[levis123]

Pd/C + H2 is my go-to system for nitro group reduction quite fast as well most of the time. What is the nitro group positions? Maybe there is some side reaction occuring? ALso, Im not sure but doestn Fe + NH4Cl goes to hydroxylamine instead?

The nitro groups are meta- to each other. I also have a carboxylic acid on the ring at meta- position to both of those. The paper I'm following claims a NO2 to NH2 conversion in these conditions.

Are you following an exact reaction as in the paper? You get an amino acid and it could be water in the product maybe?

The paper has a -Br instead of -COOH at the same position. But how can I avoid the formation of amino acid?

Thats a big difference, the compound you are trying to make is a amino acid and you must think of this when you do the workup, its water soluble both under basic and acidic
conditions. I think in this case Pd/C hydrogenation is better to avoid getting water soluble by-products.

I figured if I extracted with ethyl acetate at acidic pH I would get rid of orange impurities and keep aqueous phase, and then if I raised the pH at around 7 and then extracted from ethyl acetate I would get my product. Do you think that is plausible? If that does not work then I will have to switch to another catalyst. Thanks a lot.

[rolnor]

Yes, there is probably a pH where you can extract but it might be tricky to get it right. Also this compound is very polar so its not easy. Ethyl acetate is a good solvent for this, I think you have to extract several times.
With hydrogenation you only have to filter and evaporate.

[OrganicDan96]

you may need an acid present for catalytic hydrogenation of nitro groups to prevent the resultant amine poisoning the catalyst unless it is done under high pressure. although having said that the carboxylic acid in the molecule may do that job.

[kriggy]

you may need an acid present for catalytic hydrogenation of nitro groups to prevent the resultant amine poisoning the catalyst unless it is done under high pressure. although having said that the carboxylic acid in the molecule may do that job.

Got any resources on that? It explains my observation why my nitro-acid is reduced at 0.01% cat. loading in 2hrs while methyl ester needs 5% overnight