Question

The reaction of a carboxylic acid and thionyl chloride produces an acid chloride plus the gases SO2 and HCl. In the boxes, draw the mechanism arrows for the reaction. Be sure to add lone pars of electrons and nonzero formal charges on all species.

Answer 1

`S_(N)i` is the major step in forming acid chloride from carboxylic acid and thionyl chloride

Step-by-step explanation:

• In the first step, -OH group in carboxylic acid gives nucleophilic substitution reaction at S center in thionyl chloride and substitutes -Cl atom
• In the second step, deprotonation takes place by chloride ion.
• In the third step, an intramolecular nucleophilic substitution reaction (
  `S_(N)i`) takes place where bond electrons rearranges to produce
  `SO_(2)`, HCl and thionyl chloride.
• This rearrangement is highly favorable due to formation of gaseous species
  `SO_(2)`

• Reaction mechanism has been shown below.