Benzyl potassium

Benzyl potassium
Names
	Other names Potassium benzyl
Identifiers
CAS Number	2785-29-7;
3D model (JSmol)	Interactive image;
ChemSpider	10675000;
PubChem CID	11083915;
CompTox Dashboard (EPA)	DTXSID00454524 ;
	InChI 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;
	SMILES [K]Cc1ccccc1;
Properties
Chemical formula	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). Infobox references

Benzylpotassium is an organopotassium compound with the formula C₆H₅CH₂K. It is 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 via 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.

[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.

[1]

[2]