tryagain - 14-6-2007 at 11:03
I dried alkyl bromide and alkyl chloride (primary and secondary halides, freshly opened from commercial bottle) with CaH2 before. Could I dry alkyl
iodide with CaH2 as well? P2O5 might be a good choice, but I want to remove HI as well.
Thanks a lot.
vulture - 14-6-2007 at 13:21
Do NOT crosspost.
I doubt CaH2 is a good idea unless you want an alkane.
Ozone - 14-6-2007 at 17:49
Most of the alkyl halides that I have used do not tend to get too wet. Granular Na2SO4 followed by MgSO4 usually does the trick.
If you are really worried, distill them onto molecular sieves. Avoid alkali metals (alkali in general), hydrides and aluminum.
Freshly opened from a commercial bottle? These are probably OK as-is. If you are worried, use a slight excess (for example, with a Friedel-Crafts
rxn); the AlCl3, also in excess, will take care of any moisture you might have. For Grignards, however, I would suggest the drying over mol sieves
(although, *good* commercial (at least ACS grade) material has worked just fine in the past)
What are you trying to do? This effects how you treat the material.
O3