A mixture of 7-(2,5-dimethyl-1H-pyrrol-1-yl)-3,4-dihydroquinolin-2(1H)-one (1.4 g, 5.8 mmol) and potassium carbonate (2.4 g, 17.5 mmol) in ACN (40 mL) was stirred for 30 min then ethyl 2-bromopropanoate (2.1 g, 11.6 mmol) was added and the mixture was heated to reflux overnight. The reaction mixture was cooled to ambient temperature and the solvent was removed in vacuo. EtOAc (50 mL) and water (30 mL) was added to the residue and the organic layer was separated, dried over anhydrous Na2SO4, filtered and concentrated in vacuo. The residue was purified by column chromatography on silica gel (eluting with 0-30% EtOAc in petroleum ether) to give ethyl 2-(7-(2,5-dimethyl-1H-pyrrol-1-yl)-2-oxo-3,4-dihydroquinolin-1(2H)-yl)propanoate (1.6 g, 81%). 1H NMR (CDCl3, 400 MHz): δ 7.26 (d, J=7.2 Hz, 1H), 6.87 (d, J=7.6 Hz, 1H), 6.71 (s, 1H), 5.91 (s, 2H), 4.98 (q, J=6.8 Hz, 1H), 4.17 (q, J=7.2 Hz, 2H), 2.96 (m, 2H), 2.72 (m, 2H), 2.05 (s, 6H), 1.61 (d, J=7.2 Hz, 3H), 1.19 (t, J=7.2 Hz, 3H).
