反应详情

温度

-78 °C

At room temperature, 2.0 g (22.4 mmol) of N,N-dimethylaminoethanol were added to 2.0 g (6.4 mmol) of 3-(2-chloro-6-fluorophenyl)-2,4,6-trichloropyridine (see Example Ab) dissolved in 25 ml of tetrahydrofuran, and the mixture was cooled to −78° C. 26 ml (41.9 mmol) of n-butyllithium (1.6 M in hexane) were then added dropwise, and the mixture was stirred at −75° C. to −50° C. for 1.5 h. 4.0 g (15.4 mmol) of 1,2-dibromotetra-fluoroethane were then added dropwise, and the mixture was stirred at −50° C. to −70° C. for 1 h, thawed to room temperature, added to 70 ml of 10% strength hydrochloric acid, extracted three times with in each case 80 ml of methyl tert-butyl ether, dried over sodium sulfate, concentrated under reduced pressure and triturated with hexane. Yield 1.6 g. 1H-NMR (CDCl3) δ=7.15 (m); 7.40 (m).

1. stirringthe mixture was stirred at −50° C. to −70° C. for 1 h
2. extractionextracted three times with in each case 80 ml of methyl tert-butyl ether
3. dry with materialdried over sodium sulfate
4. concentrationconcentrated under reduced pressure
5. customtriturated with hexane