反应详情

A procedure similar to that described in Bull. Chem. Soc. Japan, 59, 3285–3286 (1986), fully incorporated herein by reference, was used. In a two liter round bottom flask equipped with an overhead stirrer and heating mantle was placed 2-bromo-meta-xylene (60.08 g, 0.325 mol) and carbon tetrachloride (650 ml). To this were added N-bromosuccinimide (57.78 g, 0.325 mol) and an additional 550 ml carbon tetrachloride. After stirring fifteen minutes benzoyl peroxide (0.72 g, 2.9 mmol, 0.9 mole %) was added, and the mixture was heated to reflux. After four hours the reaction was cooled, and the carbon tetrachloride was removed. The residue was taken up in 10% methylene chloride in n-hexane (600 ml) and filtered through silica (250 g). The filter cake was washed with an additional 400 ml of the in 10% methylene chloride in n-hexane. The filtrate was evaporated to give a clear liquid (74.22 g, 51% conversion by NMR). Vacuum distillation produced a fraction distilling at 72° C.–80° C. at 0.1 Torr as a water white liquid (40.62 g, 47% yield). NMR (CD2Cl2). 7.2 (m, 3H), 4.62 (s, 2H), 2.4 (s, 3H). Elemental analysis: C, 36.18%; H, 3.12%; Br, 61.14%; (theory: C, 36.40%; H, 3.06%; Br, 60.54%).

1. customIn a two liter round bottom flask equipped with an overhead stirrer
2. temperatureheating mantle
3. additionwas added
4. temperaturethe mixture was heated to reflux
5. temperatureAfter four hours the reaction was cooled
6. customthe carbon tetrachloride was removed
7. filtrationfiltered through silica (250 g)
8. washThe filter cake was washed with an additional 400 ml of the in 10% methylene chloride in n-hexane
9. customThe filtrate was evaporated
10. customto give a clear liquid (74.22 g, 51% conversion by NMR)
11. distillationVacuum distillation
12. customproduced a fraction