Water → 5-Nitro-2,3-dihydro-1,4-benzodioxine

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Reaction Conditions

Reaction Steps

To a solution of 3-nitrobenzene-1,2-diol (11 g, 0.071 mol) in N,N′-dimethylformamide (500 mL) was added potassium carbonate (29 g, 0.0.213 mol) followed by 1,2-dibromoethane (14.7 g, 0.078 mol). The mixture was heated at 110° C. for 2 hours. After cooled to room temperature, the mixture was poured into water and then extracted with ether. The organic phases were combined and dried over anhydrous sodium sulfate, filtrated and concentrated to give a crude product, which was purified by silica gel column chromatography (petroleum ether/ethyl acetate 20/1) to afford the product 5-nitro-2,3-dihydrobenzo[b][1,4]dioxine (8 g, yield 62%). 1H NMR (400 MHz, CDCl3) δ ppm 7.48-7.50 (dd, 1H, J=1.6 Hz, 8.4 Hz), 7.09-7.12 (dd, 1H, J=1.6 Hz, 8.4 Hz), 6.88-6.92 (t, 1H, J=8.4 Hz), 4.40-4.42 (m, 2H), 4.34-4.36 (m, 2H).

Provenance & Evidence