Question

Q. How would you obtain
(i) Picric acid (2, 4, 6 -trinitrophenol) from phenol,
(ii) 2-Methylpropene from 2-methyl- propanol ?

Answer 1

Dear Student
No three-time sulphonation is not possible

It is an electrophilic aromatic substitution reaction. OH group activate the ortho and para position of the ring. When SO₃ H group is attached to one ortho and para position, it reduces the density of electrons at another ortho position. And due to steric hindrance of SO₃ H groups, OH group does not exist on the plane so it can not take part in resonance. Therefore, a further sulphonation at another ortho position is not possible.

Regards