Method A: Synthesis of amide analogs (4). Synthesis of N-[2-(dimethylamino)ethyl]-12-oxo-12H-benzo[g]pyrido[2,1-b]quinazoline-4-carboxamide. 12-Oxo-12H-benzo[g]pyrido[2,1-b]quinazoline-4-carboxylic acid (50 mg, 0.17 mmol) and TBTU (82.9 mg, 0.26 mmol) were dissolved in DMF (1 mL) and DbEA (90 μL, 0.52 mmol) was added. After stirring for 15 min at room temperature, N,N-dimethylethylenediamine (28.4 μL, 0.26 mmol) was added and stirring was continued for 16 hours. The reaction mixture was poured into 100 mL of cold water with stirring, and the solid was collected by filtration and dried under vacuum to afford the target product N-[2-(dimethylamino)ethyl]-12-oxo-12H-benzo[g]pyrido[2,1-b]quinazoline-4-carboxamide (36 mg, 0.10 mmol, 58.0% yield) as a yellow solid.1H NMR (400 MHz , DMSO-d6) δ ppm 11.50 (br.s, 1H), 9.10 (s, 1H), 8.91 (d, J=5.81 Hz, 1H), 8.55 (d, J=5.56 Hz, 1H), 8.28-8.34 (m, 2H), 8.12 (d, J=8.34 Hz, 1H), 7.73 (t, J=7.45 Hz , 1H), 7.61 (t, J=7.33 Hz, 1H), 7.05 (t, J=7.07 Hz, 1H), 3.56 (d, J=5.05 Hz, 2H), 2.59 (t, J=5.94 Hz, 2H), 2.40 (s, 6H).1H NMR (400 MHz, CDCl3) δ ppm 11.70 (br.s. 1H), 9.10 (s, 1H), 8.94 (dd, J=7.33,1.77 Hz, 1H), 8.73 (dd, J=6.82,1.77 Hz, 1H), 8.29 (s, 1H), 8.12 (d, J=8.59 Hz, 1H), 8.00 (d, J=8.34 Hz, 1H), 7.66 (t, J= 7.58 Hz, 1H), 7.52-7.60 (m, 1H), 6.89 (t, J=7.07 Hz, 1H), 3.66-3.77 (m, 2H), 2.71 (t, J=6.06 Hz, 2H), 2.49 (s, 6H). ms [M+1]=361.
![12-oxo-12H-benzo[g]pyrido[2,1-b]quinazoline-4-carboxylic acid](/CAS2/GIF/63127-04-8.gif)
