Methyl 2-Amino-5,6-dihydro-4H-cyclopenta[b]thiophene-3-carboxylate

To a mixture contaning cyclopentanone (8.49 g, 0.1 mol), methyl cyanoacetate (10.0 g, 0.1 mol) and sulfur (3.21 g, 0.1 mol) in methanol (20 ml), morpholine (10 ml) was added dropwise over a period of 30 minutes at 35 °C.[...]