Question

In the following reaction
$ RCH_{2}COOH \ce{ ->[Br_{2}/p] } X \ce{ ->[excess NH_{3}] } Y $
The major amounts of $ X $ and $ Y $ are

• A. $ RCHBrCONH_{2} ; RCH(NH_{2} )COOH $
• B. $ RCHBrCOOH ; RCH(NH_{2} )COOH $
• C. $ RCH_{2}COBr ; RCH_{2}COONH_{4} $
• D. $ RCHBr COOH ; RCH_{2}CONH_{2} $

Answer 1

Answer: (B)

When an acid is heated with $Br_{2}$ in presence of $P, \alpha-H$ atom of the acid is replaced by bromine atom. This reaction is called Hell-Volhard Zelinsky reaction. $NH^{-}_{2}$ is a better nucleophile than $Br^{-}$