BENZYLLITHIUM Property

solubility 

sol ethers; DABCO complex crystallizes from hexane as it forms.

Hazard and Precautionary Statements (GHS)

Symbol(GHS)

Signal word

Danger

Hazard statements

H250Catches fire spontaneously if exposed to air

H314Causes severe skin burns and eye damage

Precautionary statements

P210Keep away from heat/sparks/open flames/hot surfaces. — No smoking.

P222Do not allow contact with air.

P260Do not breathe dust/fume/gas/mist/vapours/spray.

P264Wash hands thoroughly after handling.

P264Wash skin thouroughly after handling.

P280Wear protective gloves/protective clothing/eye protection/face protection.

P301+P330+P331IF SWALLOWED: Rinse mouth. Do NOT induce vomiting.

P302+P334IF ON SKIN: Immerse in cool water/wrap in wet bandages.

P303+P361+P353IF ON SKIN (or hair): Remove/Take off Immediately all contaminated clothing. Rinse SKIN with water/shower.

P304+P340IF INHALED: Remove victim to fresh air and Keep at rest in a position comfortable for breathing.

P305+P351+P338IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continuerinsing.

P310Immediately call a POISON CENTER or doctor/physician.

P321Specific treatment (see … on this label).

P363Wash contaminated clothing before reuse.

P370+P378In case of fire: Use … for extinction.

P405Store locked up.

P422Store contents under …

P501Dispose of contents/container to..…

BENZYLLITHIUM Chemical Properties,Usage,Production

Chemical Properties

By X-ray, the DABCO complex forms contact ion pairs with Li over planar benzyl anions and the THF-TMEDA complex has pyramidal benzylic carbon atoms. UV4 and 1H, 13C, and Li NMR studies have been reported.

Uses

Benzyllithium is a benzylating agent in substitutions and additions at carbon and used to attach benzyl groups to other metals and nonmetals.

Preparation

Preparative Methods of Benzyllithium: preparation from benzyl ethyl ether and Lithium in THF/ether is recommended on a large scale; toluene metalation for pure samples. Metalation of toluene with n-Butyllithium/TMEDA gives 90-91% yield, but contaminated with 5-6% m-tolyllithium and 2% each of o- and p-tolyllithium; metalation of toluene with butyllithium/Potassium t-Butoxide, then reaction of the red solid benzylpotassium with LiBr in ether, gives purer product. Preparations from organotin compounds by exchange may be contaminated with organotin compounds. A method involving treatment of benzyl selenides with BuLi at -78 °C should be especially useful for benzyllithiums containing halogens or methoxyls.

storage

Benzyllithium must be prepared and transferred under an inert gas to exclude oxygen and moisture.