Benzocaine → Octadecyl 4-aminobenzoate

Participants

Reaction Conditions

Reaction Steps

A 1-liter round bottom flask was fitted with a reflux condenser, Dean Stark trap and heating mantle and charged with 54 g (0.20 mole) of 1-octadecanol, 33 g (0.20 mole) ethyl 4-aminobenzoate, 8 g of p-toluenesulfonic acid and 500 ml of mixed xylenes. The flask was flushed with nitrogen and sealed under a nitrogen balloon. The reaction system was heated to reflux with a pot temperature of about 140° C. and allowed to reflux for about 1/2 hour before a 25 ml-aliquot of xylenes-ethanol mixture was removed through the Dean-Stark trap. Every 5-10 minutes, another 25 ml aliquot of the xylenes-ethanol mixture was removed until a total of 400 ml had been withdrawn from the reaction mixture and the pot attained a temperature of 150° C. Remaining volatiles were removed under 29 inches of Hg vacuum at 70° C. in a vacuum oven to give 95 g of an off-white waxy material melting at 60°-70° C., with an infrared spectrum showing the amino-aromatic ester with a long-chain aliphatic tail.

Provenance & Evidence