[ocvihwer]

Background: I'm working on a Wittig reaction and I'm using NaH (60% suspension in mineral oil) to deprotonate

My product is very nonpolar and the grease in NaH might be a problem for workup. So I tried to use freshly distilled THF to wash away the grease. I add some THF to NaH/oil suspension and removed the liquid, hoping that THF will dissolve the grease away.

However, I cannot remove all the THF from the NaH solid. I decided to just leave it in there and added DMSO anyway.

Question:

Will the residual THF pose any potential problem?

Thanks!

[rolnor]

I have worked with methylenetriphenylphosphorane and that reagent was in the original paper made with NaH/DMSO. I found that it can be generated with n-BuLi/THF instead wich I find more convenient.
To answer your question, no, THF will not be a problem.

[Dan]

Absolutely agree. DMSO is a total hassle, BuLi or ^tBuOK in THF is much more convenient.

[RedViper9]

Assuming your THF is dry, it should not be a problem (See Williams and Lawton JOC, 2010, 8351.); however, I've always triturated NaH with dry hexane or dry pentane (very flammable!) since the trace solvent is inert and is easily removed after the reaction.

[pgk]

I have used NaH (from mineral oil suspension) in diethyl ether, as a reaction medium. I have got better yields by preliminary washing NaH with petroleum ether (anhydrous, by keeping  over molecular sieves 3-4 Å), followed by washing with diethyl ether than washing with diethyl ether, only.

[discodermolide]

You used to be able to buy 100% NaH from Aldrich.

[RedViper9]

You used to be able to buy 100% NaH from Aldrich.

Is this similar to 60% H₂O₂? I expect in both cases Sigma would be happy to sell it to you, but the DoT won't ship it.

On a side note, has anyone used the KH suspended in a solid wax block?