反应详情

温度

-70 °C

n-Butyllithium (42 ml, 2.4M in hexane) was slowly added to a solution of 30.78 g 1,4-dibromo-2,3,5,6-tetrafluorobenzene in 200 ml tetrahydrofuran cooled to -70° C. under nitrogen. Solid carbon dioxide (about 12 g) was then added to the stirred mixture which was then allowed gradually to warm to 0° C. at which point 16 ml 6M hydrochloric acid and 16 ml water were added. The reaction mixture was concentrated and the residue extracted with methylene dichloride. The extract was washed with concentrated sodium chloride solution, dried (magnesium sulfate) and concentrated to dryness to give 22.23 g (81.5%) 4-bromo-2,3,5,6-tetrafluorobenzoic acid, m.p. 128°-135° C.

1. additionwere added
2. concentrationThe reaction mixture was concentrated
3. extractionthe residue extracted with methylene dichloride
4. washThe extract was washed with concentrated sodium chloride solution
5. dry with materialdried (magnesium sulfate)
6. concentrationconcentrated to dryness