Hydrochloric Acid → 3-(3-Benzylureido)thiophene-2-carboxylic acid

Participants

Reaction Steps

To a solution of methyl 3-amino-thiophene-2-carboxylate 9.43 g (60 mmol) in acetonitrile 12 ml, 2N-sodium hydroxide 36 ml (72 mmol) was added and the mixture was stirred for 5 hrs. at 85° C. The reaction mixture was neutralized with 2N-hydrochloric acid 36 ml (72 mmol), then saturated sodium bicarbonate solution 50 ml and a solution of benzyl isocyanate 7.41 ml (60 mmol) in acetonitrile 36 ml were added and the mixture was stirred overnight. The reaction mixture was basified with 2N-sodium hydroxide 60 ml and washed with ether 100 ml. The aqueous phase was acidified with 2N-hydrochloric acid 85 ml. The aqueous phase was filtered and washed with H2O. The solid was dried in vacuo to obtain the title compound 6.46 g (yield 39%)

Provenance & Evidence