反应详情

Mg(OCH3)2was prepared as follows: To a 25 mL round-bottom flask under argon was added Mg tunings (90 mg, 3.70 mmol), dry CH3OH (2 mL), 2 drops of CCl4 and a catalytic amount of Mg powder. An exothermic reaction took place and hydrogen gas evolution was observed. After the initial exothermic reaction subsided, the reaction mixture was heated to reflux for 1 hour and then cooled to room temperature. Dimethyl 2-(4-phenoxyphenyl)-2-n-hexylmalonate (500 mg, 1.30 mmol) and urea (162 mg, 2.70 mmol) were added to the Mg(OCH3)2. The reaction mixture was heated at 85-90° C. for 1 hour and then excess CH3OH was distilled off until a fluid-paste was obtained and this paste was then heated at 85-90° C. overnight. The reaction was cooled to room temperature, diluted with EtOAc, and washed with 1N HCl. The acidic aqueous layer was re-extracted with EtOAc. The combined EtOAc extracts were washed with water, brine, dried (MgSO4), and concentrated. The resulting oil was purified with HPLC (porasil) using 30% EtOAc/hexanes as eluent to afford 330 mg of 5-n-hexyl-5-(4-phenoxyphenyl)pyrimidine-2,4,6-trione as a white foam: 1H NMR (400 mHz DMSO-d6) δ 11.71 (2NH, s), 7.42-6.99 (9H, m), 2.22 (2H, t), 1.24 (8H, m), 0.85 (3H, t); HRMS Calcd for C22H24N2O4 380.1736; Found 380.1740.

1. customAn exothermic reaction
2. customAfter the initial exothermic reaction
3. temperaturethe reaction mixture was heated
4. temperatureto reflux for 1 hour
5. temperatureThe reaction mixture was heated at 85-90° C. for 1 hour
6. distillationexcess CH3OH was distilled off until a fluid-paste
7. customwas obtained
8. temperaturethis paste was then heated at 85-90° C. overnight
9. temperatureThe reaction was cooled to room temperature
10. washwashed with 1N HCl
11. extractionThe acidic aqueous layer was re-extracted with EtOAc
12. washThe combined EtOAc extracts were washed with water, brine
13. dry with materialdried (MgSO4)
14. concentrationconcentrated
15. customThe resulting oil was purified with HPLC (porasil)