反应详情

To a solution of 650 mg (4.23 mmol) of the above-obtained 5-formylimidazo[5,1-b]thiazole in 10 ml of methanol were added 30 ml of methyl orthoformate and 486 mg of p-toluenesulfonic acid monohydride. The mixture was refluxed for 4 hours, and then cooled to room temperature. To this was added 2 ml of a 28% sodium methoxide/methanol solution, and the mixture was stirred for 10 minutes. The reaction solution was concentrated under reduced pressure. The residue was dissolved in methylene chloride, and the solution was successively washed with water and a saturated saline solution. The organic layer was dried over anhydrous magnesium sulfate, concentrated under reduced pressure, and purified by flash column chromatography using silica gel, eluting with a 1:9 mixture of hexane and ethyl acetate to give 694 mg (yield 83%).of the title compound as an red-brown oil.

1. temperatureThe mixture was refluxed for 4 hours
2. concentrationThe reaction solution was concentrated under reduced pressure
3. dissolutionThe residue was dissolved in methylene chloride
4. washthe solution was successively washed with water
5. dry with materialThe organic layer was dried over anhydrous magnesium sulfate
6. concentrationconcentrated under reduced pressure
7. custompurified by flash column chromatography
8. washeluting with a 1:9 mixture of hexane and ethyl acetate
9. customto give 694 mg (yield 83%)