preparation | step 1. the preparation of N-(S-2, 2-dimethyl-1, 3-dioxolan-4-) methylphthalimide into a 1-liter four-mouth flask connected with stirring, thermometer and condenser tube, adding 250g of N,N-dimethylformamide (DMF), 37.0 grams (0.20 moles) of potassium phthalamide, 33.3 grams (0.22 moles) of R-2, 2-dimethyl-4-chloromethyl-1, 3-dioxolane, 0.5 grams of potassium iodide, heat, and keep the internal temperature between 80-85 ℃ and stir for 4 hours. Cool to 20 ℃, filter, wash the filter cake with 50g DMF, and combine the filtrate. DMF was recovered by vacuum distillation, and the remainder was recrystallized with 80g of methyl tert-butyl ether to obtain 49.7g of N-(S-2, 2-dimethyl-1, 3-dioxolan-4-) methyl phthalimide with 95.3% yield and 99.7% HPLC purity. Step 2. the preparation of S-glycidyl phthalimide into a 500 ml four-mouth bottle with stirring and thermometer, add 200g of 1,2-dichloroethane and 26.5g (0.10 mol) N-(S-2, 2-dimethyl-1, 3-dioxolan-4-) methylphthalimide, 25g of 40% hydrobromic acid, stir and react at 10-15 ℃ for 4 hours. Stratified, the water layer was extracted with 1, 2-dichloroethane 3 times, 20 grams each time, and the organic phase was combined, and the organic phase was transferred to the constant pressure liquid funnel. In another flask, 30g (0.15 mol) of 27% sodium methoxide methanol solution was added, the organic phase was added dropwise between 0-5 ℃, the dropwise after dropping, and the reaction was stirred at 10-15 ℃ for 3 hours. 200g of ice water was added, stratified, the water layer was extracted twice with 1, 2-dichloroethane, 20g each time, the organic phase was combined, 1, 2-dichloroethane was recovered by distillation, and the remainder was recrystallized with 50g of methyl tert-butyl ether to obtain 19.0g of S-glycidyl phthalimide with 93.6% yield and 99.9% HPLC purity. |