반응 #171848

반응 방정식

bromine

8-bromo-3,4-dihydro-2H-benzo[b]oxepin-5-one

bromine

→

title compound

수율 97.0%

4,8-Dibromo-3,4-dihydro-2H-benzo[b]oxepin-5-one

수율 97.0%

용매

diethyl ether

반응 조건

후처리

1. 1
   온도to warm up to RT
2. 2
   workup.STIRRINGstirred for 3 h
3. 3
   workup.STIRRINGstirring
4. 4
   workup.WAITwas pursued for 16 h
5. 5
   기타The solvent was removed in vacuo
6. 6
   기타the resultant residue was purified by flash chromatography (SiO2, 10% ethyl acetate in cyclohexane)

실험 절차

To a solution of 8-bromo-3,4-dihydro-2H-benzo[b]oxepin-5-one (1.2 g, 5 mmol) in diethyl ether (20 mL) at 0° C. was added bromine (257 μL, 5 mmol) dropwise under nitrogen. The reaction mixture was stirred at 0° C. for 1 h, allowed to warm up to RT and stirred for 3 h. Further bromine (50 μL, 0.97 mmol) was added and stirring was pursued for 16 h. The solvent was removed in vacuo and the resultant residue was purified by flash chromatography (SiO2, 10% ethyl acetate in cyclohexane) to give the title compound as a white solid (1.55 g, 97%). 1H NMR (CDCl3): 7.62 (1 H, m), 7.26 (2 H, m), 4.94 (1 H, dd, J=7.7, 6.7 Hz), 4.43 (1 H, ddd, J=12.7, 5.6, 4.8 Hz), 4.25-4.15 (1 H, m), 2.97-2.86 (1 H, m), 2.51 (1 H, ddt, J=14.7, 7.7, 4.6 Hz).

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