4-Methoxycyclohexylamine

104-94-9

4342-46-5

The general procedure for the synthesis of 4-methoxycyclohexylamine from p-aminoanisole is as follows: 400 mL of anhydrous ethanol was added to a 1000 mL autoclave, followed by the addition of 123 g of p-aminoanisole (1 mol) and 10 g of nickel Nguyenne. After sealing the autoclave, nitrogen was vented to a pressure of 3.0 MPa and held at this pressure for 30 minutes to ensure that there were no leaks in the system. Afterwards, the nitrogen was discharged through the exhaust pipe and the replacement with nitrogen was repeated twice, each time at a pressure of 1.0 MPa, followed by two replacements with hydrogen, each time at the same pressure of 1.0 MPa. After completion of the replacements, the autoclave was charged with hydrogen up to a pressure of 1.5 MPa, stirring was initiated, and the temperature was raised to 120-130°C. After the reaction was initiated, the hydrogen was consumed, and when the pressure dropped to 0.5 MPa, the hydrogen was replenished to 0.5 MPa. MPa, hydrogen was replenished to 2.5 MPa and the reaction pressure was maintained in the range of 2.0-2.5 MPa. The reaction lasted for 20 h, during which hydrogen consumption was monitored. The reaction was considered complete when the remaining feedstock was less than 1%. The reaction system was cooled to 30°C and filtered to remove the catalyst. The filtrate was distilled under reduced pressure (-0.1 MPa) and the 90°C fraction was collected to afford the product 4-methoxycyclohexylamine 125 g in 96.8% yield and 90% product purity.