Quick Search
Tetrahydro-p-oxazine is an organic chemical compound having the chemical formula O(CH2CH2)2NH.
This heterocycle features both amine and ether functional groups.
Because of the amine, Tetrahydro-p-oxazine is a base; its conjugate acid is called morpholinium.
For example, Tetrahydro-p-oxazine with hydrochloric acid makes the salt morpholinium chloride.
Tetrahydro-p-oxazine is a colorless liquid with a weak, ammonia- or fish-like odor.
An aqueous solution with a fishlike odor.
CAS Number: 110-91-8
EC Number: 203-815-1
IUPAC Name: Morpholine
Chemical Formula: C4H9NO
Other names: MORPHOLINE, 110-91-8, 1-Oxa-4-azacyclohexane, Diethylene oximide, Tetrahydro-1,4-oxazine, Diethylenimide oxide, Diethyleneimide oxide, Diethylene imidoxide, Drewamine, Tetrahydro-2H-1,4-oxazine, Tetrahydro-p-oxazine, p-Isoxazine, tetrahydro-, morpholin, Tetrahydro-1,4-isoxazine, BASF 238, 138048-80-3, Caswell No. 584, 2H-1,4-Oxazine, tetrahydro-, 4H-1,4-Oxazine, tetrahydro-, NSC 9376, Tetrahydro-p-isoxazine, CCRIS 2482, HSDB 102, EINECS 203-815-1, UNII-8B2ZCK305O, EPA Pesticide Chemical Code 054701, BRN 0102549, 8B2ZCK305O, DTXSID2025688, CHEBI:34856, AI3-01231, NSC-9376, MFCD00005972, C4H9NO, Tetrahydro-4H-1-4-oxazine, DTXCID305688, EC 203-815-1, 4-27-00-00015 (Beilstein Handbook Reference), MORPHOLINE (IARC), MORPHOLINE [IARC], tetrahydro-14-iso-xazine, 1,4-oxazinane, CAS-110-91-8, MORPHOLINE,REAG, MORPHOLINE, PRACT, UN2054, morphline, Morpholine; Molsidomine Imp. E (EP); Molsidomine Impurity E, morpho line, morpholine-, 6LR, Morpholine (BASF), 4H-1, tetrahydro-, MORPHOLINE [MI], Morpholine [UN2054] [Flammable liquid], MORPHOLINE [FCC], DIEYTHYLENE OXIMIDE, MORPHOLINE [HSDB], Morpholine on Rasta Resin, WLN: T6M DOTJ, NCIMech_000154, Tetrahydro-1, 4-isoxazine, NCIOpen2_007748, Oprea1_317540, Tetryhydro-2H-1,4-oxazine, Tetrahydro-4H-1,4-Oxazine, BIDD:ER0297, Morpholine, analytical standard, CHEMBL276518, NSC9376, BCP24054, STR00194, SYB02456, Tox21_202450, Tox21_303240, STL182843, TETRAHYDRO-2H-1, 4-OXAZINE, AKOS000118829, Morpholine, ACS reagent, >=99.0%, Morpholine, ReagentPlus(R), >=99%, DB13669, NA 2054, UN 2054, USEPA/OPP Pesticide Code: 054701, NCGC00249227-01, NCGC00256942-01, NCGC00259999-01, Morpholine, p.a., ACS reagent, 99.0%, DB-030063, Morpholine [UN2054] [Flammable liquid], M0465, NS00010190, EN300-18064, Morpholine purified by distillation from glass, Morpholine, purified by redistillation, >=99.5%, Q410243, 1-Oxa-4-azacyclohexane; Tetrahydro-2H-1,4-oxazine, 1-Oxa-4-azacyclohexane ; Tetrahydro-2H-1,4-oxazine, F2190-0339, InChI=1/C4H9NO/c1-3-6-4-2-5-1/h5H,1-4H, 203-815-1, ScavengePore(TM) phenethyl morpholine, macroporous, 40-70 mesh, extent of labeling: 0.7-1.5 mmol/g loading, StratoSpheres(TM) PL-MPH resin, 50-100 mesh, extent of labeling: 3.0-4.0 mmol/g loading, 1 % cross-linked
Corrosive to tissue and moderately toxic by ingestion and inhalation.
Tetrahydro-p-oxazine, also known as 1, 4-oxazepine and diethylenimine oxide, is a kind of colorless alkaline oily liquid.
Tetrahydro-p-oxazine smells of ammonia and has hygroscopicity.
Tetrahydro-p-oxazine could evaporate with water vapor and miscible with water.
