Reaction #1563947

Reaction equation

K2CO3

5-fluoro-3-nitrobenzene-1,2-diol

1,2-Dibromoethane

→

7-fluoro-5-nitro-2,3-dihydrobenzo[b][1,4]dioxine

Solvents

DMF

ethyl acetate

Conditions

Workup

1. 1
   OtherReaction mixture
2. 2
   Washwashed with cold water
3. 3
   Dryingdried over anhydrous sodium sulphate
4. 4
   Concentrationconcentrated under reduced pressure
5. 5
   Otherto afford the crude, which
6. 6
   Otherwas purified by MPLC (silica gel, Mobile Phase: ethyl acetate in n-Hexane 0 to 5% as eluant)

Procedure

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).

Source