3

If I have aniline in acid and fuming $\ce{SO3}$, will it reversibly sufonate? I am worried that the nitrogen will be protonated and reduce the nucleophilicity of benzene ring to the point where sulfonation just isn't possible and instead you just get a salt? Or is it possible that you only get mono-sulfonation?

Here is my reaction scheme:

enter image description here

bon
  • 15,369
  • 13
  • 62
  • 91
gamma1
  • 1,120
  • 1
  • 11
  • 23
  • See this question. Quoting: "Sulfonation [of aniline] is a reversible reaction. (However) The p-isomer, being more stable, does not get desulfonated easily. Hence, p-sulfanilic acid is the major product." – Nilay Ghosh Jun 02 '21 at 06:55

1 Answers1

3

It sulfonates on N first and then rearranges on heating to give sulfonation in the 4 position. JACS 68 (1946) 969

Waylander
  • 22,035
  • 4
  • 37
  • 58