Preparation method of (S)-glycidyl acetate_Industrial additives

Overview of the preparation method of (S)-glycidyl acetate

(S)-glycidyl acetate, also called glycidyl acetate, can be prepared in one step from epichlorohydrin and sodium acetate. Liu Gang et al. reported that (S)-glycidyl acetate can be used to synthesize N-methyl-N′-(2-hydroxy-3-acetoxypropyl)imidazole hydrochloride ionic liquid.

Preparation method of (S)-glycidyl acetate Preparation method

Basic copper carbonate

Add 0.3g tetrabutylammonium bromide, 50mL toluene, and 6.6g sodium acetate in sequence to the three-necked flask, stir for 0.5h to fully dissolve, and then add 10mL epoxy chlorine dropwise to the reaction flask. Propane, dripping is completed in about 30 minutes. After the dripping is completed, heat and reflux. The temperature is controlled at about 110°C. Add CaCl₂ to the top of the condenser tube to dry the tube. Use TLC to track the reaction progress (developing agent: petroleum ether: ethyl acetate = 2:1, V/V). Perform TLC experiments at 0, 1, 3, 5, 6, 7h… until the phenomenon disappears on TLC. When it changes, stop reacting. Filter with suction, wash the filter cake with toluene, take the organic phase and wash it with distilled water (20mL×2); then wash it with saturated NaHCO₃ (20mL×2), and use anhydrous MgSO_{4 for the organic phase} Dry, filter, and distill under reduced pressure. Collect the fractions at 100~110°C/15mmHg to obtain light yellow glycidyl acetate with a yield of 42.6%; IR(KB r)ν:3042.5(ν O-C-H), 2987. 2 (ν CH3) , 2879. 1 ( ν CH2) , 1733. 6(νC=O) , 1158. 9 ( ν C-O-C) , 798. 0 (δ O-C-H)c m^-1 .¹H NMR ( MHz , C DCl₃) δ:2.23 (3H, s ,CH 3) , 2.89 (2H, s , OCH₂ ), 2.92 (2H, s,COOCH₂), 3.80 (1H, m, CH).

The epoxy value is determined by the hydrochloric acid acetone method. Calibrate NaOH with potassium hydrogen phthalate, titrate the hydrochloric acid-acetone solution with NaOH, react glycidyl ester with picolinic acid in acetone hydrochloric acid solution for 0.5 h, titrate the above mixture with NaOH to consume NaOH. The measured epoxy value of the prepared glycidyl acetate is 7.9mmol·g ^-1, the theoretical value is 8.62mmol·g^-1, and the product purity is calculated is 91. 6%.