[NH:1]1[CH:5]=[CH:4][N:3]=[C:2]1[CH:6]=[O:7].CCN(CC)CC.[S:15](Cl)([C:18]1[CH:24]=[CH:23][C:21]([CH3:22])=[CH:20][CH:19]=1)(=[O:17])=[O:16]>C(Cl)Cl>[C:21]1([CH3:22])[CH:23]=[CH:24][C:18]([S:15]([N:1]2[CH:5]=[CH:4][N:3]=[C:2]2[CH:6]=[O:7])(=[O:17])=[O:16])=[CH:19][CH:20]=1To a suspension of 2-imidazolecarboxaldehyde (1.01 g, 10.51 mmol) in CH2Cl2 (25 mL) was added Et3N (2.9 mL, 21.02 mmol) and tosyl chloride (3.01 g, 15.77 mmol) and the reaction mixture was heated to reflux overnight. Then the mixture was cooled and washed with saturated NH4Cl (4×30 mL). The organic layer was dried (MgSO4), filtered, and concentrated to afford a dark brown oil. Purification by flash column chromatography on silica gel using 2% MeOH/CH2Cl2 afforded 1-(toluene-4-sulfonyl)-1H-imidazole-2-carbaldehyde as a yellow oil (1.53 g, 58%). 1H NMR (CDCl3) δ 2.45 (s, 3H), 7.31 (s, 1H), 7.49 (d, 2H, J=6.0 Hz), 7.83 (s, 1H), 8.00 (d, 2H, J=7.5 hz), 9.78 (s, 1H).
Loading…
