反应详情

K2CO3 (15.27 g, 110.6 mmol) was added to a solution of 5-fluoro-3-nitrobenzene-1,2-diol (5 g, 28.9 mmol) in DMF (35 mL) followed by the addition of 1,2-Dibromoethane (13.63 g, 6.25 mL, 72.5 mmol) and stirring was continued at 80° C. for 2 h. Reaction mixture was diluted with ethyl acetate, washed with cold water, dried over anhydrous sodium sulphate and concentrated under reduced pressure to afford the crude, which was purified by MPLC (silica gel, Mobile Phase: ethyl acetate in n-Hexane 0 to 5% as eluant) to afford 7-fluoro-5-nitro-2,3-dihydrobenzo[b][1,4]dioxine (Int-51) as pale yellow solid. 1H NMR (300 MHz, CDCl3) δ ppm 7.3-7.2 (1H, dd), 6.9-6.8 (1H, dd), 4.4 (4H, s).

1. customReaction mixture
2. washwashed with cold water
3. dry with materialdried over anhydrous sodium sulphate
4. concentrationconcentrated under reduced pressure
5. customto afford the crude, which
6. customwas purified by MPLC (silica gel, Mobile Phase: ethyl acetate in n-Hexane 0 to 5% as eluant)