The reagent which does not give acid chloride on treating with a carboxylic acid is

Options

A. `PCl_(5)`
B. `Cl_(2)`
C. `SOCl_(2)`
D. `PCl_(5)`

Answer

B

Explanation

`PCl_(3) , PCl_(5) and SOCl_(2)` are used to replace3 -OH group of an alcohol or an acid by -Cl group
`R-overset(O)overset(||)C-OH+PCl_(5) to R-overset(O)overset(||)C-Cl+POCl_(3)+HCl`
`R-overset(O)overset(||)C-OH+SOCl_(2) to R-overset(O)overset(||)C-Cl+SO_(2)+HCl`
When acid react with `Cl_(2)` in the presence of red phosphorus, `alpha`-chloroacid is obtained.
(Hell. volharzd-Zelinsky reaction).
`CH_(3)CH_(2)COOH+Cl_(2) overset("Red P") underset(Delta)tounderset(alpha-"chloropropioni acid") overset(Cl) overset(|)(CH_(3)CHCOOH)+HCl`