Reaktion #72333

Reaktionsgleichung

NBS

3-(2-(4-fluorophenyl)furo[2,3-b]pyridin-5-yl)benzoic acid

DMF

NBS

→

3-(3-bromo-2-(4-fluorophenyl)furo[2,3-b]pyridin-5-yl)benzoic acid

Ausbeute 53.0%

Lösungsmittel

THF

THF

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.DISSOLUTIONThe solids dissolved
2. 2
   Sonstigequenched with 10% Na2S2O3
3. 3
   SonstigeThe solvent was evaporated
4. 4
   workup.ADDITIONthe material was diluted with water
5. 5
   Filtrationfiltered
6. 6
   Sonstigedried
7. 7
   Sonstigeto afford
8. 8
   workup.ADDITIONa mixture of starting material and product
9. 9
   workup.WAITAfter 3 h
10. 10
    Sonstigethe reaction was quenched by the addition of 10% Na2S2O3
11. 11
    SonstigeThe volatiles were removed
12. 12
    Filtrationthe resulting off-white precipitate was collected by filtration
13. 13
    Waschenrinsed with water and Et2O
14. 14
    Sonstigeair-dried

Vorschrift

NBS (125 mg, 0.702 mmol) was added to a stirred suspension of 3-(2-(4-fluorophenyl)furo[2,3-b]pyridin-5-yl)benzoic acid (215 mg, 0.645 mmol) in THF (5 mL)/DMF (1 mL). The solids dissolved and the reaction was stirred at room temperature for 30 min, then quenched with 10% Na2S2O3, and acidified with 1N HCl. The solvent was evaporated and the material was diluted with water, filtered and dried to afford a mixture of starting material and product. The material was resubjected to the reaction conditions (80 mg of NBS in 3 mL THF/0.5 mL DMF). After 3 h, the reaction was quenched by the addition of 10% Na2S2O3, and the solution was acidified with 0.1N HCl. The volatiles were removed and the resulting off-white precipitate was collected by filtration, rinsed with water and Et2O, and air-dried to afford the expected product 3-(3-bromo-2-(4-fluorophenyl)furo[2,3-b]pyridin-5-yl)benzoic acid (140 mg, 53% yield) as an off-white powder consistent by LCMS and NMR. 1H NMR (400 MHz, DMSO-d6) δ ppm 8.73 (1H, d, J=2.26 Hz), 8.27-8.33 (2H, m), 8.19-8.26 (2H, m), 8.05-8.12 (1H, m), 8.03 (1H, d, J=7.78 Hz), 7.68 (1H, t, J=7.78 Hz), 7.45-7.55 (2H, m). LC-MS retention time: 1.20 min; m/z (MH+): 412, 414. LC data was recorded on a Shimadzu LC-10AS liquid chromatograph equipped with a Waters XBridge 5u C18 4.6×50 mm column using a SPD-10AV UV-Vis detector at a detector wave length of 220 nM. The elution conditions employed a flow rate of 5 ml/min, a gradient of 100% solvent A/0% solvent B to 0% solvent A/100% solvent B, a gradient time of 2 min, a hold time of 1 min, and an analysis time of 3 min where solvent A was 5% acetonitrile/95% H2O/10 mM ammonium acetate and solvent B was 5% H2O/95% acetonitrile/10 mM ammonium acetate. MS data was determined using a Micromass Platform for LC in electrospray mode.

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