General procedure for the synthesis of N-(2-hydroxyethyl)-3-oxobutanamide from bis(vinylidene) ketone and 2-aminoethanol: 23 mL (0.38 mol) of 2-aminoethanol was added slowly and dropwise to 30 g (0.36 mol) of bis(vinylidene) ketone dissolved in 300 mL of tetrahydrofuran at -5 to 0 °C. The reaction mixture was stirred at 0 °C for 1 h. Complete consumption of the feedstock was confirmed by thin layer chromatography (TLC) monitoring. Subsequently, the solvent was removed by evaporation and the residue was purified by column chromatography. Finally, 41.44 g (0.29 mol, 80% yield) of the target compound was obtained as a white solid. The product was identified by infrared spectroscopy (IR, neat, cm?1) showing characteristic absorption peaks: 3273, 3097, 2973, 2938, 2880, 1710, 1646, 1558, 1494, 1465, 1420, 1362, 1347, 1312, 1297, 1215, 1190, 1166, 1052, 1038. (2H), 3.4 (4H), 2.2 (3H).
