反应详情

5-(5-Bromopyridin-2(1H)-ylidene)-2,2-dimethyl-1,3-dioxane-4,6-dione (example 42f) (3.55 g, 11.87 mmol) was suspended in conc. HCl (55 mL) and refluxed for 3 h. The solution was concentrated under reduced pressure and a residue was triturated with EtOH to provide white crystals that were filtered off and washed with EtOH (2.34 g, 78%). 1H NMR (400 MHz, dMSO): δ 3.81 (s, 2H), 7.44-7.46 (d, 1H), 8.12-8.15 (dd, 1H), 8.70-8.71 (d, 1H), 11.30 (bs, 1H); MS+H (218).

1. temperaturerefluxed for 3 h
2. concentrationThe solution was concentrated under reduced pressure
3. customa residue was triturated with EtOH
4. customto provide white crystals that
5. filtrationwere filtered off
6. washwashed with EtOH (2.34 g, 78%)