[K2]

I am performing an experiment that requires me to prepare acetaldehyde in DMSO. To save time I would like to prepare the stock solutions a day or 2 before, is that possible(stable) or should i just prepare right before when im going to use it?

[Babcock_Hall]

I am not certain, but I would bear in mind two things.  One is that acetaldehyde is volatile and may evaporate over time.  Two is that I once observed NMR data that was consistent with a displacement by DMSO of a trifluoromethanesulfonate leaving group.  I did not attempt to characterize this product, and therefore my conclusion is somewhat speculative.

[rolnor]

I dont think DMSO will react with acetaldehyde, what product will that be? But the acetaldehyde is very volatile, thats a good point. If the solution is stored refrigerated it will probably freeze.

[phth]

It's a gas at room temperature and conc will cahnge over time. Really easy to distill with an ice bath and a 100 mmhg aspiratior. It will also aldol/oligomerize most notable its 6-membered cyclic trimer

[rolnor]

I had a 1L bottle in my lab as a kid, it started to boil when I removed the cap, I did not know the boilingpoint was 21°C.