Question

The importance of Hunsdieker reaction is
(A) it provides very good yields with alkyl halide containing 2 to 18 carbon atoms
(B) this reaction is also possible with chlorine and bromine
(C) both A and B
(D) none of these

Answer 1

An important route to the preparation of halogenated compounds is the Hunsdieker reaction, which is also known as the halo decarboxylation of carboxylic acids. This reaction was improved. The reaction led to it being the general method to produce organic halide.

Complete step by step solution:
A chemical reaction involves the silver salts of carboxylic acids reacting with halogens to form an unstable intermediate and further undergoes decarboxylation thermally leading to the formation of alkyl halides as the final product.
$R-CO{{O}^{-}}+A{{g}^{+}}\underset{CC{{L}_{4}}}{\overset{B{{r}_{2}}}{\mathop \to }}\,R-Br+AgBr+C{{O}_{2}}$
$R-CO{{O}^{-}}+A{{g}^{+}}\underset{CC{{L}_{4}}}{\overset{C{{l}_{2}}}{\mathop \to }}\,R-Br+AgBr+C{{O}_{2}}$
This reaction mechanism mainly involves radical intermediates where the formation of the reactive intermediate, the occurrence of decarboxylation to form a pair of diradical, and recombination of reactant which forms the desired product.
Hence, this reaction is possible with chlorine, and also this reaction provides very good yields with alkaline halide containing 2 to 18 carbon atoms.

Hence, the correct answer is both A and B, option C.

Note: The Hunsdieker reaction was first demonstrated in the year 1861 with the preparation of methyl bromide using silver acetate. There are several variations in these reactions where silver (I) carboxylate is exchanged with thallium (I) carboxylate and the carboxylic acid reacts with halide ions of bromide which lead to decarboxylation.