Acetic Anhydride → HCID 22238056, compound

To a solution of 65% potassium nitrosodisulfonate (14.4 g, 34.9 mmol) in pH 6.86 phosphate buffer (460 mL) was added a solution of 2,3-dihydro-2,2,6,7-tetramethyl-1H-indole (2.91 g, 14.6 mmol) in methanol (80 mL), and the mixture was stirred at room temperature for 15 minutes. The reaction mixture was extracted with ethyl acetate three times, and the combined organic layers were washed with water. This solution was mixed with a solution of sodium hydrosulfite (6.36 g, 36.5 mmol) in water (75 mL), the mixture was shaken, and the aqueous layer was separated. The organic layer was washed with saturated brine, dried over magnesium sulfate, filtered, and concentrated under reduced pressure. The residue was dissolved in formic acid (5 mL), a solution of acetic anhydride (3.2 mL, 34 mmol) in formic acid (5 mL) (which had been stirred at room temperature for 20 minutes in advance) was added dropwise, and the mixture was stirred at room temperature for 1 hour. The reaction mixture was concentrated under reduce pressure, neutralized with an aqueous saturated solution of sodium bicarbonate, and extracted with chloroform three times. The combined organic layers were washed with water, and concentrated under reduced pressure. The residue was dissolved in methanol (30 mL) and chloroform (15 mL), a 1N aqueous solution of sodium hydroxide was added under ice-cooling. and the mixture was stirred at the same temperature for 10 minutes. The reaction mixture was neutralized with 1N hydrochloric acid, and the mixture was extracted with chloroform three times. The combined organic layers were washed with water and saturated brine, dried over magnesium sulfate, filtered, and concentrated under reduced pressure. The residue was recrystallized from ethanol-diisopropyl ether to obtain 1.48 g of the title compound.

1. extractionThe reaction mixture was extracted with ethyl acetate three times
2. washthe combined organic layers were washed with water
3. stirringthe mixture was shaken
4. customthe aqueous layer was separated
5. washThe organic layer was washed with saturated brine
6. dry with materialdried over magnesium sulfate
7. filtrationfiltered
8. concentrationconcentrated under reduced pressure
9. dissolutionThe residue was dissolved in formic acid (5 mL)
10. stirringthe mixture was stirred at room temperature for 1 hour
11. concentrationThe reaction mixture was concentrated
12. extractionextracted with chloroform three times
13. washThe combined organic layers were washed with water
14. concentrationconcentrated under reduced pressure
15. dissolutionThe residue was dissolved in methanol (30 mL)
16. additionchloroform (15 mL), a 1N aqueous solution of sodium hydroxide was added under ice-
17. temperaturecooling
18. stirringand the mixture was stirred at the same temperature for 10 minutes
19. extractionthe mixture was extracted with chloroform three times
20. washThe combined organic layers were washed with water and saturated brine
21. dry with materialdried over magnesium sulfate
22. filtrationfiltered
23. concentrationconcentrated under reduced pressure
24. customThe residue was recrystallized from ethanol-diisopropyl ether

ORD record

ord-e14a0121fc6b4558a68428f8fe9aa731

Source dataset

uspto-grants-2006_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07008940B1