Potassium Carbonate → HCID 178463117, compound

Temperature

90 °C

Thionyl chloride (3.5 g, 6.7 mmol) was added to a slurry of 1.3 g (4.8 mmol) of 2,3-dichloro-4-methylsulfonylbenzoic acid in 10 mL of toluene with stirring and the mixture was heated at reflux until a homogeneous solution was obtained, which required about 45 min. The volatile components of the mixture were removed by evaporation under reduced pressure and the residual acid chloride was taken up in 10 mL of dichloromethane. This solution was combined with a solution of 5.4 g (4.8 mmol) of 1-ethyl-5-hydroxypyrazole dissolved in 6.2 mL of 1 N aqueous sodium hydroxide solution diluted with 5 mL of water with stirring at ambient temperature. After 1 hour, the pH was adjusted to 8 by adding 1 M aqueous sodium bicarbonate. The phases present were separated and the aqueous phase was extracted with 3 mL of dichloromethane. The organic phase and extract were combined, washed with 5 mL of water, dried over sodium sulfate, filtered, and concentrated by evaporation under reduced pressure. The residue was taken up in 15 mL of anhydrous dioxane and 730 mg (5.3 mmol) of solid potassium carbonate was added. The mixture was heated at 90° C. with stirring for 2 hours and then another 100 mg of potassium carbonate and 2-3 drops of acetone cyanohydrin were added. Heating and stirring were continued for another 30 min and then the mixture was cooled and poured into 15 mL of water. The phases were separated and the aqueous phase was extracted with 2×5 mL of dichloromethane. The aqueous phase was then acidified with 6 N aqueous hydrochloric acid and the solids that formed were extracted with 2×5 mL of dichloromethane. All of the organic phases and extracts were combined, washed with 5 mL of water, dried over sodium sulfate, filtered, and concentrated by evaporation under reduced pressure. The residue, which amounted to 1.4 g (80 percent of theory), was recrystallized from aqueous ethanol to obtain the title compound as a white solid melting at 198-200° C.

1. temperaturethe mixture was heated
2. temperatureat reflux until a homogeneous solution
3. customwas obtained
4. customabout 45 min
5. customThe volatile components of the mixture were removed by evaporation under reduced pressure
6. stirringwith stirring at ambient temperature
7. customThe phases present were separated
8. extractionthe aqueous phase was extracted with 3 mL of dichloromethane
9. extractionThe organic phase and extract
10. washwashed with 5 mL of water
11. dry with materialdried over sodium sulfate
12. filtrationfiltered
13. concentrationconcentrated by evaporation under reduced pressure
14. stirringwith stirring for 2 hours
15. temperatureHeating
16. stirringstirring
17. waitwere continued for another 30 min
18. temperaturethe mixture was cooled
19. customThe phases were separated
20. extractionthe aqueous phase was extracted with 2×5 mL of dichloromethane
21. customthe solids that formed
22. extractionwere extracted with 2×5 mL of dichloromethane
23. washwashed with 5 mL of water
24. dry with materialdried over sodium sulfate
25. filtrationfiltered
26. concentrationconcentrated by evaporation under reduced pressure
27. customwas recrystallized from aqueous ethanol

ORD record

ord-0e0b69f55bba4c06858a52030a3f61b0

Source dataset

uspto-grants-2001_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06211403B1