反应详情

2-Aminoethylbenzimidazole dihydrochloride (Bull. Soc. Chem. Fr. 1991, 128, 255-259; 2.34 g, 10 mmol), phthalic anhydride (1.63 g. 11 mmol) and triethylamine (2.79 ml, 20 mmol) in chloroform (25 ml) were heated at reflux overnight , and the mixture was then cooled to room temperature, diluted with ethyl acetate and filtered off. The filtrate was washed with saturated sodium carbonate solution, buffer (pH=7) and saturated sodium chloride solution and dried over sodium sulphate. Chromatography (dichloromethane:methanol 10:1, Rf=0.4) gave 2.08 g of 2-(2-phthalimidylethyl)benzimidazole (71.4% of theory) as a colourless foam. MS (DCl, NH3)=292 (M+H+). 1H-NMR (DMSO-d6): 3.15 (2H, t); 4.0 (2H, t); 7.05-71 (2H, m); 7.4-7.5 (2H, m); 7.8-7.9 (4H, m); 12.4 (1H, br s).

1. temperatureat reflux overnight
2. filtrationfiltered off
3. washThe filtrate was washed with saturated sodium carbonate solution, buffer (pH=7) and saturated sodium chloride solution
4. dry with materialdried over sodium sulphate