反应详情

A solution of 2-bromoimidazo[5,1-b]thiazole-7-carboxylic acid (1.08 g, 4.37 mmol) in 1,2,4-trichlorobenzene (20 ml) was stirred at 220° C. for 4 hr. The reaction solution was allowed to cool to room temperature, was diluted with hexane, and was extracted with 4 M hydrochloric acid (8 ml×3). The aqueous layer was neutralized with a 10 M aqueous solution of sodium hydroxide and was extracted with ethyl acetate (10 ml×3). The organic layer was washed with saturated brine and was dried over anhydrous sodium sulfate. The solvent was removed by distillation under the reduced pressure, and the residue was purified by column chromatography on silica gel (hexane:ethyl acetate=1:1→1:2) to give 2-bromoimidazo[5,1-b]thiazole (744.8 mg, 84%) as a white solid.

1. extractionwas extracted with 4 M hydrochloric acid (8 ml×3)
2. extractionwas extracted with ethyl acetate (10 ml×3)
3. washThe organic layer was washed with saturated brine
4. dry with materialwas dried over anhydrous sodium sulfate
5. customThe solvent was removed by distillation under the reduced pressure
6. customthe residue was purified by column chromatography on silica gel (hexane:ethyl acetate=1:1→1:2)