Sciencemadness Discussion Board

indigo to picric acid

idrbur - 18-12-2015 at 07:58

Yesterday i was reading about picric acid and i read that in old days picric acid was made by nitrating indigo,animal horns etc. But they have not provided much information about process . So,i just added indigo to conc. nitric acid in an icebath and i got a red brown solution and let it sit for half an hour and added the solution to ice cold water and it colour turned dark aquagreen and it settle down . I have idea a that what is that solution .

Can any body plz tell me about the complete process .

hissingnoise - 18-12-2015 at 08:12

Sulphonation might help, as with phenol, but separating PA from the resulting mixture might be bothersome . . .

Its more complex molecular linkages would likely undergo extensive oxidation' leading to a range of byproducts!