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Chemistry Forums for Students => Organic Chemistry Forum => Topic started by: mrd_res on April 13, 2019, 02:05:31 AM

Title: 2-amino-4, 5-dimethoxybenzoic acid
Post by: mrd_res on April 13, 2019, 02:05:31 AM
Hi all!
Has anyone synthesized and isolated 2-Amino-4,5-Dimethoxy Benzoic Acid?  I need it to see if I can use it as an intermediate. 
Title: Re: 2-amino-4, 5-dimethoxybenzoic acid
Post by: wildfyr on April 13, 2019, 08:23:40 AM
Have you checked scifinder?
Title: Re: 2-amino-4, 5-dimethoxybenzoic acid
Post by: mrd_res on April 13, 2019, 10:09:55 AM
Thanks for the suggestion Wildfyr.  I unfortunately do not have access to scifinder,  but from some literature available on net,  i tried nitration of veratric acid followed by reduction using Zn and Fe in acetic acid or methanol as solvents.  I am finding it difficult to isolate the product,  most probably due to presence of the carboxylate as well as amine groups.
Any suggestions would really be helpful!
Title: Re: 2-amino-4, 5-dimethoxybenzoic acid
Post by: rolnor on April 14, 2019, 05:25:39 AM
Catalytic hydrogenation? Then you dont get any by-products.
Title: Re: 2-amino-4, 5-dimethoxybenzoic acid
Post by: mrd_res on April 14, 2019, 12:52:02 PM
Thanks Rolnor for your reply.  I am working on the same with Pd/C and also trying soluble Pd catalysts to get a clean reaction.
Title: Re: 2-amino-4, 5-dimethoxybenzoic acid
Post by: wildfyr on April 14, 2019, 01:43:33 PM
There's a good chance this is a zWitterion which makes it a pain to isolate, since it's very water soluble.

What if you run the reduction in an aprotic solvent like thf, then rotovap it and dump the crude in methanol with a drop of Sulfuric acid. This will give the methyl ester, which should be very simple to isolate. Then you can hydrolyze it at your leisure.

You can also try precipitating the product from aqueous solution with sodium tetraphenyl borate. Makes a salt with terrible water solubility, but good organic solubility.
Title: Re: 2-amino-4, 5-dimethoxybenzoic acid
Post by: kriggy on April 15, 2019, 01:35:00 AM
Isnt the terphenyl borate quite expensive?

In my opinion, the best bet is to reduce using H2, Pd/C in suitable solvent. The Pd/C hydrogenation in my experience gives no byproducts so the isolation is just filtration and evaporation.
Title: Re: 2-amino-4, 5-dimethoxybenzoic acid
Post by: wildfyr on April 15, 2019, 11:24:39 AM
Tetraphenyl borate is not very expensive. Like $2-3/gram