michalJenco - 15-12-2019 at 09:30
Hello fellow chemists.
I'd like to synthesise diethyl acetal and I found this synthesis on Prepchem. However, holding a stoppered flask full of warm/hot acetaldehyde seems ridiculous and like something that could easily
explode the flask. I generally trust Prepchem and most of my syntheses were by their procedures, but this one just doesn't feel right.
What do you think?
DavidJR - 15-12-2019 at 10:20
I am not sure this would be enough to result in the flask actually exploding but there is definitely the risk of spraying the contents everywhere...
I would probably prefer to conduct this in a loosely-closed vessel and with good cooling. I'd also probably use magnetic stirring (in an ice bath)
instead of shaking, even if it took longer. A reflux condenser might not be a bad idea either though I'm not sure if it's really necessary.
[Edited on 15-12-2019 by DavidJR]
michalJenco - 15-12-2019 at 12:39
Slow addition with cooling seems reasonable, but will the reaction even happen at cold temperatures?
DavidJR - 15-12-2019 at 16:38
I don't know.
Dr.Bob - 16-12-2019 at 07:36
If you have a glass pressure tube (Ace ones are good to about 200-300 psi), then I might try this behind a shield. Otherwise, the idea of starting
cold and adding the react slowly is worth trying on a small scale. You could even store the reaction in a cooler on ice or other cold non-food area
(outside in northern areas now). Holding a rubber stopper down manually seems very unsafe and difficult for long. What use is diethylacetal?