To a mixture of 2-(5-oxo-2-thioxoimidazolidin-1-yl)-3-phenylpropanoic acid (0.080 g, 0.303 mmol) and 5-(4-methoxylphenyl)thiophene-2-carbaldehyde (0.066 g, 0.303 mmol) in acetic acid 5 mL is added β-alanine (2.69 mg, 0.030 mmol) and heat to 170° C. for 30 min under microwave irradiation. The resulting reaction mixture is cooled down and the solvent is removed. The pure product (0.075 g, 0.162 mmol, red solid) is obtained by column chromatography using MeOH/DCM, 2-7% ration solvent system. 1H-NMR (CD3OD/300 MHz): 7.62 (m, 2H), 7.45 (m, 1H), 7.33 (m, 5H), 7.27 (d, J=13.2 Hz, 1H), 6.94 (d, J=6.9 Hz, 2H), 6.70 (s, 1H), 5.50 (m, 1H), 3.82 (s, 3H), 3.53 (m, 2H). MS (ES+, m/z): 465.1 (M++1, 20.0).
