[RaInBowDaSh1488]

I am attempting to synthesis 4,5-dimethoxy-1,2-diaminobenzene from 4,5-dimethoxyveratrole. To do this, I have attempted reductions with Sn and Zn in acid solutions. These reactions produce the desired product and have no side reactions; NMR shows no other organic products.

The problem is, when I do the basic workup I run into some sort of trouble. The product I get is a heterogeneous mix of discolored (dark purple almost black) solid mixed with white crystals. When doing the basic workup for both Zn and Sn reductions, the solution turns black when it becomes basic. I have no clue what this black crap is, but it is soluble in both the aqueous and organic solvents. I've tried to remove it by using a column with silica and silica/KF in case it was some sort of tin compound, neither have worked. The reaction works great, I just think the basic workup is creating some inorganic impurities that I can't identify or remove and they are messing up my attempts to use the product for further reactions.

Does anyone have any idea what this black crap being produced when I adjust the PH is? I'd also appreciate any suggestions for how to reduce the nitro groups that does not involve the acid/basic conditions, as I believe I would have no problems if I didn't have to do this in strongly acidic and basic conditions. I'd like to do Pd/C, but I don't have the reagent or the equipment to do this sort of hydrogenation. If anyone knows of a reliable way to reduce aromatic nitros without metals or with catalytic amounts of metal, that would be awesome! I'm getting so desperate I might even try LAH 

[discodermolide]

Lots of suggestions here:
http://en.wikipedia.org/wiki/Reduction_of_nitro_compounds

[RaInBowDaSh1488]

Thanks, yea I've checked online sources and scifinder. In relation to this reaction, the vast majority of the papers use Pd/C which is exactly what I can't do. I was hoping that I might be able to get some input from people that have some practical experience as to either how I can get the basic workup to work. I am also curious as to what might be happening as I make the reaction basic.

I don't do much with amines, but I was sort of thinking that maybe the diamine is polymerizing or forming some kind of azo compound, but I can't see how a base would cause this to happen.

[discodermolide]

As far as I am aware these reductions proceed stepwise via N-nitroso species, which may dimerise and initiate side reactions.
Fe in acetic acid is not one of the worst ways to do it.