Methylmagnesium chloride

Methylmagnesium chloride is an organometallic compound with the general formula CH3MgCl. This highly flammable, colorless, and moisture sensitive material is the simplest Grignard reagent and is commercially available, usually as a solution in tetrahydrofuran.

Methylmagnesium chloride
Names
IUPAC name
chlorido(methyl)magnesium
Other names
(chloromagnesio)methane
Identifiers
CAS Number
3D model (JSmol)
ChEBI
ChemSpider
ECHA InfoCard 100.010.573
PubChem CID
UNII
CompTox Dashboard (EPA)
Properties
Chemical formula
 CH3MgCl
Molar mass 74.79 g/mol
Appearance colorless solid
Solubility in water
 Reacts with water
Solubility soluble in diethyl ether and THF
Hazards
Main hazards Flammable, Reacts with water
NFPA 704 (fire diamond)
3
3
2
W
Flash point -17°C
Related compounds
Related compounds
 Phenylmagnesium bromide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references

Synthesis and reactions

Relative to the more commonly encountered methylmagnesium bromide[1] and methylmagnesium iodide, methylmagnesium chloride offers the advantages of low equivalent weight and low cost. It is prepared by the reaction of methyl chloride and magnesium in ethyl ether.[2]

Structure of CH3MgCl(thf)2, which is representative of the species in donor solvents.

As with most Grignard reagents, methylmagnesium chloride is highly solvated by ether solvents via coordination from two oxygen atoms to give a tetrahedrally bonded magnesium center.

Like methyllithium, it is the synthetic equivalent to the methyl carbanion synthon. It reacts with water and other protic reagents to give methane, e.g.,:

CH3MgCl + ROH → CH4 + MgCl(OR)

When treated with dioxane, methylmagnesium chloride converts to dimethylmagnesium via the Schlenk equilibrium:

2 CH3MgCl + dioxane → (CH3)2Mg + MgCl2(dioxane)

See also
  • Methylation

Further reading
  • Sakai, Shogo; Jordan, K. D. (1982). "Ab initio study of the structure and vibrational frequencies of the Grignard reagent methylmagnesium chloride". Journal of the American Chemical Society. 104 (14): 4019. doi:10.1021/ja00378a047.

References
  1. Raymond Paul, Olivier Riobé, Michel Maumy (1976). "(E)-4-Hexen-1-ol". Org. Synth. 55: 62. doi:10.15227/orgsyn.055.0062.CS1 maint: uses authors parameter (link)
  2. E. R. Coburn (1947). "3-Penten-2-ol". Org. Synth. 27: 65. doi:10.15227/orgsyn.027.0065.