4-Aminopiperidine dihydrochloride is a widely used pharmaceutical intermediate, extensively used in drug synthesis. For example, in the production of a high-content, highly stable, insoluble sulfur for rubber, the process includes the following steps: (1) Sulfur and terpenes are mixed and added to a reactor, ensuring complete removal of air from the reactor, with a vacuum below -0.06 atm; (2) The reactor temperature is raised to 500-520℃, held for 10-15 minutes, then raised to 600-620℃, held for 20-25 minutes, and the gas is injected into a quenching liquid; (3) The resulting viscoelastic material is dried, solidified, pulverized, and sieved to obtain a coarse... (4) Pour the crude powder into the extractant, which is a mixture of tetrachloroethylene and xylene in a mass ratio of 1:0.5-2.5. After extraction, dry the powder. (5) Crush the dried powder and sieve it. Add a composite stabilizer of 4-aminopiperidine dihydrochloride, isoprene, and sodium dihydrogen phosphate. Then add oil. This invention uses gasification to prepare insoluble sulfur. By adding different types of stabilizers in the three stages of gasification, extraction, and oil addition, the product has a high content of insoluble sulfur and excellent stability.
