Methyldichlorophosphine

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Methyldichlorophosphine
Methyldichlorophosphine.svg
Names
Preferred IUPAC name
Methylphosphonous dichloride
Other names
Methyl phosphonous dichloride, Dichloromethylphosphine, SW [1]
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.010.575 OOjs UI icon edit-ltr-progressive.svg
EC Number
  • 211-631-8
PubChem CID
UN number 2845
  • InChI=1S/CH3Cl2P/c1-4(2)3/h1H3
    Key: CDPKWOKGVUHZFR-UHFFFAOYSA-N
  • CP(Cl)Cl
Properties
CH3Cl2P
Molar mass 116.91 g·mol−1
AppearanceColorless liquid
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

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.

Contents

Preparation

Methyldichlorophosphine is produced by alkylation of phosphorus trichloride with methyl iodide followed by reduction of the resulting phosphonium salt with iron powder: [2] [3] The compound is an intermediate for the synthesis of other chemicals for instance dimethylphenylphosphine:

CH3I + PCl3 + AlCl3 → [CH3PCl3]+AlCl3I
[CH3PCl3]+AlCl3I + Fe → CH3PCl2 + FeClI + AlCl3

Uses

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

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]

Related Research Articles

Iron(III) chloride describes the inorganic compounds with the formula FeCl3(H2O)x. Also called ferric chloride, these compounds are some of the most important and commonplace compounds of iron. They are available both in anhydrous and in hydrated forms which are both hygroscopic. They feature iron in its +3 oxidation state. The anhydrous derivative is a Lewis acid, while all forms are mild oxidizing agent. It is used as a water cleaner and as an etchant for metals.

<span class="mw-page-title-main">Iron(II) chloride</span> Chemical compound

Iron(II) chloride, also known as ferrous chloride, is the chemical compound of formula FeCl2. It is a paramagnetic solid with a high melting point. The compound is white, but typical samples are often off-white. FeCl2 crystallizes from water as the greenish tetrahydrate, which is the form that is most commonly encountered in commerce and the laboratory. There is also a dihydrate. The compound is highly soluble in water, giving pale green solutions.

<span class="mw-page-title-main">Thionyl chloride</span> Inorganic compound (SOCl2)

Thionyl chloride is an inorganic compound with the chemical formula SOCl2. It is a moderately volatile, colourless liquid with an unpleasant acrid odour. Thionyl chloride is primarily used as a chlorinating reagent, with approximately 45,000 tonnes per year being produced during the early 1990s, but is occasionally also used as a solvent. It is toxic, reacts with water, and is also listed under the Chemical Weapons Convention as it may be used for the production of chemical weapons.

<span class="mw-page-title-main">Phosphonium</span> Family of polyatomic cations containing phosphorus

In chemistry, the term phosphonium describes polyatomic cations with the chemical formula PR+
4
. These cations have tetrahedral structures. The salts are generally colorless or take the color of the anions.

<span class="mw-page-title-main">Phosphorus trichloride</span> Chemical compound

Phosphorus trichloride is an inorganic compound with the chemical formula PCl3. A colorless liquid when pure, it is an important industrial chemical, being used for the manufacture of phosphites and other organophosphorus compounds. It is toxic and reacts readily with water to release hydrogen chloride.

<span class="mw-page-title-main">Triphenylphosphine</span> Chemical compound

Triphenylphosphine (IUPAC name: triphenylphosphane) is a common organophosphorus compound with the formula P(C6H5)3 and often abbreviated to PPh3 or Ph3P. It is versatile compound that is widely used as a reagent in organic synthesis and as a ligand for transition metal complexes, including ones that serve as catalysts in organometallic chemistry. PPh3 exists as relatively air stable, colorless crystals at room temperature. It dissolves in non-polar organic solvents such as benzene and diethyl ether.

Diphosphene is a type of organophosphorus compound that has a phosphorus–phosphorus double bond, denoted by R-P=P-R'. These compounds are not common but are of theoretical interest. Normally, compounds with the empirical formula RP exist as rings. However, like other multiple bonds between heavy main-group elements, P=P double bonds can be stabilized by a large steric hindrance from the substitutions. The first isolated diphosphene bis(2,4,6-tri-tert-butylphenyl)diphosphene was exemplified by Masaaki Yoshifuji and his coworkers in 1981, in which diphosphene is stabilized by two bulky phenyl group.

<span class="mw-page-title-main">Palladium(II) chloride</span> Chemical compound

Palladium(II) chloride, also known as palladium dichloride and palladous chloride, are the chemical compounds with the formula PdCl2. PdCl2 is a common starting material in palladium chemistry – palladium-based catalysts are of particular value in organic synthesis. It is prepared by the reaction of chlorine with palladium metal at high temperatures.

In inorganic chemistry, chlorosilanes are a group of reactive, chlorine-containing chemical compounds, related to silane and used in many chemical processes. Each such chemical has at least one silicon-chlorine bond. Trichlorosilane is produced on the largest scale. The parent chlorosilane is silicon tetrachloride.

