Synthesis of methyllithium

Preparation of methyllithium (MeLi · LiBr)

Preparation of methyllithium

Preparation of methyllithium

18 g (2.57 mol) lithium containing 1-3 % of sodium are flattened with a hammer to 1.5 mm thickness and subsequently cut into the flask (chips of 2 x 10 x 1.5 mm) containing 800 ml DRY diethyl ether. The ether is cooled to – 25° and the air purged with dry nitrogen or argon (2 l/min during 1-2 min). In the cooled dropping funnel 104.4 g, (1.1 mol), of methyl bromide (b.p. 4.0 °C) are placed and 10 g are added in one portion. After a few minutes a turbidity appears and a distinct rise of the temperature occurs. When, after about 10 min, the reaction has subsided, the remainder of the methyl bromide is added slowly dropwise over 1 hour period, while keeping the temperature of the mixture between -15 and -20°C. The black coating disappears almost entirely from the lithium metal which has a bright silver-like color. After the addition is complete, stirring is continued at -15°C for an additional hour. The temperature is then allowed to rise to 0° and the glow on the metal gradually disappears. The obtained solution is ten poured into the storage flask, which previously has been filled with inert gas (it is not necessary to filter off the lithium chips). During filtration under inert atmosphere a fast stream (2 to 3 l/min) nitrogen or argon is passed through the reaction flask to protect the solution against attack by oxygen as shown in the picture bellow. Diethyl ether is added to bring the solution to a volume of 1 litre. After gentle shaking or swirling (homogenization), the titer is  determined: this is usually close to 1 molar corresponding to a yield of 90 %.

MeLi · LiI can be obtained in a slightly lower yield (80 %) from methyl iodide and lithium at -10°C.

Preparative Polar Organometallic Chemistry; Vol 1; by L. Brandsma, H. D. Verkruijsse; Springer-Verlag Berlin Heidelberg; 17-18; 1987

IUPAC Name

lithium;carbanide

InChI

InChI=1S/CH3.Li/h1H3;/q-1;+1

InChI Key

IHLVCKWPAMTVTG-UHFFFAOYSA-N

Canonical SMILES

[Li+].[CH3-]

MeSH Synonyms

methyllithium

Depositor-Supplied Synonyms

Methyllithium, Lithium, methyl-, Lithium methanide, 917-54-4, MeLi, Methyl lithium, Methyllithium solution, lithium carbanide, Lithium methide, Methyl-lithium, RFDVAF@, AC1MC45C, KSC487Q1D, 67737_ALDRICH, 197343_ALDRICH, 514330_ALDRICH, 67737_FLUKA, CHEBI:51486, CTK3I7811, CTK5I1135, DVSDBMFJEQPWNO-UHFFFAOYSA-N, MolPort-001-785-785, LITHIUM(1+) ION METHANIDE, EINECS 213-026-4, ANW-39739, EBD210410, AKOS009158984, AKOS015840105, RP18205, RTR-028898, OR034658, OR372248, OR372249, SC-65392, TR-028898, FT-0650698, M1655, I14-19985, 12540-68-0, 33825-29-5

Removed Synonyms

Lime, CID70187, CID2724049

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