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Chemistry Forums for Students => Organic Chemistry Forum => Organic Chemistry Forum for Graduate Students and Professionals => Topic started by: K2 on April 09, 2019, 07:32:32 PM

Title: Acetaldehyde and DMSO
Post by: K2 on April 09, 2019, 07:32:32 PM

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?

Title: Re: Acetaldehyde and DMSO
Post by: Babcock_Hall on April 11, 2019, 09:25:16 AM

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.

Title: Re: Acetaldehyde and DMSO
Post by: rolnor on April 11, 2019, 10:12:49 AM

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.

Title: Re: Acetaldehyde and DMSO
Post by: phth on April 12, 2019, 01:45:03 AM

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

Title: Re: Acetaldehyde and DMSO
Post by: rolnor on April 12, 2019, 07:39:26 AM

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.