Tetrahydro-p-oxazine is Soluble in acetone, benzene, ether, pentane, methanol, ethanol, carbon tetrachloride, propylene glycol and other organic solvents.
Tetrahydro-p-oxazine could form an explosive mixture with air and the explosion limit is 1.8% to 15.2% (volume fraction).
Tetrahydro-p-oxazine is a secondary amine, and at the same time it has the property of inorganic acid and organic acid, so that it can generate salt and amide.
Tetrahydro-p-oxazine contains secondary amine groups and it has all the typical reaction characteristics of the secondary amine groups.
Tetrahydro-p-oxazine can react with inorganic acid to form a salt, and also can react with organic acid to form salt or amide.
Tetrahydro-p-oxazine can carry out alkylation reactions and it also carry out ketone reaction or Willgerodt reaction with ethylene oxide.
Because of the unique chemical properties of Tetrahydro-p-oxazine, it has become one of the important petrochemical products with important commercial application.
Tetrahydro-p-oxazine can be applied to produce rubber vulcanization accelerators such as NOBS, DTOS and MDS.
And Tetrahydro-p-oxazine is also applied to produce anti-corrosives, anti-corrosion agents, detergents, detergents, analgesics, local anesthetics, sedatives, respiratory and vascular stimulants, surfactants, optical bleach, fruit preservatives, and textile dyeing auxiliaries.
Tetrahydro-p-oxazine also has a wide range of applications in the field of rubber, pharmaceuticals, pesticides, dyes, coatings and other industries.
In medication Tetrahydro-p-oxazine could be applied in the production of morpholine guanidine, virus Ling, ibuprofen, cough must, naproxen, dichloroaniline, sodium phenylacetate and other important drugs.
The two main production method of Tetrahydro-p-oxazine are DEA method (diethanolamine method) and DEA method (diethylene glycol method)
Tetrahydro-p-oxazine is noteworthy that new polymer monomer acrylic morpholine has obtained a rapid development in recent years.
Tetrahydro-p-oxazine could be produced from the reaction between acrylic acid and morpholine.
And Tetrahydro-p-oxazine is a kind of water-soluble monomer, and it is still water-soluble after the polymerization.
So Tetrahydro-p-oxazine could be applied for the modification of aqueous polymers.
Besides, Tetrahydro-p-oxazine is widely used as a reactive diluent for UV curable resins.
With the deepening of applied research, many new specific uses have been developed and Tetrahydro-p-oxazine becomes polymer monomer with rapid development.
Chemical properties
Tetrahydro-p-oxazine is colorless water-absorbing oily liquid and it smells ammonia.
Tetrahydro-p-oxazine is soluble in water and methanol, ethanol, benzene, acetone, ether, ethylene glycol and other commonly used solvents.
Tetrahydro-p-oxazine is a colorless liquid with a weak ammonia or fish-like odor.
The odor threshold is 0.01 ppm.
The chemical reactivity of Tetrahydro-p-oxazine is attributed to the secondary amine function of the molecule; organic condensations, alkylations, and arylations readily occur, with the formation of N-substituted morpholine products of wide diversity.
Ethers are relatively chemically inert, hence the oxygen is of relatively little consequence except as a member of the heterocyclic ring (Texaco Chemical Co. 1982).
Physical properties
Colorless, mobile, oily, hygroscopic, flammable liquid with a weak ammonia-like odor.
Experimentally determined detection and recognition odor threshold concentrations were 40 μg/m3 (11 ppbv) and 25 μg/m3 (70 ppbv), respectively (Hellman and Small, 1974).
Forms explosive vapors at temperatures >35 °C.
Uses
Tetrahydro-p-oxazine is made by dehydrating ethanolamines.
Tetrahydro-p-oxazine's main use is as a rubber accelerator in manufacturing tires.
This process requires high temperature (300°F) and pressure, which increase the hazards.
Tetrahydro-p-oxazine is also used as a boiler water additive, brightener for detergents, and corrosion inhibitor, in the preservation of book paper, in waxes and polishes, and in organic synthesis.
Solvent for resins, waxes, casein, dyes; morpholine compounds used as corrosion inhibitors, insecticides, antiseptics, intermediate for rubber-processing chemicals; corrosion inhibitors; waxes and polishes; optical brighteners
Rubber accelerator, solvent, additive to boilerwater, waxes and polishes, optical brightener fordetergents, corrosion inhibitor, preservation of bookpaper, organic intermediate (catalyst, antioxidants,pharmaceuticals, bactericides, etc.).
