MXG - 8-4-2013 at 01:07
I have been making o and p nitrophenol dyes by routine nitration of phenol under mild conditions. This has worked well enough, but what is the black
tary crud that always forms along with my product? I seem to make it no matter how cold I keep it or how slowly I add reactants or how steadily it is
stirred. I know that organic chemistry often makes black crud but I am simply curious what it might be. I sometimes get it with diazotizations too. Is
it some polymer? If it is a side-product what might it be? My own limited analysis hasn't told me too much. Thank-you!
Nicodem - 8-4-2013 at 11:36
You can check with TLC to see if your "black crud" is just a complex mixture of compounds or a true tar (undefinable mixture of polymeric crap).
kristofvagyok - 8-4-2013 at 13:31
In organic chemistry there are always some side reactions what also happens next to your main route, these often form polymers, oxidation products and
a lot thing what you don't want to see, but sadly they are almost always there...
But see the good point: unless the tar is in a smaller percent than your product it couldn't be as bad...
MXG - 8-4-2013 at 15:43
Thank-you for the useful feedback!
I tried the TLC and found where some of my yield has been hiding.
I am encouraged that black crud is not too unusual - I think I will worry about it less in the future.
Thank-you!