To a solution of 2-(3,4-difluorophenyl)-1-phenylethanone (Intermediate 12) (150 mg, 0.65 mmol), 3-ethoxy-4-hydroxy-5-nitrobenzaldehyde (128.1 mg, 0.65 mmol), and urea (117 mg, 1.95 mmol) in 20 mL of ethanol was added 0.2 ml con. HCl. The mixture was refluxed for 2 days. After the solvent was removed under reduced pressure, the residue was purified by reverse-phase preparatory HPLC (26-53% acetonitrile+0.1% trifluoroacetic acid in water+0.1% trifluoroacetic acid, over 15 min.) to give Compound 30 (132 mg, yield 43.3%). 1H NMR (DMSO-d6 400 MHz): δ 10.30 (s, 1H), 8.82 (s, 1H), 7.58 (s, 1H), 7.43 (s, 1H), 7.30-7.20 (m, 6H), 7.07 (m, 1H), 6.86 (m, 1H), 6.59 (s, 1H), 5.27 (s, 1H), 4.08 (m, 2H), 1.33 (t, J=6.8 Hz, 3H); MS (ESI): m/z 468.0 [M+1]+
