Question

Orgo II Tutorial: Diazonium and Aniline Reactions

Answer 1

\({\bf{Diazonium:}}\)

starts w/ the reduction of the nitro group (which can of course by added thru nitration) using a variety of mechanisms; the one I will be using is SnCl2 because it's very versatile (apparently)

Answer 2

adding NaNO2 and HCl (the mechanism is very complex and hopefully your professor is reasonable and won't ask for it >_>) will reduce the NH2 into a diazonium (two nitrogens triple bonded to each other, with a positively charged N attached to the R group, in this case, the benzene ring)

Answer 3

from there, you have a very wide range of possibilities

1. adding HBF4 + heat --> replaces the diazonium with a single fluorine. Very useful b/c mono-fluorination is very difficult to control due to fluorine's reactivity.
2. Adding CuCl substitutes w/ chlorine
adding CuBr substitutes w/ bromine
adding CuCN substitutes with a CN triple bond.

obvs. grouping these together for memorization purposes.
3. adding KI will add an iodine (it doesn't mention reaction conditions but I would suspect this is much easier than trying iodinination)
4. adding H3PO2 substitute w/ an H atom
5. adding Cu2O + Cu(2+) will replace with an -OH group (so if you see a synthesis problem w/ an -OH this is your best bet so far)

Answer 4

Anyway, that's the end of my tutorial, I hope it was a helpful resource. Source material is Organic Chemistry 12th edition by Solomons, et. al. and my prof's notes :S