Morphine, also known as Morphine (Chinese alias Morphine; 1,4-oxazecyclohexane; Tetrahydro-1,4-oxazine; 1,4-Oxo-N-hexacyclic ring), which is a colorless oily liquid at normal temperature. Melting point -4.76℃, boiling point 128.3℃.

Density 1.0005g/cm3(20℃). The refractive index is 1.4548. Flash point 38℃ (open cup). It is miscible with water, acetone, benzene, ether, alcohol, ethylene glycol, linseed oil, turpentine and castor oil.

The following manufacturers of N- methylmorpholine introduce the production methods of morpholine.

1. It is obtained by dehydration and cyclization of diethanolamine with sulfuric acid. Adding diethanolamine into a water reaction pot, dropwise adding sulfuric acid below 60 deg c, heating to 185-195 deg c, and keeping the temperature for 30min. Cooling to below 60℃, dropping sodium hydroxide solution to pH=11, cooling, filtering, rectifying filtrate, collecting fractions below 130℃, and the content of refined morpholine can reach above 99.5%. The raw materials of this method are readily available, and it has become the main method for producing morpholine in the world. Morpholine can be prepared by catalytic reaction of dioxane and ammonia gas.

2. It is prepared by dehydration and cyclization of diethanolamine in the presence of sulfuric acid. Adding diethanolamine into a reaction pot, dropwise adding H2SO4 below 60℃, heating to 185-195℃, keeping the temperature for 30min, cooling to 60℃, dropwise adding NaOH solution to make pH=11, cooling and filtering, rectifying filtrate, and collecting fraction below 130℃ as morpholine. Morpholine can also be prepared from diethylene glycol and ammonia in the presence of catalyst and under pressure. The raw materials of this method are easily available, and it has become the main method for producing morpholine in the world.

Refining method: reflux morpholine and sodium metal for 1 hour, and refine by distillation under normal pressure under dry nitrogen flow. Or dry with anhydrous calcium sulfate and fractionating. Or preparing morpholine into oxalate, recrystallizing with 60% ethanol twice, adding concentrated potassium hydroxide aqueous solution to free morpholine, separating, drying with solid potassium hydroxide, drying with sodium metal, and fractionating.

3. It is prepared by the reaction of diethylene glycol and ammonia in the presence of hydrogen and nickel catalyst at 30-40 MPa atmospheric pressure and 150-400℃. Or prepared by reacting diethanolamine with excessive concentrated hydrochloric acid (or concentrated sulfuric acid).

4. Morpholine can be prepared by ring-closing diethanolamine in acidic environment, and then purified by rectification.

High-quality N- methylmorpholine is mainly used in the production of rubber vulcanization accelerator, and also used in the synthesis of surfactants, textile printing and dyeing auxiliaries, medicines and pesticides. Morpholine is also used as catalyst, corrosion inhibitor and optical bleaching agent for butadiene polymerization. Morpholine is also a solvent for dye, resin, wax, gum, casein, etc. Morpholine salts are also widely used, and morpholine hydrochloride is an intermediate of organic synthesis. Morpholine fatty acid salt can be used as a coating agent for the epidermis of fruits or melons and fruits, which can properly inhibit the respiration and prevent the evaporation of water and the atrophy of epidermis.

Because of its unique chemical properties, morpholine has become one of the fine petrochemical products with important commercial applications, which can be used to prepare rubber vulcanization accelerators such as NOBS, DTOS and MDS, rust inhibitors, corrosion inhibitors, detergents, scale removers, analgesics, local anesthetics, sedatives, respiratory system and blood vessel stimulants, surfactants, optical bleaches, fruit preservatives, textile printing and dyeing auxiliaries, etc. It is widely used in rubber, medicine, pesticide, dye, coating and other industries. In medicine, it is used to produce moroxydine, ribavirin, ibuprofen, cough, naproxen, dichloroaniline, sodium phenylacetate and other important drugs.