Reaktion #2186682

Reaktionsgleichung

Bromine

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

→

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

Lösungsmittel

AcOH

AcOH

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigeto give a brown precipitate
2. 2
   Sonstigethe resulting reaction mixture
3. 3
   workup.ADDITIONwas added until the liquid phase
4. 4
   SonstigeThe precipitate was removed by filtration
5. 5
   Sonstigerecrystallized from EtOH

Vorschrift

Bromine (10.8 mL, 210 mmol) in AcOH (50 mL) was added carefully to a solution of 2-(1H-pyrazol-1-yl)pyridine (11 g, 70 mmol) in AcOH (100 mL) to give a brown precipitate. After stirring at ambient temperature for 3 h, the resulting reaction mixture was poured into ice and saturated aqueous Na2SO2O5 was added until the liquid phase became clear. The precipitate was removed by filtration and recrystallized from EtOH:H2O to give 2-(4-bromo-1H-pyrazol-1-yl)pyridine as beige crystals. 1H NMR (CD3Cl, 300 MHz) δ 8.61 (1H, s), 8.42 (1H, br. s), 7.94-7.96 (1H, m), 7.84 (1H, ddd), 7.69 (1H, s), 7.21-7.28 (1H, m). MS (ESI) 225 (M+H)+

Quelle