Sciencemadness Discussion Board

Solvents for LAH reductions?

joe_aldehyde - 28-8-2005 at 07:58

which solvents except plain ether and THF can be used for LAH reductions? i've searched google and well, there is dioxane on the shelf but i'm not sure if it can be used. what about aliphatic hydrocarbons?

[Edited on 28-8-2005 by joe_aldehyde]

solo - 28-8-2005 at 08:40

Quote:

Solubility of lithium aluminum hydride

The solubility of lithium aluminum hydride in grams per 100g of various ethers at 25°C are as follows: diethyl ether 25-30, tetrahydrofuran 13, dibutyl ether 2 and dioxane 0.1. Because of the difficulty of handling the extremely viscous solutions obtained in the first two solvents, the data are of only approximate character.

Reference: J. Am. Chem. Soc. 69, 1199 (1947)




.........source,


http://www.erowid.org/archive/rhodium/chemistry/lah.synthesi...

BromicAcid - 28-8-2005 at 08:57

Strictly regarding solubility (From Hawley's Condensed Chemical Dictionary):
Quote:
Soluble in diethyl ether, tetrahydrofuran, dimthyl "Cellosolve;" slightly soluble in dibutyl ether; insoluble or very slightly soluble in hydrocarbons and dioxane.

joe_aldehyde - 28-8-2005 at 10:37

so i guess for a quick reaction, solubility matters most, right?