Sciencemadness Discussion Board

benzaldehyde adduct questions...

nzlostpass - 14-10-2020 at 16:14

When making the adduct from it possible to do so if the Benzaldehyde is in DCM? Or does the dcm need distilled off first?

Also...if theres a chance it is a cinnamaldehyde/benzaldehyde mix, will this help seperate the mix or will both form adducts? If so then I guess ill need to fractionally distill (by vacuum) first?

Thanks guys.

nzlostpass - 15-10-2020 at 17:05


Steam - 15-10-2020 at 18:36

Might need a bit more information to understand your specific problem. I am guessing your referring to a bisulfite adduct of benzaldehyde? There are lots of posts here on this issue but essentially what you want to do. If you did a liquid liquid extraction with bisulf (aq) and DCM, I recommend doing multiple small extractions rather than one large one! It will help with recovery. In terms of separating out cinnamaldehyde/benzaldehyde I would probably just use chromatography if I was just doing this for fun and didn't want to do any research. I would imagine a bit of research would yield a lot of results on the topic abet from less than savory sources because cinnamaldehyde/benzaldehyde are common precursor chemicals for "cookery". :(
Also, see this article for some help! :)

Fyndium - 16-10-2020 at 01:29

Unless the adduct dissolves in your solvent, it should work well. Different aldehydes are likely too similar in properties to be separated, so they all form an adduct and (preferably) crash out. Adducts are commonly washed with ethanol, ether or similar solvent, and if DCM is suitable for it, you don't have to strip it off first.

I usually just try things out myself if I can't find info on following:

- Google
- Wiki
- SM search engine
- DOI documents

Take a small sample, measure ratios carefully and test your concept and write down everything. If it doesn't work, rethink it. If it works, see if you can improve the yields by recalculating or altering ratios or work practices. When you get it working, scale it up.

And if people would also write their experiences on the web, the tried and true info would be available for everyone. Now, the most common practice is to leech bits of info and posting zero topics, and either they just forget it being too lazy, or they get it working and go on with their lives. If it wouldn't be the case, I bet many "cookery" type people consider their "recipes" as trade secrets.