d,l-menthol.An optimum processing condition of the synthesis was obtained by studying the synthesis of d,l-menthol from thymol. Through the study on catalyst, solvent, reaction temperature and pressure, amount of catalyst and recycled use, the content was almost 54.0%. In hydrogenation reaction, in the solvent of hexahydrobenzene, when the pressure was 10Mpa, temperature 150℃, raney nickel RTH-411 can be use for 5 times. The experiment demonstrates that this process is simple, and easy to industrialisation.The article studied the key step of the synthesis of menthol from isoprene, which is the preparation of N,N-diethyl-3,7-dimethylocta-2,6-dien-1-amine. In detail the effects of reaction temperature, reaction time, and reactant ratio on this reaction were investigated. Under optimum conditions the yield was up to 86.0%. The title compound was identified by GS/MS and ~1H-NMR.