Synthesis procedure for picramic acid

[xlivermoron]

I read several synthesis procedures for DDNP and all start with picramic acid which became unavailable from the last US chemical house (Sigma) in 1996. I have found only one synthesis procedure for it in the CIA "Blackbook" Vol. 3 but it is not very precise. There is also a British nitration firm that claims that they use a proprietary process using sodium hydrosulfide, NaHS, as a reducing agent for the NO2 groups on Picric acid (the starting ingredient). The problem is as follows. The reduction of one NO2 group usually does not stop with a single group unless the concentration of NaHS is very low. Too large a concentration of NaHS reduces more than one NO2 which is not picramic acid. So the question is what is the appropriate concentration of NaHS (assuming proper molar balance)? What temperature should the reaction be caried out? What pH should the aqueous solution be? (Maybe the reaction is done in an anhydrous medium??) I would appreciate any guidance from the experimentalists out there.

[Tony Montana]

First off, heres a couple of places that currently sell Picramic acid:
http://www.premdye.com/buy.htm
http://www.norkem.com/P-products.htm
http://www.yickvicchem.com/din21.htm
Secondly, what CIA Black Book Vol.3 are you reading? The only reference to DDNP in the Improvised Munitions Black Books in in Volume 1.
Thirdly, I just posted a recipe in Low explosives, under the title DDNP procedure.(It had a mistake, I stated you need KNO3 or NaNO3, but you actually need KNO2 or NaNO2). That aside it does not start with picramic acid. HINT: picramic acid is produced in that synthesis.

[Mr Cool]

Did you get my e-mail? I hope it helped a bit!