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| Names | |
|---|---|
| Preferred IUPAC name
Methylphosphonous dichloride | |
| Other names
Methyl phosphonous dichloride, Dichloromethylphosphine, SW[1]
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| Identifiers | |
3D model (JSmol)
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| ChemSpider | |
| ECHA InfoCard | 100.010.575 |
| EC Number |
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PubChem CID
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| UN number | 2845 |
CompTox Dashboard (EPA)
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| Properties | |
| CH3Cl2P | |
| Molar mass | 116.91 g·mol−1 |
| Appearance | Colorless liquid |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Methyldichlorophosphine (alternatively known as dichloro(methyl)phosphane, SW and methyl phosphonous dichloride) is an organophosphorus compound with the chemical formula CH3PCl2. It is a colorless, corrosive, flammable, and highly reactive liquid with a pungent odor.
Preparation[edit]
Methyldichlorophosphine is produced by alkylation of phosphorus trichloride with methyl iodide followed by reduction of the resulting phosphonium salt with iron powder:[2][3]
- CH3I + PCl3 + AlCl3 → [CH3PCl3]+AlCl3I−
- [CH3PCl3]+AlCl3I− + Fe → CH3PCl2 + FeClI + AlCl3
The compound is an intermediate for the synthesis of other chemicals for instance dimethylphenylphosphine.
Uses[edit]
Methyldichlorophosphine belongs to the group of halophosphines, some of which are used as intermediates in the production of plant protection agents, stabilizers for plastics, and catalysts. It is a precursor of the herbicide Glufosinate. It is also used in the production of flameproofing compounds.[4]
Due to the recycling problem of phosphoryl chloride, SW was adopted in step three of the DMHP process in the preparation of Sarin.[5] SW was also adopted as a standard precursor to V agents, having been used to prepare QL for unitary and binary VX. SW was the first agent adopted to prepare VX in one pot reaction by aqueous medium.[6]
Safety[edit]
It is also toxic if inhaled, can cause burns upon contact with the skin and eyes, and releases fumes of hydrochloric acid in moist environments.[7]
References[edit]
- ^ "Infrared Spectroscopic Observations on the Fate of Organophosphorus Compounds Exposed to Atmospheric Moisture. Part I. G-Agents and Related Compounds" (PDF).
- ^ Robert Engel; JaimeLee Iolani Cohen (2004). Synthesis of Carbon–Phosphorus Bonds. CRC. ISBN 0-8493-1617-0.
- ^ Mirosław S (1977), "A Simple Preparation of Methylphosphonous Dichloride", Synthesis (7): 450, doi:10.1055/s-1977-24435
- ^ "Phosphorus Compounds, Organic", Ullmann's Encyclopedia of Industrial Chemistry (7th ed.), 2007, doi:10.1002/14356007.a19_545.pub2
- ^ Sass, S; Morgan, C. U. Chlorination End-Point Indication by Conductivity and Color Change (Step III, DMHP Process). Formal rept.
- ^ cit-OPDC. The preparatory manual to chemical warfare. Vol 1: V agents: X
- ^ Pubchem. "Dichloro(methyl)phosphane". pubchem.ncbi.nlm.nih.gov. Retrieved 19 April 2018.