Acetic Acid → Methyl 4-amino-5-cyanothiophene-2-carboxylate

Participants

Reaction Steps

A suspension of methyl 5-cyano-4-nitro-thiophene-2-carboxylate (0.17 mol, 36 g) and iron powder (0.51 mol, 28.5 g) in glacial acetic acid 68 mL (1.2 mol) was refluxed for 3 hours. The crude was concentrated under vacuum and neutralized with diluted ammonia. The aqueous layer was extracted with ethyl acetate (3×250 mL) and dried over Na2SO4. The filtrate was evaporated to dryness to give a yellow solid, which was purified by flash chromatography over silica gel using hexane/ethyl acetate (38:12) as eluent, to afford the title compound as a yellow solid (21.4 g, 69%).

Provenance & Evidence