Jump to content

Benzyl potassium

From Wikipedia, the free encyclopedia
Benzyl potassium
Names
Other names
Potassium benzyl
Identifiers
3D model (JSmol)
ChemSpider
  • InChI=1S/C7H7.K/c1-7-5-3-2-4-6-7;/h2-6H,1H2;
    Key: OQLLVOGBAKFMIS-UHFFFAOYSA-N
  • InChI=1/C7H7.K/c1-7-5-3-2-4-6-7;/h2-6H,1H2;/rC7H7K/c8-6-7-4-2-1-3-5-7/h1-5H,6H2
    Key: OQLLVOGBAKFMIS-QPGMTJJQAI
  • [K]Cc1ccccc1
Properties
C7H7K
Molar mass 130.231 g·mol−1
Appearance Orange solid
Hazards
Occupational safety and health (OHS/OSH):
Main hazards
Ignites in air
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

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.

Synthesis

[edit]

One 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]
  1. ^ Gilman, Henry; Pacevitz, Henry A; Baine, Ogden (1940). "Benzylalkali Compounds1". Journal of the American Chemical Society. 62 (6): 1514. doi:10.1021/ja01863a054.
  2. ^ 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.