Hydrochloric Acid → 4-(3-ethoxy-4-hydroxy-5-nitrophenyl)-6-phenyl-5-(thiazol-2-yl)-3,4-dihydropyrimidin-2(1H)-one

Participants

Reaction Steps

To a mixture of 1-phenyl-2-(thiazol-2-yl)ethanone (Intermediate 3) (170 mg, 0.84 mmol), 3-ethoxy-4-hydroxy-5-nitrobenzaldehyde (212 mg, 1.00 mmol), and urea (151 mg, 2.52 mmol) in anhydrous EtOH (20 mL) was added concentrated HCl solution (0.1 mL), and the reaction mixture was refluxed for three days. When TLC (EtOAc:MeOH=10:1) showed that about 30% of the starting materials were consumed, the reaction mixture was concentrated, and the crude product was purified by column chromatography and preparative HPLC to afford Compound 12 as a yellow solid (12.5 mg, yield: 3.4%). 1H NMR (DMSO-d6 400 MHz TMS): δ 10.25 (s, 1H), 9.25 (s, 1H), 7.82 (s, 1H), 7.50-7.56 (m, 4H), 7.48 (s, 1H), 7.36-7.40 (m, 3H), 7.22 (d, J=3.6 Hz, 1H), 5.68 (d, J=3.6 Hz, 1H), 4.10 (q, J=6.0 Hz, 2H), 1.35 (t, J=7.2 Hz, 3H); MS (ESI): m/z 439.1 [M+1]+.

Provenance & Evidence