反应详情

A solution of 5-(5-bromopyridin-2(1H)-ylidene)-2,2-dimethyl-1,3-dioxane-4,6-dione (3) (40.0 g, 133.3 mmol) in HCl (30%, 400 mL) was heated gently to reflux, and was refluxed for 2 h. The solvent was removed in vacuo and the residue (29.75 g) was used in the next step without further purification. 1H-NMR (CDCl3, 300 MHz): δ 3.79 (s, 2H, CH2), 7.41 (d, 1H, ArH), 8.08 (dd, 1H, ArH), 8.66 (d, 1H, ArH).

1. temperatureto reflux
2. temperaturewas refluxed for 2 h
3. customThe solvent was removed in vacuo
4. customthe residue (29.75 g) was used in the next step without further purification