1) Synthesis method of intermediate 2-Ethylhexylglycerin Inci ether
In a 500 mL three-necked flask, solid sodium hydroxide, toluene, 2-ethylhexanol, and a phase transfer catalyst, tetrabutylammonium bromide, were sequentially added, and stirred at room temperature for 15 min to make the solution evenly mixed. Heat up 45～50 ℃, drip epichlorohydrin in 30～50min, feed ratio 42-ethylhexanol): (epichlorohydrin): (sodium hydroxide)=1: 1.1～1.2: 1, stir Reaction for 4h, cooled to room temperature. Suction filtration, the filtrate was transferred to a separating funnel to separate out the water phase, and the oil phase was distilled under reduced pressure. When the alkali concentration is about 50%, the yield of 2-Ethylhexylglycerin Inci can reach more than 90%.
2) Preparation of Ethylhexylglycerin Inci
Using boron trifluoride ether as catalyst, according to the molar mass ratio of catalyst and 2-Ethylhexylglycerin Inci ether 1:40, the molar mass ratio of 2-ethylhexyl glycidyl ether and acetone 1:6, add 2 to acetone. -Ethylhexyl glycidyl ether and catalyst react at 20°C for 3h to generate 4-alkoxymethyl-1,3-dioxane solution. Add the terminating agent methylamine aqueous solution according to the molar mass ratio of terminating agent and 2-Ethylhexylglycerin Inci ether 1:8, keep 10～20min, steam excess acetone under reduced pressure. Formic acid and water were added to carry out hydrolysis reaction, and the reaction was carried out at 55° C. for 3h. After the hydrolyzate is separated, the oil phase is neutralized with an alkali, and after washing to neutrality, a stabilizer is added. Carry out molecular distillation, temperature 135～145 ℃, vacuum degree 40～50Pa, finally obtain high-purity Ethylhexylglycerin Inci .