Reaktion #10795

Reaktionsgleichung

2-(2,4-dimethoxy-phenyl)-3H-imidazo[4,5-b]pyridine

1,1-dichlorodimethyl ether

→

5-(3H-imidazo[4,5-b]pyridin-2-yl)-2,4-dimethoxy-benzaldehyde

Ausbeute 64.4%

Lösungsmittel

CH2Cl2

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONwas added
2. 2
   workup.WAITroom temperature for overnight
3. 3
   Filtrationthe precipitate was filtered

Vorschrift

Ex-76B: To a suspension of 2-(2,4-dimethoxy-phenyl)-3H-imidazo[4,5-b]pyridine (0.44 g, 1.7 mmol) in 20 ml of CH2Cl2, 1,1-dichlorodimethyl ether (0.55 g, 4.8 mmol) was added. The mixture was cooled to 0° C. with a water-ice bath, and 7 ml (7 mmol) of TiCl4 (1.0 m in CH2Cl2) was added dropwise. The mixture was stirred at 0° C. for 2 hrs, then room temperature for overnight. The reaction mixture was poured into ice-water and the precipitate was filtered to give 0.31 g (63%) of 5-(3H-imidazo[4,5-b]pyridin-2-yl)-2,4-dimethoxy-benzaldehyde as a white solid. 1H-NMR (DMSO-d6) δ 10.22 (s, 1H), 8.67 (s, 1H), 8.56 (d, J=5 Hz, 1H), 8.44 (d, J=8 Hz, 1H), 7.57–7.61 (m, 1H), 6.97 (s, 1H), 4.19 (s, 3H), 4.06 (s, 3H). HMRS (EI) calc. for C15H13N3O3: 283.0957; found: 283.0952.

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