반응 #56884

반응 방정식

hydrochloric acid

2-bromo-4-chloro-1-(2,2,2-trifluoro-ethoxy)-benzene

isopropylmagnesium chloride

trimethylborate

→

5-chloro-2-(2,2,2-trifluoro-ethoxy)-phenylboronic acid

수율 61.0%

용매

tetrahydrofuran

tetrahydrofuran

반응 조건

후처리

1. 1
   온도After warming to 0° C.
2. 2
   온도After cooling to −70° C.
3. 3
   workup.STIRRINGAfter stirring at room temperature for 12 hours
4. 4
   workup.STIRRINGAfter stirring for 40 minutes
5. 5
   추출the mixture was extracted with ethyl acetate (2×50 ml)
6. 6
   건조The combined extracts were dried over magnesium sulfate
7. 7
   농축concentrated under reduced pressure
8. 8
   기타The residue was triturated with hexane (50 ml)
9. 9
   여과Filtration
10. 10
    기타drying of the solid under reduced pressure

실험 절차

To a mixture of 2-bromo-4-chloro-1-(2,2,2-trifluoro-ethoxy)-benzene (3.0 g, 10.4 mmol) and tetrahydrofuran (60 ml), cooled to −70° C., was added a solution of isopropylmagnesium chloride in tetrahydrofuran (2 M, 5.7 ml). After warming to 0° C., the mixture was stirred for 1 hour. After cooling to −70° C., the mixture was treated with trimethylborate (1.2 g, 11.4 mmol). After stirring at room temperature for 12 hours, the mixture was treated with hydrochloric acid (2 M, 20 ml). After stirring for 40 minutes, the mixture was extracted with ethyl acetate (2×50 ml). The combined extracts were dried over magnesium sulfate and concentrated under reduced pressure. The residue was triturated with hexane (50 ml). Filtration and drying of the solid under reduced pressure gave 5-chloro-2-(2,2,2-trifluoro-ethoxy)-phenylboronic acid (1.6 g, 61% yield). 1H NMR (acetone-d6) δ 4.86 (q, 2H, J=8.5 Hz, CH2), 7.12 (d, 2H, J=4.6 Hz, OH), 7.20 (d, 1H, J=8.8 Hz, Ar), 7.49 (dd, 1H, J=8.8 Hz, J=2.8 Hz, Ar), 7.76 (d, 1H, J—2.7 Hz, Ar).

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