Using 4-amino-2-oxo-1,2-dihydroquinoline-3-carboxylic acid (CAS: 833461-40-8, 0.030 g, 0.15 mmol) as the raw material, the reaction was heated at 295 °C for 10 min. After completion of the reaction, the mixture was cooled to room temperature to afford 4-aminoquinolin-2(1H)-one (0.023 g, 99% yield), the product was light yellow solid. Melting point: >250 °C. 1H NMR (400 MHz, DMSO-d6) δ 5.42 (s, 1H), 6.55 (s, 2H), 7.07 (t, J = 7.6 Hz, 1H), 7.19 (d, J = 8.0 Hz, 1H), 7.42 (t, J = 7.2 Hz, 1H), 7.86 (d, J = 7.6 Hz, 1H). 10.71 (s, 1H). Mass spectrometry (MS) showed the molecular ion peak m/z 161 (MH+).
