Synthesis
General procedure for the synthesis of 7-amino-3,4-dihydro-2(1H)-quinolinone from the compound (CAS: 1613720-64-1): firstly, a suspension of Pd(OH)2/C (10%, 3.0 g) and ethyl (E)-3-(2,4-dinitrophenyl)acrylate (12.0 g, 45.1 mmol) in MeOH (80 mL) was was stirred at 25°C. The reaction was carried out under H2 (45 psi) atmosphere for 15 hours. Upon completion of the reaction, the mixture was filtered and the filtrate was concentrated under vacuum to afford ethyl 3-(2,4-diaminophenyl)propionate (8.6 g, 98% yield), which was used directly in the next step of the reaction without further purification. Next, a solution of EtOH (50 mL) of ethyl 3-(2,4-diaminophenyl)propanoate (8.6 g, 41.3 mmol) was stirred at 85-100°C for 48 hours. At the end of the reaction, the reaction mixture was cooled to room temperature and the solvent was removed under vacuum. EtOAc (10 mL) was added to the residue and the precipitate was collected by filtration to afford 7-amino-3,4-dihydro-1H-quinolin-2-one (5.8 g, 87% yield). The product was characterized by 1H NMR (DMSO-d6, 400 MHz): δ 9.83 (brs, 1H), 6.76 (d, J = 7.6 Hz, 1H), 6.12 (m, 2H), 4.95 (brs, 2H), 2.65 (t, J = 7.2 Hz, 2H), 2.36 (t, J = 7.2 Hz, 2H).
