Reaktion #2186684

Reaktionsgleichung

2-(4-bromo-1H-pyrazol-1-yl)pyridine

3-chlorophenylboronic acid

potassium carbonate

→

2-[4(3-chlorophenyl)-1H-pyrazol-1-yl]pyridine

Lösungsmittel

ethyleneglycol dimethyl ether

H2O

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigewere degassed by argon bubbling for 15 min.
2. 2
   Sonstigedegasing
3. 3
   workup.ADDITIONwas added
4. 4
   Extraktionextracted with EtOAc (3×30 mL)
5. 5
   Waschenthe combined extracts washed with brine
6. 6
   TrocknenThe organic phase was dried over Na2SO4
7. 7
   Einengenconcentrated in vacuo
8. 8
   Sonstigethe crude residue was chromatographed on silica gel eluting with EtOAc:hexane (1:4)
9. 9
   Sonstigeto afford a white solid which
10. 10
    Sonstigewas recrystallized from EtOAc/Hexane

Vorschrift

A solution of 2-(4-bromo-1H-pyrazol-1-yl)pyridine (0.669 g, 3 mmol), 3-chlorophenylboronic acid (0.468 g, 3 mmol) and potassium carbonate (0.828 g, 6 mmol) in a mixture of ethyleneglycol dimethyl ether (20 mL) and H2O (4 mL) were degassed by argon bubbling for 15 min., then tetrakis(triphenylphosphine)palladium(0) (20 mg, 0.017 mmol) was added and degasing continued a further 15 min. The solution was stirred at 70° C. for 14 h, whereupon H2O (30 mL) was added, then extracted with EtOAc (3×30 mL) and the combined extracts washed with brine. The organic phase was dried over Na2SO4, concentrated in vacuo and the crude residue was chromatographed on silica gel eluting with EtOAc:hexane (1:4) to afford a white solid which was recrystallized from EtOAc/Hexane to give 2-[4(3-chlorophenyl)-1H-pyrazol-1-yl]pyridine. MP=110-111° C. 1H NMR (CD3Cl, 300 MHz) δ 8.83 (d, 1H), 8.42 (dd, 1H), 7.99 (s, 1H), 7.99 (d, 1H), 7.82 (ddd, 1H), 7.57 (t, 1H), 7.45 (dt, 1H), 7.32 (t, 1H), 7.25˜7.18 (m, 2H). MS (ESI) 255.9 (M++H).

Quelle