反应详情

温度

-40 °C

7-Hydroxyiminomethylimidazo[5,1-b]thiazole (a low-polarity geometrical isomer) (831 mg) was dissolved in 25 ml of THF and 5 ml of hexamethylphosphoramide (HMPA). A 1.55 N n-butyllithium/n-hexane solution (7.67 ml) was dropwise added in an argon atmosphere at −70° C. to the solution. The mixture was stirred at the same temperature for 40 min. Tri-n-butylstannyl chloride (1.84 ml) was added thereto. The mixture was stirred for 1.5 hr while raising the temperature to −40° C. An ammonium chloride solution was a added to the reaction solution, followed by extraction with ethyl acetate. The organic layer was washed with brine, dried over anhydrous magnesium sulfate, and filtered. The solvent was removed by distillation under the reduced pressure. The residue was purified by column chromatography on silica gel (hexane:ethyl acetate=3:1 to 1:1) to give 680 mg of 7-hydroxyiminomethyl-2-(tri-n-butylstannyl)imidazo[5,1-b]thiazole (a geometrical isomer derived from a starting compound as a low-polarity oxime isomer).

1. stirringThe mixture was stirred for 1.5 hr
2. additiona added to the reaction solution
3. extractionfollowed by extraction with ethyl acetate
4. washThe organic layer was washed with brine
5. dry with materialdried over anhydrous magnesium sulfate
6. filtrationfiltered
7. customThe solvent was removed by distillation under the reduced pressure
8. customThe residue was purified by column chromatography on silica gel (hexane:ethyl acetate=3:1 to 1:1)