Acetic Acid → 4-(2,3-Difluoro-phenyl)-1,3-dihydro-indol-2-one

4-(2,3-Difluoro-phenyl)-1H-indole 3c (744 mg, 3.25 mmol) was dissolved in 12 mL of ethanol under stirring at room temperature, and 21 mL of tert-butanol, 6.4 mL of glacial acetic acid and pyridinium tribromide (3.12 g, 9.7 mmol) were then added successively to the solution. Upon completion of the addition, the reaction mixture was stirred for 3 hours, and 16 mL of glacial acetic acid and zinc dust (1.1 g, 16.25 mmol) were then added to the mixture. The reaction mixture was stirred for another 1 hour, filtered to remove the residue and concentrated under reduced pressure. The residue was added with 30 mL of ethyl acetate, washed successively with 10 mL of water, 10 mL of saturated sodium bicarbonate solution and 10 mL of saturated brine, dried over anhydrous sodium sulfate and filtered to remove the drying agent. The filtrate was concentrated under reduced pressure to give the title compound 4-(2,3-difluoro-phenyl)-1,3-dihydro-indol-2-one 3d (780 mg, yield 97%) as a white solid.

1. additionUpon completion of the addition
2. stirringthe reaction mixture was stirred for 3 hours
3. stirringThe reaction mixture was stirred for another 1 hour
4. filtrationfiltered
5. customto remove the residue
6. concentrationconcentrated under reduced pressure
7. additionThe residue was added with 30 mL of ethyl acetate
8. washwashed successively with 10 mL of water, 10 mL of saturated sodium bicarbonate solution and 10 mL of saturated brine
9. dry with materialdried over anhydrous sodium sulfate
10. filtrationfiltered
11. customto remove the drying agent
12. concentrationThe filtrate was concentrated under reduced pressure

ORD record

ord-065d59e9aa7c4dcaba883f94e1afedb9

Source dataset

uspto-grants-2012_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08299069B2