metalayer - 16-1-2014 at 07:28
Does a Grignard reaction with 4-chlorophenylmagnesium bromide require anhydrous ether? I know its possible to use wet ether with some Grignard
reagents.
If anhydrous ether is required is a molecular sieve my best option for drying? I need quite a large volume of ether (1400ml)
Thanks!
Dr.Bob - 16-1-2014 at 07:48
For best results, anhydrous is needed. However, the Grignard reagent will react with any water present, once formed, and form 4-chlorobenzene (and
MgOH) from it, eventually removing any water present. So it just comes down to lower yield and purity, plus the reaction may be harder to initiate
in non-anhydrous solvents. But we ran them in organics labs without any special care, and they mostly worked (some students could fail to make them
work with the best reagents, solvents and equipment available). I would guess that if you have near or more than 1% water, it will be a real
problem, but under than might be OK.