<span class="mw-page-title-main">Dimethyl methylphosphonate</span> Chemical compound

Dimethyl methylphosphonate is an organophosphorus compound with the chemical formula CH3PO(OCH3)2. It is a colourless liquid, which is primarily used as a flame retardant.

Organophosphorus chemistry is the scientific study of the synthesis and properties of organophosphorus compounds, which are organic compounds containing phosphorus. They are used primarily in pest control as an alternative to chlorinated hydrocarbons that persist in the environment. Some organophosphorus compounds are highly effective insecticides, although some are extremely toxic to humans, including sarin and VX nerve agents.

<span class="mw-page-title-main">Titanium(II) chloride</span> Chemical compound

Titanium(II) chloride is the chemical compound with the formula TiCl2. The black solid has been studied only moderately, probably because of its high reactivity. Ti(II) is a strong reducing agent: it has a high affinity for oxygen and reacts irreversibly with water to produce H2. The usual preparation is the thermal disproportionation of TiCl3 at 500 °C. The reaction is driven by the loss of volatile TiCl4:

Organophosphines are organophosphorus compounds with the formula PRnH3−n, where R is an organic substituent. These compounds can be classified according to the value of n: primary phosphines (n = 1), secondary phosphines (n = 2), tertiary phosphines (n = 3). All adopt pyramidal structures. Organophosphines are generally colorless, lipophilic liquids or solids. The parent of the organophosphines is phosphine (PH3).

Phenylphosphine is an organophosphorus compound with the chemical formula C6H5PH2. It is the phosphorus analog of aniline. Like other primary phosphines, phenylphosphine has an intense penetrating odor and is highly oxidizable. It is mainly used as a precursor to other organophosphorus compounds. It can function as a ligand in coordination chemistry.

Organobromine chemistry is the study of the synthesis and properties of organobromine compounds, also called organobromides, which are organic compounds that contain carbon bonded to bromine. The most pervasive is the naturally produced bromomethane.

<span class="mw-page-title-main">Methylphosphonyl dichloride</span> Chemical compound

Methylphosphonyl dichloride (DC) or dichloro is an organophosphorus compound. It has a number of commercial uses but is most notable as being a precursor to several chemical weapons agents. It is a white crystalline solid that melts slightly above room temperature.

<span class="mw-page-title-main">Dimethylphosphite</span> Chemical compound

Dimethylphosphite is an organophosphorus compound with the formula (CH3O)2P(O)H, known as dimethyl hydrogen phosphite (DMHP). Dimethylphosphite, is a minor tautomer of the phosphorus(V) derivative. It is a reagent for generating other organophosphorus compounds, exploiting the high reactivity of the P-H bond. The molecule is tetrahedral. It is a colorless liquid. The compounds can be prepared by methanolysis of phosphorus trichloride or by heating diethylphosphite in methanol.

In organophosphorus chemistry, an aminophosphine is a compound with the formula R3−nP(NR2)n where R = H or an organic substituent, and n = 0, 1, 2. At one extreme, the parent H2PNH2 is lightly studied and fragile, but at the other extreme tris(dimethylamino)phosphine (P(NMe2)3) is commonly available. Intermediate members are known, such as Ph2PN(H)Ph. These compounds are typically colorless and reactive toward oxygen. They have pyramidal geometry at phosphorus.

In organophosphorus chemistry, the Kinnear–Perren reaction (sometimes the Clay-Kinnear-Perren reaction) is used to prepare alkylphosphonyl dichlorides (RP(O)Cl2) and alkylphosphonate esters (RP(O)(OR')2). The reactants are alkyl chloride, phosphorus trichloride, and aluminium trichloride as catalyst. The reaction proceeds via the alkyltrichlorophosphonium salt:

<span class="mw-page-title-main">Phosphenium</span> Divalent cations of phosphorus

Phosphenium ions, not to be confused with phosphonium or phosphirenium, are divalent cations of phosphorus of the form [PR2]+. Phosphenium ions have long been proposed as reaction intermediates.

References

  1. "Infrared Spectroscopic Observations on the Fate of Organophosphorus Compounds Exposed to Atmospheric Moisture. Part I. G-Agents and Related Compounds" (PDF).
  2. Robert Engel; JaimeLee Iolani Cohen (2004). Synthesis of Carbon–Phosphorus Bonds. CRC. ISBN   0-8493-1617-0.
  3. Mirosław S (1977), "A Simple Preparation of Methylphosphonous Dichloride", Synthesis (7): 450, doi:10.1055/s-1977-24435
  4. "Phosphorus Compounds, Organic", Ullmann's Encyclopedia of Industrial Chemistry (7th ed.), 2007, doi:10.1002/14356007.a19_545.pub2
  5. Sass, S; Morgan, C. U. Chlorination End-Point Indication by Conductivity and Color Change (Step III, DMHP Process). Formal rept.
  6. cit-OPDC. The preparatory manual to chemical warfare. Vol 1: V agents: X
  7. Pubchem. "Dichloro(methyl)phosphane". pubchem.ncbi.nlm.nih.gov. Retrieved 19 April 2018.