CN102531858A provides a kind of preparation technique of lyral, making up the following steps:
a) Myrcenol is heated to 50 ° C to
130 ° C; b) including acrolein dropwise to the myrcenol gotten symphonious a), controlling the temperature level throughout the going down procedure to be 50 ° C. to 130 ° C., and also continuing the response after the dropwise addition to acquire neoliral. Preferably, in the step b), the going down time of the acrolein is 6h-10h. Ideally, in the step b), the temperature of the response is 50 ° C to 130 ° C. Ideally, in the action b), the time for proceeding the reaction after the dropwise enhancement is 1h-2h. Ideally, the molar ratio of the acrolein to the myrcenol
is 1.1 ˜1.5:1. Preferably, stated action b) specifically consists of the adhering to actions: b1) adding acrolein dropwise to the myrcenol obtained symphonious a);
. b2) cleaning the reaction mixture gotten symphonious b1) in deionized water to obtain the crude lyral;.
b3) subjecting the crude lyral to high vacuum cleaner rectification to get lyral.
Ideally, in the step b3), the vacuum degree during the high vacuum correction is listed below 2 mm Hg.
Preferably, in the step b), the acrolein has 0.1 wt% -0.3 wt% of a polymerization inhibitor.
Preferably, in the action a), the myrcenol consists of 0.1 wt% -0.3 wt% of a polymerization inhibitor.
Preferably, the polymerization inhibitor is hydroquinone, 2,6-di-tert-butyl-p-cresol, 4,4-methylene bis( 2,6-di-tert-butylphenol) or N-phenyl -2- Naphthylamine.
Compared to the previous art, the here and now innovation very first raises the temperature of myrcenol to 50 ° C-130 ° C, then includes acrolein dropwise therein, controls the temperature during the dropping process at 50 ° C-130 ° C, as well as continues the response after the dropwise addition, to get lyral.
In today invention, to start with, myrcenol is heated to 50 ° C to 130 ° C, and then acrolein is added dropwise, to ensure that myrcenol and also acrolein continue to respond and also release warm slowly; throughout the procedure of dropping acrolein, the temperature Always regulate the temperature level at 50 ° C to 130 ° C to stay clear of exothermic response that creates the temperature level of the response system to climb, so regarding prevent the volatilization of acrolein. Lanaldehyde.
In the present innovation, by managing the enhancement method and also temperature level of acrolein, the Diels-Alder response between myrcenol and also acrolein does not require to occur at high temperature as well as stress or under the problems of Lewis acid driver as well as organic solvent, the response conditions are light, and also by-products are less. Given that there is no demand for heat and high pressure, the demands for reaction tools are relatively low, as well as the expense of lyral will certainly not be raised; given that no Lewis acid catalyst is included, cumbersome post-treatment procedures are conserved, and a huge quantity of waste acid will not be produced to wear away devices and contaminate the environment.