Benzylpotassium is an organopotassium compound with the formula C6H5CH2K, an orange powder. Like organo-alkali metal reagents in general, benzyl potassium is highly reactive, so much so that it reacts with most solvents. It is highly air sensitive.
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Names | |
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Other names
Potassium benzyl
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Identifiers | |
3D model (JSmol)
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PubChem CID
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CompTox Dashboard (EPA)
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Properties | |
C7H7K | |
Molar mass | 130.231 g·mol−1 |
Appearance | Orange solid |
Hazards | |
Occupational safety and health (OHS/OSH): | |
Main hazards
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Ignites in air |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Synthesis
editOne early synthesis proceeds by two-step transmetallation reaction by p-tolylpotassium:[1]
- (CH3C6H4)2Hg + 2 K → 2 CH3C6H4K + Hg
- CH3C6H4K → KCH2C6H5
A modern synthesis involves the reaction of butyllithium, potassium tert-butoxide, and toluene.[2] Although potassium hydride can also be used as a strong base for preparing potassium salts, benzyl potassium has the advantage of being molecular and hence more fast-acting.
References
edit- ^ Gilman, Henry; Pacevitz, Henry A; Baine, Ogden (1940). "Benzylalkali Compounds1". Journal of the American Chemical Society. 62 (6): 1514. doi:10.1021/ja01863a054.
- ^ Lochmann, L; Trekoval, J (1987). "Lithium-potassium exchange in alkyllithium/potassium t-pentoxide systems". Journal of Organometallic Chemistry. 326: 1. doi:10.1016/0022-328X(87)80117-1.