Dimethyl chlorothiophosphate
Dimethyl chlorothiophosphate
CAS: 2524-03-0
Molecular Formula: C2H6ClO2PS
Dimethyl chlorothiophosphate - Names and Identifiers
Dimethyl chlorothiophosphate - Physico-chemical Properties
| Molecular Formula | C2H6ClO2PS |
| Molar Mass | 160.56 |
| Density | 1.322g/mLat 25°C(lit.) |
| Boling Point | 66-67°C16mm Hg(lit.) |
| Flash Point | 221°F |
| Water Solubility | slowly hydrolyzes |
| Vapor Presure | 0.67 psi ( 20 °C) |
| Refractive Index | n20/D 1.482(lit.) |
| Physical and Chemical Properties | Methyl chloride is colorless and transparent liquid with pungent smell, B. p. 65 ℃/2.13kPa,n20D 1.4795, 1.3351 relative density, soluble in organic solvent and insoluble in water. Significant isomerization and intermolecular methylation occur at high temperatures. |
Dimethyl chlorothiophosphate - Risk and Safety
| Hazard Symbols | T - Toxic |
| Risk Codes | R23/24/25 - Toxic by inhalation, in contact with skin and if swallowed. R34 - Causes burns R23 - Toxic by inhalation R21/22 - Harmful in contact with skin and if swallowed. |
| Safety Description | S23 - Do not breathe vapour. S26 - In case of contact with eyes, rinse immediately with plenty of water and seek medical advice. S36/37/39 - Wear suitable protective clothing, gloves and eye/face protection. S45 - In case of accident or if you feel unwell, seek medical advice immediately (show the label whenever possible.) S24/25 - Avoid contact with skin and eyes. |
| UN IDs | UN 2267 6.1/PG 2 |
| WGK Germany | 3 |
| RTECS | TD1830000 |
| HS Code | 29309099 |
| Hazard Class | 6.1(a) |
| Packing Group | II |
Dimethyl chlorothiophosphate - References
| NIST chemical information | information provided by: webbook.nist.gov (external link) |
| EPA chemical substance information | information provided by: ofmpeb.epa.gov (external link) |
| Application | O,O-dimethylthiophosphoryl chloride (abbreviated as methyl chloride) is widely used in the synthesis of pesticides, it can be used for the production of organophosphorus insecticides, such as fenthiophos, methyl parathion, triathion, chlorpyrifos methyl, methophos, methamidophos, methamidophos, acephate and bactericide, such as linterophos methyl. This product is a pesticide intermediate, which can be used in the production of trimethoprim, trimethoprim, 1605, methyl 1605, methamidophos and acephate. The product has the toxicity of organophosphorus pesticides, eyes, mucous membranes and skin irritation, inhalation or absorption through the skin will cause poisoning. Mice oral LD50 was 450mg/kg. |
| production method | O-methylthiophosphoryl chloride is produced by the reaction of methanol with phosphoryl trichloride and then further reacted with methanol. 173kg of trichlorosulfon was put into the reaction pan, and the mixture was stirred and cooled to -15 °c. Methanol was slowly added, and the temperature was controlled at about -5 °c. After 161.5kg of methanol was added, the reaction was stirred for 10min. The reaction was washed in cold water at 0 ° C., the layers separated, and the lower layer was O-methylthiophosphoryl chloride (I. E., dichloride). The solid sodium hydroxide was weighed 1.08 times the amount of dichloride, and dissolved in 4 times the weight of methanol to prepare an alcoholic alkali solution. It was cooled to -15 °c and added dropwise to the dichloride, controlling the temperature at around -5 °c. After completion of the addition, the feed liquid was sucked into a water-washing Pan, washed with 1% hydrochloric acid water, left to stand and layered, and the lower layer was O,O-dimethylthiophosphoryl chloride. There are two main routes for the synthesis of methyl chloride. If trichlorosulfon is used as raw material, sodium methoxide method, alcohol-alkali two-step method, water-alkali one-step method and liquid-alkali two-step method are further divided; If phosphorus pentasulfide is used as raw material, it is first made with methanol reaction of dithiophosphate methyl, and then by chlorination, chlorinating agent can be liquid chlorine, thionyl chloride, phosphorus trichloride and phosphorus pentachloride. The domestic industrial production mainly adopts the route of trichlorosulfon. In the past, the alcohol-alkali two-step method and the water-alkali one-step method were mostly used, and the liquid-alkali two-step method is now used. First, the phosphorus trichlorosulfon was cooled to -7 °c and reacted with methanol for 4H, The reaction temperature was controlled below 0 ℃, and the product was washed with water to obtain O-methyl phosphoryl dichloride (dichloro). Put dichloro and methanol into the reaction pan once, stir and cool to -5 ℃, drop liquid alkali (30%) in the processing industry, control the reaction temperature below 0 ℃, stir for 15min after adding, the product was washed with water and left standing to separate out monochloride content> 90%, dichloride content <2%, trimethyl ester content <8%, the yield ranged from 80% to 85% (based on phosphorus trichloride). This method overcomes the difficulty of Solid alkali source in alcohol alkali method and the labor intensity of alcohol alkali preparation, but the yield and content are still low. It has been reported abroad that methyl chloride with high yield and content can be obtained, such as 3mol methanol and 1mol trichlorosulfon at 0~10 ℃, the methyl dichloride can be obtained almost in a quantitative yield and with a purity close to 100. The reaction mixture is quenched with water to separate the organic phase, then 3mol of methanol and 1mol of methyl dichloride are reacted at 0~20 °c in the presence of acid binding agent, and the organic phase is separated after dilution with water, methyl chloride with a purity of more than 96% was obtained with a yield of more than 95%. At present, the phosphorus pentasulfide method is also used to prepare high quality methyl chloride in China. That is, methyl sulfide prepared by a new catalytic process is used as a raw material, Under certain reaction conditions, the average content of methyl chloride is 64.69 and the average yield is 96.05. The obtained by-product sodium sulfide solution was used to refine crude methyl chloride, and the key problems such as sulfur sticking and caking were solved, and the use of cocatalyst was the key technology of the process. The purified chloride obtained was a clear oily substance with an average content of 97.89 and an average yield (in terms of sulfide) of 97.87. The recovered sulfur is sand-like crystal, loose and non-sticky, and easy to filter. |
| toxic substance data | information provided by: pubchem.ncbi.nlm.nih.gov (external link) |
Last Update：2024-04-10 22:29:15
