| Identification | Back Directory | [Name]
lithium hydrogenacetylide | [CAS]
1111-64-4 | [Synonyms]
Lithioethyne
Ethynyllithium
Lithioacetylene
Ethinyl lithiuM
LITHIUM ACETYLENIDE
Monolithium acetylide
lithium hydrogenacetylide | [EINECS(EC#)]
214-182-6 | [Molecular Formula]
C2HLi | [MOL File]
1111-64-4.mol | [Molecular Weight]
31.97 |
| Hazard Information | Back Directory | [Application]
Lithium Acetylide is a reagent for adding Acetylene to ketones, opening epoxides, and ethynylation of alkyl halides.
| [Definition]
ChEBI: An alkynyllithium compound resulting from the replacement of one of the hydrogens of acetylene by lithium. | [Synthesis]
Monolithium lithium acetylide is prepared by treating a THF solution of Acetylene with n-Butyllithium at 78 °C (eq 1). It is critical to keep the temperature at -78 °C. The concentration should be 0.5 M or less. At higher concentrations and temperatures, a white precipitate forms (presumably Dilithium Acetylide), and yields of additional product fall appreciably. Properly formed lithium acetylide in THF should be a clear, colorless solution.
| [Precautions]
Lithium acetylide/THF solution must be used immediately after preparation. It decomposes above -78 °C. A saturated solution of THF/acetylene should not be used during the preparation of lithium acetylide since this may lead to an acetylene atmosphere above the THF. n-Butyllithium dropping through the acetylene atmosphere may react violently. Lithium acetylide is air and moisture sensitive.
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