反应详情

4-(4-Bromo-2-cyclopropyl-1-((2-(trimethylsilyl)ethoxy)methyl)-1H-imidazol-5-yl)-2-chloro-4,5-dihydropyrimidine (21.65 g, 50.1 mmol) and manganese dioxide (43.6 g, 501 mmol) in EtOAc (240 mL) was heated at reflux for 2.5 hours. The reaction mixture was cooled to room temperature and filtered through Celite. The filtrates were concentrated and the residue purified by flash column chromatography (10-40% EtOAc in heptane) to afford 4-(4-bromo-2-cyclopropyl-1-((2-(trimethylsilyl)ethoxy)methyl)-1H-imidazol-5-yl)-2-chloropyrimidine as a yellow oil (17.8 g, 41.4 mmol, 83%). LCMS(m/z) 429.0 (MH+), tR=1.24 minutes; 1H NMR (400 MHz, CDCl3) δ-0.06 (s, 9H), 0.82-0.90 (m, 2H), 1.04-1.11 (m, 2H), 1.14-1.20 (m, 2H), 2.06 (m, 1H), 3.55-3.62 (m, 2H), 5.92 (s, 2H), 7.92 (d, J=5.5 Hz, 1H), 8.62 (d, J=5.5 Hz, 1H).

1. temperatureat reflux for 2.5 hours
2. filtrationfiltered through Celite
3. concentrationThe filtrates were concentrated
4. customthe residue purified by flash column chromatography (10-40% EtOAc in heptane)