chemrox - 24-7-2008 at 16:46
I'm having a problem getting solids out of a two layer reaction mixture following conversion of an alcohol to an alkyl halide using TCT/DMF. I have
solids in both the resultant aqueous and organic layers. The stuff quickly loads up the filter paper and filtration slows to a painfully slow drip.
I was going to try glass wool next. I don't like filtering two phases like this. Is there an obvious other way I missed? The general procedure has
nothing to say about this issue.
Klute - 24-7-2008 at 17:02
You could try filtering through a cotton plug or soemthing to remove most of the solids, and contiçnue with your workup, or add more water to try and
dissolve the salts..
Sauron - 24-7-2008 at 18:15
1. Filter aid, e.g., Celite
2. Glass fritted filter rather than filter paper. Which frit will depend on how fine the solids are.
You will likely need to filter with suction.
chemrox - 25-7-2008 at 07:53
I only have a fine frit.. was thinking of celite also.. wouldn't it just add to the mess holding up the draw? I'll give it a try and let you know.
Sauron - 25-7-2008 at 11:47
Why not use your fine frit filter funnel and vacuum? You can always flush the frit out (in reverse) afterwards.
Or protect it with filter paper on top. Flat on top with celite round the edges. That way none of the solid gets into the frit.
chemrox - 7-10-2008 at 12:38
I really like the process. Good yields on the scale up of the published procedure for converting phenethyl alcohol to chloride using TCT/DMF complex.
The only downside was the amount of solvent required and that can be recovered. For example to make 300 ml of phenethyl chloride one should have a
5L rb and a 5L sep funnel. I got by with a 3L rb, a 2L sep funnel and a gallon jar.