Name | Methyllithium |
Synonyms | MELI METHYLLITHIUM Methyllithium LITHIUM METHYL LITHIUM METHANIDE Methyllithium solution Methyllithium lithium bromide complex solution MethyllithiumcomplexedwithlithiumbromideinethyletherMc |
CAS | 917-54-4 |
EINECS | 213-026-4 |
InChI | InChI=1/CH3.Li/h1H3;/rCH3Li/c1-2/h1H3 |
Molecular Formula | CH3Li |
Molar Mass | 21.98 |
Density | 0.85g/mLat 20°C |
Melting Point | 70-71℃ |
Boling Point | 88℃ |
Flash Point | 5°F |
Water Solubility | Reacts with water. |
Vapor Density | 3 (vs air) |
Appearance | Solution |
Specific Gravity | 0.83 |
Color | Colorless to yellow |
Exposure Limit | ACGIH: TWA 400 ppm; STEL 500 ppmOSHA: TWA 400 ppm(1200 mg/m3)NIOSH: IDLH 1900 ppm |
BRN | 3587162 |
Storage Condition | 2-8°C |
Sensitive | 9: reacts extremely rapidly with atmospheric moisture - may be pyrophoric - glove box or sealed syst |
Risk Codes | 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 R36/37/38 - Irritating to eyes, respiratory system and skin. R36/38 - Irritating to eyes and skin. R19 - May form explosive peroxides R40 - Limited evidence of a carcinogenic effect R36/37 - Irritating to eyes and respiratory system. R37 - Irritating to the respiratory system R14/15 - |
Safety Description | S16 - Keep away from sources of ignition. 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 the label whenever possible.) S43 - In case of fire use ... (there follows the type of fire-fighting equipment to be used.) S30 - Never add water to this product. S60 - This material and its container must be disposed of as hazardous waste. S62 - If swallowed, do not induce vomitting; seek medical advice immediately and show this container or label. S61 - Avoid release to the environment. Refer to special instructions / safety data sheets. S36/37 - Wear suitable protective clothing and gloves. |
UN IDs | UN 3399 4.3/PG 1 |
WGK Germany | 2 |
FLUKA BRAND F CODES | 10 |
TSCA | Yes |
HS Code | 29319090 |
Hazard Class | 4.3 |
Packing Group | I |
EPA chemical substance information | information provided by: ofmpeb.epa.gov (external link) |
Overview | at room temperature, methyl lithium is a colorless transparent to yellowish liquid, extremely sensitive to air and water, and can spontaneous combustion in the air. Density 0.732g/cm3. Freezing point -17 °c. Ether is generally used as the solvent, and is usually formulated to be between 1.00m and 2.50m. Common organic bases and methylation reagents are widely used in organic synthesis and catalysts. |
properties | methyl lithium is an organolithium reagent. Such organometallic compounds of the s-region are oligomeric in either solid or solution. This highly active compound is often used in the synthesis of ethers and in organic synthesis and organometallic chemistry. The reaction involving it needs to be carried out under anhydrous conditions because it reacts vigorously with water. Oxygen and carbon dioxide also cannot coexist with it. Methyl lithium is therefore usually not prepared in advance before use, but can be dissolved in various ether solutions for storage. |
stability | 1. Stable at normal temperature and pressure, avoid contact with oxides, acids and moisture. 2. Non-solvated solids are prone to spontaneous combustion; In the absence of LiBr, methyl lithium in ether is prone to spontaneous combustion; And other common formulations (whether liquid or solid) are not spontaneous combustion. |
uses | methyl lithium can methylate a variety of functional groups, can remove the protective group, synthesize other methylated organometallic reagents, it can be used as a base and a transition metal for reduction. Solvents and halogens have a strong influence on the reaction with Unsolvated methyl lithium. |
Application | methyl lithium is a commonly used organic base and methylation reagent, which is widely used in organic synthesis and catalyst. |
preparation method | the direct synthesis method is the reaction of methyl bromide with a suspension of lithium metal in ether. 2 Li MeBr → LiMe LiBr the product of this reaction is complex, and most commercial methyl lithium is prepared by this method. The halide-free methyl lithium may be prepared from methyl chloride. [1] Lithium chloride precipitates easily in diethyl ether and is therefore not mixed with methyl lithium. Relatively pure methyl lithium can be obtained by filtration. |
quenching method | slowly pour into tetrahydrofuran with a small amount of dry ice, slowly add an excess of 1-mole ethanol, then dilute with water, finally add dilute HCl until the solution becomes clear, and pour into the corresponding waste liquid bucket in the landing fume hood. The problems to be considered in quenching treatment: 1) select the appropriate quenching reagent, fully consider the stability of the product and the ease of post-treatment; 2) If the quenching process will be a lot of heat, quenching must be performed with cooling; 3) do not rely too much on literature and do not monitor the reaction. The reaction can be quenched only when TLC or other analytical means show the end of the reaction; 4) if possible, work-up should be carried out as soon as possible after the quenching. |
Storage Conditions | hermetically stored in a low-temperature, dry and inert gas protected container. |
production method | in a 1-blade, 3-neck bottle equipped with a magnetic stirrer, gas inlet tube, and dry ice condenser tube, put in 800 ml of anhydrous ethyl ether and Tok (2.3g atom) file wire, under continuous stirring 4 to 5 hours to the reaction flask distilled into 100g (1.05 mol) of olfactory methane, the mixture was then stirred for 1 hour. Left overnight in a stream of nitrogen to precipitate insolubles, transfer the supernatant in nitrogen to a dry, rubber-capped reservoir or container |