cis-1,2-Diaminocyclohexane

286-18-0

1121-22-8

General procedure for the synthesis of trans-1,2-cyclohexanediamine from epoxycyclohexane (CAS:286-18-0): 1. Epoxycyclohexane (39.2 g, 0.4 mol) and 30% ammonia (1.0 mol) were added to a reaction flask and stirred at room temperature for 1.5 h until the solution was clarified and the reaction was complete. 2. The reaction mixture was cooled to room temperature under reduced pressure to obtain a white solid. Add 35g of water to dissolve, cool to 0°C, slowly add 50% aqueous sulfuric acid solution, control the temperature not to exceed 30°C. 3. Stir the reaction mixture, reduce pressure and gradually heat to 80°C to remove water, the system gradually viscous curing stop stirring, continue to vacuum for 4 hours. 4. Remove the solid crushed, continue to raise the temperature to 120 ° C vacuum drying 12 hours, Karl Fischer titration showed water content of 0.22%. 5. In another reaction flask, add sodium hydroxide solution, raise the temperature to 40°C, add the above solid powder in batches, and control the temperature not to exceed 50°C. 6. After completion of the addition, raise the temperature to 60°C, stirring until complete clarification, the reaction was completed and the pH was 9-10. 7. Extracted with 1,2-dichloroethane and distilled to obtain aziridine 27.2 g, GC purity 99.6%, two-step yield 70%. 8. 30% ammonia (0.48 mol) and inorganic boric acid (3.5 g, 56 mmol) were added to aziridine (27.2 g, 0.28 mol) and the reaction was heated to 90-95°C overnight. 9. Upon completion of the reaction, trans-1,2-cyclohexanediamine was obtained by distillation under reduced pressure and solidified by cooling to 28.1 g of white solid with 99.7% GC purity and 88% yield, no cis-isomer was detected, and HNMR was in agreement with literature data.