Synthesis Of Dihydromyrcenol Catalyzed By Cation Exchange Resin In Total-reflux Tower Reactor

The dihydromyrcenol (DHMOH) is a very important kind of perfume ingredient. There are two means to synthesize DHMOH from dihydromyrcene (DH-M), indirect hydration(two-step method) and direct hydration (one-step method).The technics used in industry scale now is the indirect hydration, the disposal of H2SO4 become a serious environment problem. Recently, many articles reported the direct hydration of DHM catalyzed by solid acid, but some got lowconversion, and the other's reaction time was too long. So that it is hard for industrial use.DHMOH was synthesized from DHM and H2O in a total-reflux tower reactor catalyzed by cation exchange resin D61 using 2-propanol as solvent. The various influencing factors like catalyst and it's dosage, solvent, reaction time and reaction material ratio were tested. The performance in reaction kettle and total-reflux tower reactor was studied, the former gave DHM conversion only 66.0%, while nearly 97.9% was obtained for the latter.The optimum reaction conditions were: the dosage of D61 cation exchange resin (catalyst) was 18g/(10mlDHM), reaction time was 28h, and reaction material ratio V(DHM):V(H2O):V(2-propanol)=10:20:20.