反应详情

A solution of sodium nitrite (1.18 g, 0.0171 mol) in water (10 mL) was added dropwise to a mixture of (2-amino-thiazol-4-yl)acetic acid ethyl ester (2.60 g, 0.0140 mol), copper sulfate (6.84 g, 0.0429 mol), sodium bromide (5.89 g, 0.0573 mol) and 9 M hydrochloric acid aqueous solution (30 mL) at 0° C. over 10 minutes. After stirring at the same temperature for 20 minutes, the reaction solution was returned to room temperature over one hour and further stirred at room temperature for two hours. The reaction solution was diluted with water, filtered through celite and extracted with ethyl acetate. The organic layer was washed with brine, dried over anhydrous magnesium sulfate and concentrated under reduced pressure. The resulting residue was subjected to silica gel chromatography (n-hexane/ethyl acetate=1/0 to 9/1) to give the title compound (209.3 mg, 6%).

1. waitthe reaction solution was returned to room temperature over one hour
2. stirringfurther stirred at room temperature for two hours
3. filtrationfiltered through celite
4. extractionextracted with ethyl acetate
5. washThe organic layer was washed with brine
6. dry with materialdried over anhydrous magnesium sulfate
7. concentrationconcentrated under reduced pressure