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1. Product Information

CAS RN: 121-45-9

EINECS number: 204-471-5

Molecular formula: C3H9O4P

Molecular weight: 140.0749

2. Physical information of trimethyl phosphite

Appearance and properties: Colorless transparent liquid, with pungent odor, flammable.

Melting point (℃): -78

Boiling point (℃): 112

Relative density (water = 1): 1.05

Relative vapor density (air = 1): 4.3

Flash point (℃): 38 (OC)

Refractive index nD (22 ℃): 1.4095

Viscosity (25 ℃): 0.58mPa · s

Solubility: Insoluble in hot water, soluble in most organic solvents such as ethanol, benzene, acetone and carbon tetrachloride.

Materials to avoid: Strong oxidants, strong bases, water.

Conditions to avoid: Moist air.

3. Product Technology

1. The transesterification method first reacts phenol with phosphorus trichloride to produce triphenyl phosphite, then transesterifies with methanol in the presence of sodium methoxide to produce trimethyl phosphite. The crude ester is distilled to remove residual methanol and phenol to become a finished product.

Raw material consumption quota: phenol (freezing point ≥40 ℃) 237kg / t; phosphorus trichloride (96%) 1396kg / t; methanol (98%) 855kg / t; sodium methoxide (27-31%) 83kg / t

2. The tertiary amine-ammonia method uses xylene as the solvent. Methanol and phosphorus trichloride are esterified in the presence of N, N-dimethylaniline to produce trimethyl phosphite. After washing with water; dehydration; rectification to obtain finished products.

Raw material consumption quota: methanol (95%) 1025kg / t; phosphorus trichloride 1430kg / t; xylene 130kg / t; dimethylaniline 51kg / t

3. In a three-necked flask equipped with a reflux condenser, a dropping funnel and a thermometer, put 0.3 mol of methanol, 0.3 mol of amine and 100 ml of ether. With stable stirring and maintaining a temperature of 7-10, slowly add a solution of 0.1 mol of phosphorus trichloride in 50 ml of ether from the dropping funnel. The reaction is completed in 1 to 1.5 hours. The precipitated amine hydrochloride is filtered off. The filtrate was distilled to remove ether, and then the residue was distilled to obtain trimethyl phosphite.

Four, use:

1. Trimethyl phosphite is an important intermediate for organophosphorus pesticides. It is used in the production of pesticides such as dichlorvos, phosphoramidite, long-acting phosphorus, and insecticide. It is also the main material for making new organic phosphorus flame retardants. And as a synthetic polymerization catalyst and coating additives.

2. Synthesis of phosphonate or phosphate ester compounds: Trimethyl phosphite is a very useful phosphorus reagent. It can undergo Arbuzov rearrangement reaction and Perkow reaction with halogenated hydrocarbons to generate corresponding phosphonate and Phosphate compounds of enol.

Due to the lone pair of electrons on the phosphorus atom in the trimethyl phosphite molecule, it nucleophilically attacks the positively charged carbon atoms to form phosphonate compounds, and can also attack other positively charged heteroatoms, such as the attack The azide compound gives phosphoramide.

3. Deoxygenation (sulfur) reaction: The phosphorus-oxygen bond is relatively stable, and its bond energy is relatively large. Therefore, phosphite can be used as a deoxidizing agent. After deoxygenation, a relatively stable trimethyl phosphate is generated for reducing sulfone or sulfoxide And other compounds. Similarly, trimethyl phosphite can also be used as a desulfurizing agent for certain reactions to generate trimethyl thiophosphate.

4. As a metal ligand: In the trimethyl phosphite molecule, there is a lone pair of electrons on the phosphorus atom, so it can be used as a metal ligand to catalyze certain reactions. For example, trimethyl phosphite can form a stable complex CuI / P (OMe) 3 with cuprous iodide (CuI), which can interact with lithium salts to form copper salts, thereby playing a catalytic role. Trimethyl phosphite, CuI and pyrazine can form a stable complex.

V. Export essential documents for trimethyl phosphite

Cas number: 121-45-9, UN: 121-45-9

Customs Code HS: 29209011

Tax rebate: The current tax refund for trimethyl phosphite is 9%.

Raw materials: raw materials of phosphorus trichloride and methanol.

It belongs to several types of dangerous goods: At present, triphosphite belongs to 3 types of dangerous goods.

Packing: Net weight 200KG / galvanized iron barrel (16 tons for a small cabinet), 1000KG / IB barrel (18 tons for a small cabinet)