Phosphorus oxychloride → 2-Chloro-4,4'-bipyridine

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

The suspension of 4,4′-bipyridine-1-oxide (8.50 g, 49.36 mmol) in phosphorus oxychloride (80 mL) was heated to 110° C. overnight. The mixture was concentrated and the residue was treated with saturated aqueous NaHCO3 solution (150 mL) slowly and then Na2CO3 solution (2M) until it was basic. The alkaline solution was extracted with chloroform (4×300 mL). The combined organic layer was dried, treated with activated carbon and filtered through celite. The filtrate was concentrated and the resulting solid was purified by flash column chromatography (4% MeOH in CH2Cl2) to give 2-Chloro-4,4′-bipyridine (3-2) as a off-yellow solid. 1H NMR (CDCl3) δ 8.77 (dd, 2H, J=4.5, 1.6), 8.53 (d, 1H, J=5.1), 7.58 (s, 1H), 7.52 (dd, 2H, J=4.7, 1.7), 7.46 (dd, 1H, J=5.2, 1.5).

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