반응 #2075726

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DMF

1-Bromo-4-chloro-2-fluoro-3-methoxybenzene

n-Butyllithium

→

title compound

수율 61.0%

4-Chloro-2-fluoro-3-methoxybenzaldehyde

수율 61.0%

용매

diethyl ether

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후처리

1. 1
   기타7,300,907 for preparation)
2. 2
   기타the temperature below −70° C.
3. 3
   workup.ADDITIONduring the addition
4. 4
   기타the temperature below −60° C
5. 5
   온도to warm to ambient temperature
6. 6
   기타quenched with water
7. 7
   기타The organic phase was dried
8. 8
   농축concentrated
9. 9
   기타The product was purified by flash chromatography on silica gel (hexane/ethyl acetate gradient)

실험 절차

1-Bromo-4-chloro-2-fluoro-3-methoxybenzene (23.7 g, 99 mmol, see U.S. Pat. No. 7,300,907 for preparation) was dissolved in dry diethyl ether and cooled to −78° C. 2.5M n-Butyllithium in hexanes (44 mL, 110 mmol) was added in portions, keeping the temperature below −70° C. during the addition. DMF (15.5 mL, 200 mmol) was then added in portions, keeping the temperature below −60° C. The reaction mixture was then allowed to warm to ambient temperature and quenched with water. The organic phase was dried and concentrated. The product was purified by flash chromatography on silica gel (hexane/ethyl acetate gradient) to yield the title compound in sufficient purity for subsequent reactions (11.4 g, 61% yield): 1H NMR (CDCl3) δ 10.32 (s, 1H), 7.55 (m, 1H), 7.3 (m, 1H), 4.05 (d, 3H).

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