反应详情

198.1 ml (3.85 mol) of bromine were added dropwise at -5° to 0° C. to a solution of 470 g of sodium hydroxide in 2 l of water. The mixture was stirred at this temperature for a further 10 min. The resulting sodium hypobromite solution was added dropwise at -5° to 0° C. to a solution of 464 g of a 40% strength aqueous dimethylamine solution (4.11 mol) in 50 ml of water. The mixture was stirred for a further 30 min, the organic phase was then separated off and the aqueous phase was extracted twice using 750 ml of methylene chloride each time. The combined organic phases were dried briefly over magnesium sulfate and filtered. The filtrate was added dropwise at -10° C. to a solution of 500 g (3.67 mol) of ortho-isopropylphenol in 900 ml of methylene chloride. After adding about 2/3 of the filtrate, a solid formed and the reaction mixture became viscous and could only be stirred with difficulty. 500 ml of methylene chloride were added at -10° C. and the mixture was stirred for a further hour. The solid was filtered off with suction, washed with a little cold methylene chloride, suspended in 1.5 1 of 2N sulfuric acid and stirred at room temperature until all the solid had been converted into an oil. The organic phase was separated off, and the aqueous phase was extracted using methylene chloride. The combined organic phases were washed with sodium chloride solution and dried, and the solvent was removed in vacuo. The residue was distilled through a 30 cm Vigreux column in a water jet vacuum.

1. stirringThe mixture was stirred for a further 30 min
2. customthe organic phase was then separated off
3. extractionthe aqueous phase was extracted twice
4. dry with materialThe combined organic phases were dried briefly over magnesium sulfate
5. filtrationfiltered
6. additionAfter adding about 2/3 of the filtrate
7. customa solid formed
8. stirringcould only be stirred with difficulty
9. stirringthe mixture was stirred for a further hour
10. filtrationThe solid was filtered off with suction
11. washwashed with a little cold methylene chloride
12. stirringstirred at room temperature until all the solid
13. customThe organic phase was separated off
14. extractionthe aqueous phase was extracted
15. washThe combined organic phases were washed with sodium chloride solution
16. customdried
17. customthe solvent was removed in vacuo
18. distillationThe residue was distilled through a 30 cm Vigreux column in a water jet vacuum