تفاعل #56884

معادلة التفاعل

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

المردود 61.0%

المذيبات

tetrahydrofuran

tetrahydrofuran

ظروف التفاعل

المعالجة

1. 1
   درجة الحرارةAfter warming to 0° C.
2. 2
   درجة الحرارةAfter 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
   استخلاصthe mixture was extracted with ethyl acetate (2×50 ml)
6. 6
   تجفيفThe combined extracts were dried over magnesium sulfate
7. 7
   تركيزconcentrated under reduced pressure
8. 8
   أخرىThe residue was triturated with hexane (50 ml)
9. 9
   ترشيحFiltration
10. 10
    أخرىdrying of the solid under reduced pressure

الإجراء التجريبي

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).

المصدر