Sciencemadness Discussion Board

Need help with a workup after a cleavage

German - 5-4-2020 at 22:12

I added a troc group (trichloroethyl chloroformate) with 2,2,2-Trichloroethoxycarbonyl chloride as part of an N-demethylation. The target molecule crashed out from chloroform when made so it was easy to recover. I also recovered the expected weight after dried. The problem came with cleaving it.

I cleaved the troc group in acetic acid with zinc at rt. I then added water and slowly raised the pH to 7+ with a sodium hydroxide solution. This crashed everything out so I merely filtered it and dried it. The problem is I now have 3 times by weight of what I was expecting to have.

The sodium acetate should have washed out with the water so I don't know what else I recovered in the process. Wikipedia has the cleavage mechanism on it's 2,2,2-Trichloroethoxycarbonyl chloride entry but I don't see what solid products would have come over. I would expect a crap ton of salts but they would have washed out with the water when it was filtered.

Can anyone help? If I just knew what the junk was I can figure out what further workup I must do but I don't know what it could be.

[Edited on 6-4-2020 by German]

[Edited on 6-4-2020 by German]

Metacelsus - 6-4-2020 at 05:23

Try a recrystallization, perhaps? I can't give any advice more specific than that without knowing what your expected product is.

karlos³ - 6-4-2020 at 10:48

Someone never worked a zinc reduction up before.
His product is full of zinc hydroxide(if it even contains the product and is not just simply the zinc he has filtered out).

German - 6-4-2020 at 13:45

Quote: Originally posted by karlos³  

His product is full of zinc hydroxide(if it even contains the product and is not just simply the zinc he has filtered out).


THANK YOU!!!!! Now I should be able to just dissolve the product in alcohol and leave the zinc hydroxide behind. Thanks!

German - 6-4-2020 at 15:46

EDIT: nevermind

[Edited on 7-4-2020 by German]

morganbw - 7-4-2020 at 14:57

Quote: Originally posted by German  
Quote: Originally posted by karlos³  

His product is full of zinc hydroxide(if it even contains the product and is not just simply the zinc he has filtered out).


THANK YOU!!!!! Now I should be able to just dissolve the product in alcohol and leave the zinc hydroxide behind. Thanks!


Please post on how it goes.