Nitronium tetrafluoroborate → 4-(2-Bromo-1,1,2,2-tetrafluoroethylthio)-3,5-dichloronitrobenzene

Temperature

100 °C

A stirred mixture of 30.5 g (0.085 mole) 2-(2-bromo-1,1,2,2-tetrafluoroethylthio)-1,3-dichlorobenzene and 13.3 g (0.10 mole) nitronium tetrafluoroborate (0.5M in sulfone) was heated at 100° C. for approximately 18 hours. An additional 4.0 g of nitronium tetrafluoroborate (solid) was added to the reaction mixture and heating was continued for 14 hours. The mixture was cooled and poured into 200 g of ice water. The resultant mixture was extracted with four 100 ml portions of methylene chloride and the extracts were combined. The organic extract was extracted with three 100 ml portions of a 2N sodium hydroxide solution. The basic aqueous extracts were combined and washed with 100 ml of methylene chloride. The washed extract was made acidic with concentrated hydrochloric acid while cooling in an ice bath. The acidic solution was saturated with sodium chloride and then was extracted with three 150 ml portions of methylene chloride. The organic extracts were combined and dried over anhydrous magnesium sulfate. After filtering the filtrate was evaporated under reduced pressure to leave an oil. This oil was subjected to column chromatography on silica gel, elution with n-heptane, to leave an oil after combining and evaporating the appropriate fractions. This oil was dissolved in n-heptane, leaving a small amount of solid which was removed by filtration. The filtrate was reduced in volume by evaporation under reduced pressure. An oil separated from the n-heptane solution and was removed by pipette. This oil (20.4 g) was found to be unreacted 1-(2-bromo-1,1,2,2-tetrafluoroethylthio)-2,6-dichlorobenzene. The remaining n-heptane was evaporated under reduced pressure to leave 13.3 g of 4-(2-bromo-1,1,2,2-tetrafluoroethylthio)-3,5-dichloronitrobenzene as an oil.

1. temperatureheating
2. temperatureThe mixture was cooled
3. extractionThe resultant mixture was extracted with four 100 ml portions of methylene chloride
4. extractionThe organic extract
5. extractionwas extracted with three 100 ml portions of a 2N sodium hydroxide solution
6. washwashed with 100 ml of methylene chloride
7. extractionThe washed extract
8. temperaturewhile cooling in an ice bath
9. extractionwas extracted with three 150 ml portions of methylene chloride
10. dry with materialdried over anhydrous magnesium sulfate
11. filtrationAfter filtering the filtrate
12. customwas evaporated under reduced pressure
13. customto leave an oil
14. washThis oil was subjected to column chromatography on silica gel, elution with n-heptane
15. customto leave an oil
16. customevaporating the appropriate fractions
17. dissolutionThis oil was dissolved in n-heptane
18. customleaving a small amount of solid which
19. customwas removed by filtration
20. customThe filtrate was reduced in volume by evaporation under reduced pressure
21. customAn oil separated from the n-heptane solution
22. customwas removed by pipette
23. customThe remaining n-heptane was evaporated under reduced pressure

ORD record

ord-fb4187a6a2694840bee0fd6f470204d5

Source dataset

uspto-grants-1987_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04636523