[speedy007]

Hi, all.
Ive been looking through some old chemistry books, and I came across a few interesting reactions most of which I understood perfectly although im no chemistry expert. However one of the reactions called for a procedure I do not understand: "reaction mixture was filtered and the filtrate was concentrated under vacuum"
If anyone could explain to me how one would perform this procedure, I will be very greatfull.
Thanks in advance for any replies.

[Arkcon]

Sounds pretty trivial to me.  The sample in solution is put into a vessel that can handle vacuum, you pump the air out, and as the solvent evaporates, you keep pumping that vapor out, until you've lost "enough" to get the concentration needed for the next step.  I recognize you're confused, because this is an archaic way of describing this sort of process.  What is typically used is an apparatus called a rotovap.  We discuss this sort of thing often.  What is your exact procedure and application?

[speedy007]

Well that is quite simple
I have looked up the rotovap device and its a pretty expensive piece of equipment. Is there any alternatives to this? I was thinking maybe a vacuum distillation setup would do the job.
The reaction uses THF and ethyl formate as solvents, what again makes me think that an aspirator would be useless in this situation as the vacuum source as the b.p.'s are too high.
Welcome any opinions on the subject.

[Arkcon]

Yes, you're not going to get THF off without gentle heat.  It depends on if your desired product can handle distillation  heat without decomposition.  Also, all you want to do is concentrate, presumably for future steps, not purify.

[speedy007]

The filtrate once concentrated and solidified upon freezing is the final product, the stability of which I'm not too sure about. It has however a b.p. of around 100°C @ 0.03 torr.
Also do you think a professional vacuum pump would be able to strip off THF through the distillation set up?

[zsinger]

Speedy,
Arguably, you could distill off most solvents, but you are talking in the 5-10k range for a vacuum source capable of those harder distillations.  Rotovap is much more lab practical.  Hope this helps.
                -Z