( i ) Reaction with Carboxylic Acids: Alcohols and Phenols react with Carboxylic Acids to form Esters.
This reaction occurs in the presence of concentrated sulfuric acid and it is reversible.
Therefore, the water formed in it is immediately thrown out.
( ii ) Reaction with Acetyl Chloride or Acetic Anhydride (Acetylation)
When a compound containing active hydrogen (H⁺) is reacted with CH₃COCl or (CH₃CO)₂O, and replaced H⁺ by a CH₃CO- group (Acetyl Group). This is called Acetylation.
This reaction with an acid chloride (RCOCI) is carried out in the presence of a base (pyridine).
Due to which HCl formed in this reaction becomes neutral.
So it helps in shifting the equilibrium to the right.
Acetylation of Salicylic Acid yields Aspirin, which is an analgesic, antipyretic and antipyretic.