4-Methoxycyclohexylamine hydrochloride can be used as a pharmaceutical synthesis intermediate, such as in the preparation of cis-8-methoxy-1,3-diazaspiro[4,5]dec-2,4-dione: Add 1200 mL of water to a high-pressure reactor, start stirring, add 220 g (2 mol) of 40% formamide, stir for 10 min, then add 130 g (1 mol) of 4-methoxycyclohexylamine hydrochloride, followed by 7 g of rhodium-carbon catalyst. Then, introduce C into the reactor. O, bring the pressure inside the reactor to 0.2 MPa, raise the temperature to 50°C, and keep it at that temperature for 20 hours. When the content of 1-amino-4-methoxycyclohexane in the reaction solution is less than 2%, the reaction ends. Cool down to 25-30°C, add dilute hydrochloric acid dropwise to the reaction solution, and adjust the pH to 5-6. Solid precipitates out. Filter out the product, wash the filter cake once, and obtain 155 g of dried cis-8-methoxy-1,3-diazaspiro[4,5]-dec-2,4-dione, with a yield of 78%.
