反应详情

To a stirred solution of 5-azabenzimidazole (0.300 g, 2.51 mmol) in anhydrous DMF (5 mL) was added N,N-diisopropylethylamine (0.66 mL, 3.80 mmol) followed by 2-(trimethylsilyl)ethoxymethyl chloride (0.54 mL, 3.02 mmol). The resultant solution was heated to 80° C. for 2 h then cooled to room temperature. The reaction mixture was poured into brine (20 mL) and diluted with ethyl acetate (30 mL). The phases were separated and the aqueous phase was extracted with ethyl acetate (3×15 mL). The combined organic extracts were washed with brine (3×5 mL), dried (MgSO4), and concentrated under reduced pressure. Purification of the crude brown oil through a plug of silica gel (CH2Cl2/MeOH, 9:1) provided the 1-(2-trimethylsilylethoxymethyl)-5-aza-benzimidazole (0.586 g, 93%) as an orange oil. General Procedure: Formylation of benzimidazoles

1. customThe phases were separated
2. extractionthe aqueous phase was extracted with ethyl acetate (3×15 mL)
3. washThe combined organic extracts were washed with brine (3×5 mL)
4. dry with materialdried (MgSO4)
5. concentrationconcentrated under reduced pressure
6. customPurification of the crude brown oil through a plug of silica gel (CH2Cl2/MeOH, 9:1)