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

4-(2,3-difluoro-phenyl)-1H-indole 6c (744 mg, 3.25 mmol) was dissolved in 12 ml of ethanol under stirring, and added successively with tert-butanol (21 ml), glacial acetic acid (6.4 ml) and pyridinium tribromide (3.12 g, 9.7 mmol) at room temperature. Upon completion of the addition, the reaction mixture was stirred for 3 hours, added with glacial acetic acid (16 ml) and zinc dust (1.1 g, 16.25 mmol), and stirred for another 1 hour. The reaction mixture was filtered and concentrated under reduced pressure. The residue was added with ethyl acetate (30 ml), washed successively with water (10 ml), saturated sodium bicarbonate solution (10 ml) and saturated brine (10 ml), dried over anhydrous sodium sulfate, filtered to remove the drying agent and concentrated under reduced pressure to obtain 4-(2,3-difluoro-phenyl)-1,3-dihydro-indol-2-one 6d (780 mg, yield 97%) as a white solid.

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

ORD record

ord-6b99baa547f94c3798ae719d931084f7

Source dataset

uspto-grants-2012_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08329682B2