Acetic Acid → 4-(((5-Chloro-2thienyl)methyl)amino)-benzoic acid

Participants

Reaction Conditions

Reaction Steps

A mixture containing 46.6 grams (0.34 moles) of p-aminobenzoic acid, 50 grams (0.34 moles) of 5-chloro-2-thiophenecarboxaldehyde and 400 ml. of toluene was heated to reflux for about three and a half hours. The water formed was collected in a Dean-Stark trap. The reaction mass was cooled at the end of this period and the Schiff base collected as a tan solid. To a mixture of the intermediate Schiff base and 1.2 liters of glacial acetic acid 21.2 grams (0.36 moles) of dimethylaminoborane was added. The reaction mass was warmed to 40° C. for about 30 minutes and poured in 2 liters of ice water. The white precipitate of 4-(((5-chloro-2-thienyl)methyl)amino)benzoic acid was washed in water, dried, and recrystallized from toluene. The melting point was 177°-178° C.

Provenance & Evidence