Question

an acid A (C8H6O2Br) on bromination in the presence of FeBr3 gives two isomers B and C of the formula C8 H6 O2Br2. Vigorous oxidation of A,B,and C gives acids D,E and ,F , respectively. The acid D ,C7H5O2Br is the strongest acid among all the isomers whereas E and F each has molecular formula of C7H4O2Br2. Give structure of A to F with justification.

Answer 1

The given acid A has carboxylic group in it and bromine group. When bromination takes place in the presence of iron bromide, it will give 2 di - bromo derivatives and these derivatives will be isomeric. These groups in an aromatic acid must be at ortho position. On oxidation of  structures A , B and C it will give structure D, E and F respectively. D is strongest acid due to presence of Bromo group at ortho position. The possible structure and reaction of given acid is given in the following image.