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HuagongsheHuagongshe Chemistry Print Report · For research reference only
HRID 2167731Generated: November 1, 2026

1,2-Dibromoethane → 7-Fluoro-5-nitro-2,3-dihydrobenzo[b][1,4]dioxine

https://huagongshe.com/reaction/2167731

Reaction equation

Participants

RoleNameHCIDCharge
Reactant1,2-DibromoethaneHCID 7839—
ReactantPotassium CarbonateHCID 11430—
Reactant5-Fluoro-3-nitrobenzene-1,2-diolHCID 68816370—
SolventDimethylformamideHCID 6228—
SolventEthyl AcetateHCID 8857—
Product7-Fluoro-5-nitro-2,3-dihydrobenzo[b][1,4]dioxineHCID 68817150—

Reaction Steps

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).

Provenance & Evidence

DOI10.6084/m9.figshare.5104873.v1
Patent numberUS09045478B2
Source datasetuspto-grants-2015_06
ORD IDord-86495fda2f3741e191132791a323e774
Source noteuspto-grants-2015_06