2-Ethyl 4-methyl 5-amino-3-methylthiophene-2,4-dicarboxylate

To a mixture contaning ethyl acetoacetate (13.02 g, 0.1 mol), methyl cyanoacetate (3.21 g, 0.1 mol) and sulfur (3.21 g, 0.1 mol) in ethanol ( 20 ml), morpholine (10 ml) was added dropwise over a period of 30 minutes at 35°C.[...]