SOCl₂: Converting Carboxylic Acids to Acid Chlorides (Nucleophilic Acyl Substitution)

Learn how SOCl2 converts carboxylic acids into acid chlorides. Mechanism, why gases drive it forward, and how to use acyl chlorides in synthesis.

• Reaction: RCO2H → RCOCl
• What it does: Activates acids for acyl substitution (amides/esters/anhydrides)
• Typical reagents: SOCl2 (± DMF cat.)
• Key intermediate: Acyl chlorosulfite-like activated species; tetrahedral intermediate
• Driving force: SO2(g) + HCl(g) byproducts
• Exam type: Synthesis planning
• Exam type: Acyl substitution