20. Carboxylic Acid Derivatives:NAS
Carboxylic Acid to Acid Chloride
3PRACTICE PROBLEM
Draw the mechanism for the reaction of 3-methylbutanoic acid and oxalyl chloride to form 3-methylbutanoyl chloride. The mechanism is similar to that of the reaction of thionyl chloride (SOCl2) with a carboxylic acid. It starts with the formation of a mixed acid anhydride intermediate. This anhydride undergoes nucleophilic acyl substitution by the chloride ion, to remove the leaving group which further breaks into carbon dioxide, carbon monoxide, and chloride ion.
Draw the mechanism for the reaction of 3-methylbutanoic acid and oxalyl chloride to form 3-methylbutanoyl chloride. The mechanism is similar to that of the reaction of thionyl chloride (SOCl2) with a carboxylic acid. It starts with the formation of a mixed acid anhydride intermediate. This anhydride undergoes nucleophilic acyl substitution by the chloride ion, to remove the leaving group which further breaks into carbon dioxide, carbon monoxide, and chloride ion.