Benzocaine → 4-(Methylsulfonamido)benzoic acid

Participants

Reaction Conditions

Reaction Steps

Ethyl 4-amino-benzoate (5 g, 30 mmol, 1.0 equiv) was mixed in 50 mL of CH2Cl2 with Et3N (6.1 g, 60 mmol, 2.0 equiv). The solution was cooled to 0° C. and methanesulfonyl chloride (3.8 g, 33 mmol. 1.1 equiv) was added as a solution in 15 mL of CH2Cl2 dropwise over a 15 min period. The reaction was stirred for 4 h at which time it was diluted with 50 mL of water. Layers were separated and the organic layer was washed with 50 mL of saturated sodium bicarbonate solution and concentrated. The resulting ester was dissolved in 50 mL of MeOH and treated with 50 mL of 5 N NaOH for 4 h. The reaction solution was extracted with Et2O and the aqueous layer was acidified to give a white precipitate that was collected by filtration. The solid was dried and used without further purification.

Provenance & Evidence