Solvents for LAH?

joe_aldehyde · huxleys associate

what solvents can i use for LAH except ethers? i've used TFSE and google and found nothing but THF and Ethers, what about 1,4-Dioxane or even petrol ether...which is no ether, i know i know Wink

thanks for a quick reply, wanna go on holidays soon!

java · Consumer

Solubility of lithium aluminum hydride

stratosphere · Mon Sep 05, 2005 4:03 pm

maybe glyme, which is still an ether but not as volatile and explosive, from my understanding they will dissolve about anything.

Stinging_Nettle · Mon Sep 05, 2005 7:19 pm

Rather than using pure diethylether you can add in toluene or other inert solvents such as hexane. However alcohol or acetonitrile will not work because they will react with the LAH.

simply RED · Sat Sep 10, 2005 3:51 pm

Alcohols will not react with LiAlH4.
Ketones, aldehydes, carboxylic acids and esters - react.
They are reduced to alcohols.

Anyway - diethyl ether and THF remain the best reaction media for LAH.

joe_aldehyde · huxleys associate

alcohols will react with LAH - RED - please go and read a book, make yourself familiar with the matters...if i had believed you i would now probably be dead. THANKS

simply RED · Sun Sep 11, 2005 1:08 am

In my organic chem book there is a statement that LAH does not reduce alcohols.
I searched the net now, and found LAH is not compatable with alcohols!!!
Could you write the reaction that takes place when LAH and alcohol are mixed.

Lego · Sun Sep 11, 2005 2:33 am

simply RED · Mon Sep 12, 2005 2:47 am

Sounds good, only, 4H2 on the right.

Is this reaction fast in room temperature (with EtOH)?

Lego · Mon Sep 12, 2005 9:07 pm

Yes, you are right, should bee 4 H₂

The reaction is fast enough to destroy an excess of LAH after the reduction, even at room temperature, it is common in labs but Lego does not recommend this, as it is very exothermic.