HVZ reaction
Carboxylic Acids and Derivatives · Chemistry
Study notes
Convert CH₃COOH to ClCH₂COOH. Why won't Cl₂ alone work? Step 1: Carboxylic acids enolize poorly — direct α-halogenation is very slow. Step 2: Red P + Cl₂ → PCl₃ in situ → converts RCOOH → RCOCl. Step 3: Acid chlorides enolize readily → α-chlorination fast. Step 4: Hydrolysis → ClCH₂COOH. Red P is the enabler — HVZ needs it!