反应详情

A solution of 1-bromo-3-fluorobenzene (5.00 g, 28.6 mmole) in absolute ether (15 ml) was added dropwise to a suspension of magnesium (694 mg, 28.6 mmole) in absolute ether (10 ml) at such a rate that the ether boiled. After completion of the addition the reaction mixture was stirred for 10 minutes at RT, following which the magnesium had completely dissolved. The reaction solution was cooled in an ice bath and 8-dimethylamino-1,4-dioxa-spiro[4.5]decane-8-carbonitrile (3.00 g, 14.3 mmole) in absolute THF (30 ml) was added dropwise at 10° C. The reaction mixture was stirred at room temperature overnight, 20% NH4Cl-solution (20 ml) and water (30 ml) were added thereto while cooling with ice, and the mixture was extracted with ether (3×50 ml). The organic phase was washed with water (50 ml) and then with saturated NaCl solution (50 ml), dried over Na2SO4 and concentrated by evaporation in vacuo. The crude product was dissolved in ethyl methyl ketone (25 ml), ClSiMe3 (3.2 ml, 25 mmole) was added while cooling with ice, and the mixture was stirred at room temperature for 5 hours. The precipitate formed was filtered off and dried in vacuo.

1. additionAfter completion of the addition the reaction mixture
2. dissolutionhad completely dissolved
3. temperatureThe reaction solution was cooled in an ice bath
4. stirringThe reaction mixture was stirred at room temperature overnight
5. temperaturewhile cooling with ice
6. extractionthe mixture was extracted with ether (3×50 ml)
7. washThe organic phase was washed with water (50 ml)
8. dry with materialwith saturated NaCl solution (50 ml), dried over Na2SO4
9. concentrationconcentrated by evaporation in vacuo
10. dissolutionThe crude product was dissolved in ethyl methyl ketone (25 ml)
11. temperaturewhile cooling with ice
12. stirringthe mixture was stirred at room temperature for 5 hours
13. customThe precipitate formed
14. filtrationwas filtered off
15. customdried in vacuo