[OH:1][CH2:2][C:3]1[N:7]2[CH:8]=[CH:9][CH:10]=[CH:11][C:6]2=[N:5][C:4]=1[C:12]([O:14][CH2:15][CH3:16])=[O:13].C[N+]1([O-])CCOCC1>ClCCl.[Ru]([O-])(=O)(=O)=O.C([N+](CCC)(CCC)CCC)CC>[CH:2]([C:3]1[N:7]2[CH:8]=[CH:9][CH:10]=[CH:11][C:6]2=[N:5][C:4]=1[C:12]([O:14][CH2:15][CH3:16])=[O:13])=[O:1]A solution of 1.2 g (5.45 mmol) of ethyl 3-(hydroxymethyl)-imidazolo[1,2-a]pyridine-2-carboxylate in 50 mL dichloromethane is treated with 1.75 g (15.0 mmol) of N-methylmorpholine N-oxide, 2.5 g powdered 4A molecular sieves and 180 mg (0.5 mmol) tetrapropylammonium perruthenate. The mixture is stirred at room temperature for 2 hr and applied directly to a column of silica. The column is eluted with 10% methanol in dichloromethane to afford 1.09 g (92%) ethyl 3-formyl-imidazolo[1,2-a]pyridine-2-carboxylate.
Wird geladen…
