Sciencemadness Discussion Board

Obtaining Anthanilic acid from Methyl Red

LHcheM - 6-12-2011 at 04:24

I have a great amount of methyl red which I find useless for indicator purposes only, so recently I cleaved the Diazo bond with zinc in 50% sulphuric acid, zinc granules are used as I don't have powder. The reaction took 2 days to go to completion. During the time, the very deep red solution gradually fades to colorless, and now a clear solution is obtained

Now the problem came: How can I separate the two products and isolate them?? I suppose the only products are anthranilic acid and N,N-Dimethyl-p-aminoaniline right? But as I neutralize the acid I don't get any precipitate (which the aniline should be insoluble) What's wrong with my strategy /reaction??

UnintentionalChaos - 11-12-2011 at 09:22

Do you have a reference for this reductive cleavage of the azo bond? I suspect that you may have just made the hydrazine. Can you find two spots on a TLC or only one?

LHcheM - 14-12-2011 at 04:43

yes, from Organic Chemistry by Solomons and Graham...
it said that Zn or SnCl2 can perform the reductive cleavage

Unfortunately my TLC plates were expired so I need to wait for my orders to arrive, so I can't test that...