Ethyl 5-bromo-4-fluoro-2-nitrobenzeneacetate → 5‐bromo‐6‐fluoro‐2,3‐dihydro‐1H‐indol‐2‐one

Temperature

60 °C

To a 250 mL round bottom flask was added ethyl 2-(5-bromo-4-fluoro-2-nitrophenyl)acetate (5.2 g, 17 mmol), iron (4.7 g, 85 mmol) and 50 mL of AcOH. The reaction mixture was heated at 60° C. for 1 hour. The reaction mixture was then concentrated, dissolved in 100 mL of EtOAc, filtered, and washed with 50 mL of a saturated NaHCO3 solution. The organic layer was concentrated and purified with silica gel column chromatography, eluting with 40% EtOAc/hexane to give 5-bromo-6-fluoroindolin-2-one (3.4 g, 87% yield) as a white solid. MS m/z: 230 (M+1). 1H NMR (400 MHz, CD3OD) δ ppm 3.49-3.54 (m, 2H), 6.77 (d, J=8.80 Hz, 1H), 7.45 (d, J=6.65 Hz, 1H).

1. concentrationThe reaction mixture was then concentrated
2. dissolutiondissolved in 100 mL of EtOAc
3. filtrationfiltered
4. washwashed with 50 mL of a saturated NaHCO3 solution
5. concentrationThe organic layer was concentrated
6. custompurified with silica gel column chromatography
7. washeluting with 40% EtOAc/hexane

ORD record

ord-dbe64238e2444133a144f12e03ce0362

Source dataset

uspto-grants-2011_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08084479B2