Ethyl 5-nitro-1-benzothiophene-2-carboxylate → Ethyl 5-amino-1-benzothiophene-2-carboxylate

Participants

Reaction Steps

A suspension of 5-nitro-benzo[b]thiophene-2-carboxylic acid ethyl ester (10.52 g, 41.89 mmol) and 10% Pd/C (1.1 g) in 450 mL of EtOH was hydrogenated under 1 atm of H2 for 4 d at rt. The reaction mixture was filtered and the filtrate was concentrated and dried to give 5-amino-benzo[b]thiophene-2-carboxylic acid ethyl ester as a green solid. A parallel reaction was preformed on 10.61 g of 5-nitro-benzo[b]thiophene-2-carboxylic acid ethyl ester in the same manner. A total of 18.37 g of 5-amino-benzo[b]thiophene-2-carboxylic acid ethyl ester was obtained. MS (EI): cal'd 222.0 (MH+), exp 222.2 (MH+). Procedure for Acylation

Provenance & Evidence