Identification | More | [Name]
METHYLLITHIUM | [CAS]
917-54-4 | [Synonyms]
LITHIUM METHANIDE LITHIUM METHYL MELI METHYLLITHIUM methyl-lithiu Methyllithium lithium bromide complex solution Methyllithium solution MethyllithiumcomplexedwithlithiumbromideinethyletherMc METHYLLITHIUM SOLUTION, ~5 % IN DIETHYL ETHER METHYLLITHIUM SOL., ~1 M IN CUMENE/THF METHYLLITHIUM, 2.5M SOLUTION IN DIETHOX& METHYLLITHIUM, 1.6M SOLUTION IN DIETHYLETHER 1-2MinEther Lowhalide Methyllithium, 1.6 M solution in diethyl ether (± 5% w/v) Methyllithium,complexedwithlithiumbromideinethylether(1.5M) methyllithium, 1-2m in ether methyllithium, 1-2m in ether, packaged under argon in resealable chemseal Methyllithium, 1-2M in ether, packaged under Argon in resealable ChemSealTM bottles Methyllithium (2.8% in Ethyl Ether, ca. 1.0mol/L) | [EINECS(EC#)]
213-026-4 | [Molecular Formula]
CH3Li | [MDL Number]
MFCD00008253 | [Molecular Weight]
21.98 | [MOL File]
917-54-4.mol |
Chemical Properties | Back Directory | [Appearance]
colorless to yellowish solution | [Melting point ]
70-71℃ | [Boiling point ]
88℃ | [density ]
0.85 g/mL at 20 °C
| [vapor density ]
3 (vs air)
| [Fp ]
5 °F
| [storage temp. ]
2-8°C
| [form ]
Solution | [color ]
Colorless to yellow | [Specific Gravity]
0.83 | [Water Solubility ]
Reacts with water. | [Hydrolytic Sensitivity]
9: reacts extremely rapidly with atmospheric moisture - may be pyrophoric - glove box or sealed system required | [Sensitive ]
Air & Moisture Sensitive | [BRN ]
3587162 | [Exposure limits]
ACGIH: TWA 400 ppm; STEL 500 ppm OSHA: TWA 400 ppm(1200 mg/m3) NIOSH: IDLH 1900 ppm | [Uses]
In Grignard-type reactions. | [CAS DataBase Reference]
917-54-4(CAS DataBase Reference) | [EPA Substance Registry System]
Lithium, methyl- (917-54-4) |
Safety Data | Back Directory | [Hazard Codes ]
F+,C,N,F | [Risk Statements ]
R12:Extremely Flammable. R15:Contact with water liberates extremely flammable gases. R17:Spontaneously flammable in air. R22:Harmful if swallowed. R34:Causes burns. R66:Repeated exposure may cause skin dryness or cracking. R67:Vapors may cause drowsiness and dizziness. R65:Harmful: May cause lung damage if swallowed. R51/53:Toxic to aquatic organisms, may cause long-term adverse effects in the aquatic environment . R11:Highly Flammable. | [Safety Statements ]
S16:Keep away from sources of ignition-No smoking . 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 label where possible) . S43:In case of fire, use ... (indicate in the space the precise type of fire-fighting equipment. If water increases the risk add-Never use water) . S30:Never add water to this product . S60:This material and/or its container must be disposed of as hazardous waste . | [RIDADR ]
UN 3399 4.3/PG 1
| [WGK Germany ]
2
| [F ]
10 | [TSCA ]
Yes | [HazardClass ]
4.3 | [PackingGroup ]
I | [HS Code ]
29319090 |
Hazard Information | Back Directory | [Hazard]
Flammable, dangerous fire and explosionrisk, self-ignites in air. | [Chemical Properties]
Methyllithium is a colorless to yellowish solution, It is insoluble in hydrocarbon solvents although propyllithium and the higher homologues are miscible in hydrocarbons. Methyllithium is soluble in diethyl ether to about 6% by weight at room temperature (with or without lithium bromide) and is a little less soluble in tetrahydrofuran. Cooling of these solutions produces clear, colorless crystals of methyllithium etherate. Methyllithium is stable to about 200°C, at which temperature it disproportionates to dilithiomethane and methane.
| [Application]
Methyllithium solution (1.6M in diethyl ether) has been used for the asymmetric allylic alkylation (AAA) of allylic electrophiles in the presence of a chiral copper catalyst. This protocol leads to the C-C bond formation of tertiary and quaternary stereogenic centers with high enantioselectivity. It can also be used for the synthesis of (?)-salsolidine by reacting with 6,7-dimethoxy-3,4-dihydroisoquinoline in the presence of (?)-sparteine as a chiral ligand. | [Definition]
ChEBI: Methyllithium is an alkyllithium compound and a one-carbon compound. | [Preparation]
Methyllithium is produced industrially by the reaction of methyl chloride or methyl bromide with lithium metal dispersion in diethyl ether. The reaction with methyl chloride yields a solution of methyllithium and a precipitate of lithium chloride which may be readily separated. When methyl bromide is used, the lithium bromide byproduct remains in solution and complexes with the methyllithium. This reduces the reactivity of the methyllithium and, in certain cases, affects its usefulness. On the other hand, the less reactive complex is more stable in diethyl ether. Methyllithium produced from methyl chloride contains only about 0.3 % lithium chloride in a 5 % solution in diethyl ether. It is more reactive than the lithium bromide complex, but decomposes at the rate of 1 % of the contained methyllithium per year (that is 5.00 % solution goes to 4.95 %) at room temperature. The decomposition by ether cleavage results in methane and ethylene formation which increases the pressure in the container on long storage. Methyllithium can be prepared easily in tetrahydrofuran but it has a half-life of only about 2 days at room temperature due to solvent cleavage. |
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