87583-89-9

51066-08-1

74-89-5

61798-24-1

The reaction was catalyzed by 2.5 g of inorganic boric acid with epoxycyclohexane (98.2 g, 1.0 mol) and monomethylamine (35% aqueous solution, 1.0 mol) at 50 °C for 2 hours. After the reaction was completed, it was cooled to 0 °C, and 0% sulfuric acid solution (1.0 mol) was slowly added dropwise, controlling the temperature not to exceed 40 °C during the dropwise addition. Subsequently, the temperature was raised to 110 °C to remove water under atmospheric pressure until no water flowed out and the reaction system gradually became viscous. After the addition of 85 mL of cyclobutanesulfone, it was changed to vacuum distillation, and the temperature was gradually increased to 140 °C and maintained for 7-8 h until the moisture content was reduced to 0.38%. Cool the reaction solution to 0 ℃, dropwise add sodium hydroxide aqueous solution to adjust the pH to 12-13. slowly warmed to 75 ℃, the reaction solution gradually clarified, cooled to room temperature and separated the upper layer of liquid 81.9 g, GC purity of 95.2%, the yield of the first two steps was 70%. Add the upper liquid with 35% aqueous methylamine (1.12 mol) and 1.4g of inorganic boric acid into the autoclave, sealed and heated to 90 ℃ overnight, the reaction was completed (external standard yield of 96%). After cooling, the water and the pre-fraction were removed by distillation under reduced pressure to obtain pure N,N'-dimethyl-1,2-cyclohexanediamine. Combining the former fractions, a total of 88.6 g of colorless liquid with 89% yield was obtained, which was nearly white solid after cooling, and the GC purity was 99.2%.