Sulfonated polypyrene (S-PPR) as efficient catalyst for esterification of carboxylic acids with equimolar amounts of alcohols without removing water

Sulfonated polypyrene (S-PPR) efficiently catalyzed the reactions between carboxylic acids and equimolar amounts of alcohols with and without heptane to give the corresponding esters in good to excellent yields. Esterification was carried out at 110 °C without removing water. Transesterification of carboxylic esters with a slight excess of alcohols smoothly proceeded without heptane to give the corresponding esters in good yields. For these reactions, S-PPR was recycled without significant loss of activities.