For medicine, Tetrahydro-p-oxazine used as the raw materials for rubber accelerator and fluorescent whitening agent.
Tetrahydro-p-oxazine is the intermediates of fungicide dimethomorph and flumorpholine and organophosphate insecticide phosalphos.
Tetrahydro-p-oxazine is mainly used for the production of rubber vulcanization accelerator, but also for surfactant, textile auxiliaries, pharmaceuticals, pesticide synthesis.
Tetrahydro-p-oxazine also used as a catalyst for polymerization of butadiene, corrosion inhibitors, optical bleach, the goods are dyes, resins, wax, early glue, casein and other solvents.
At present, the total production of Tetrahydro-p-oxazine in the world is 3-4 million t/a.
Tetrahydro-p-oxazine salts are also widely used. Morpholine salts like morpholine hydrochloride (10024-89-2) are the organic synthesis of intermediates.
Tetrahydro-p-oxazine fatty acid salt can be used as the coating agent of fruits or vegetables epidermal coating agent, and Tetrahydro-p-oxazine could inhibit the base respiration and prevent the epidermis from evaporation of water and epidermal atrophy.
Tetrahydro-p-oxazine is the main raw materials of accelerator NOBS. for analysis reagents and resins, wax, shellac and other solvents, used in the production of sodium sulfate.
Also used in the manufacture of glass, Paper, Detergent, Soap, Dye, Synthetic fiber, Tanning, Medicine and ceramics industries, Analysis reagents, such as nitrogen determination, dehydrating agent.
Tetrahydro-p-oxazine is used for the analysis of reagents and resins, wax, casein, shellac and a variety of solvents solvent.
Tetrahydro-p-oxazine could produce salt after reacting with inorganic acid, and it also could produce salt or amide after reacting with organic acid.
Tetrahydro-p-oxazine also can be alkylated, and it also could come up a ketone reaction or Willgerodt reaction with ethylene oxide.
Tetrahydro-p-oxazine is a common additive, in parts per million concentrations, for pH adjustment in both fossil fuel and nuclear power plant steam systems.
Tetrahydro-p-oxazine is used because its volatility is about the same as water, so once it is added to the water, its concentration becomes distributed rather evenly in both the water and steam phases.
Tetrahydro-p-oxazine's pH-adjusting qualities then become distributed throughout the steam plant to provide corrosion protection.
Tetrahydro-p-oxazine is often used in conjunction with low concentrations of hydrazine or ammonia to provide a comprehensive all-volatile treatment chemistry for corrosion protection for the steam systems of such plants.
Tetrahydro-p-oxazine decomposes reasonably slowly in the absence of oxygen at the high temperatures and pressures in these steam systems.
Production Methods
Tetrahydro-p-oxazine is produced by reacting diethylene glycol, ammonia, and a small amount of hydrogen over a hydrogenation catalyst at 150-400°C and 30-400 atmospheres with the Tetrahydro-p-oxazine being recovered by fractional distillation.
Various byproducts include 2-(2-aminoethoxy)ethanol and Af-alkylmorpholines (NRC 1981).
Tetrahydro-p-oxazine could be produced by diethanolamine dehydration cyclization derived from sulfuric acid.
Add diethanolamine to the water reaction pot and drop sulfuric acid in the temperature of 60 ℃, then when the temperature heat at 185-195 ℃, incubate it for 30min.
Cool Tetrahydro-p-oxazine to under 60℃ and drop sodium hydroxide solution to pH = 11.
The next steeps are cooling, filtering, filtrating distillation, collecting the following fractions below 130℃.
The content of spermine is suppose to reach more than 99.5%.
The method is easy to obtain raw materials, so Tetrahydro-p-oxazine has become the main method of producing morpholine in the world.
Tetrahydro-p-oxazine also could be produced in the catalytic reaction between dioxane and ammonia gas.
The preparation method is that we could get Morpholine from the presence of sulfuric acid dehydration cyclization diethanolamine In the presence of sulfuric acid ; then add diethanolamine into the reaction kettle and add H2SO4 at a temperature of below 6 °C, then heat Tetrahydro-p-oxazine to 185-195 °C for 30 minutes, cool to 60 °C.
Drop NaOH solution to pH = 11, and the last two steeps is cooling and filtrating.
Tetrahydro-p-oxazine could be collected from the fraction below 130 °C.
We can also get Tetrahydro-p-oxazine from the reaction between diethylene glycol and ammonia in the presence of catalyst and pressure.
The method is easy to obtain raw materials, thus Tetrahydro-p-oxazine is the main method of producing morpholine around the world.
