反应详情

To a suspension of sodium hydride, 60% dispersion in mineral oil solution (1.6 g, 40 mmol) in tetrahydrofuran (50 ml) is added a solution of (2-bromothiazol-5-yl)methanol (6.75 g, 35 mmol) in tetrahydrofuran (50 ml) at 0° C. A solution of 5-chloro-2,2,6,6-tetramethylcyclohex-4-ene-1,3-dione (7.0 g, 35 mmol) in tetrahydrofuran (50 ml) is then added and the reaction mixture is heated to reflux for 18 hours. The reaction mixture is poured into water, acidified to pH4 with dilute aqueous hydrochloric acid and extracted with ethyl acetate (4×50 ml). The combined organic layers are dried over anhydrous magnesium sulfate, filtered and the filtrate is evaporated to a brown oil. The crude product is purified by flash chromatography on silica gel to give 5-(2-bromothiazol-5-ylmethoxy)-2,2,6,6-tetramethylcyclohex-4-ene-1,3-dione (6.75 g).

1. temperaturethe reaction mixture is heated
2. temperatureto reflux for 18 hours
3. extractionextracted with ethyl acetate (4×50 ml)
4. dry with materialThe combined organic layers are dried over anhydrous magnesium sulfate
5. filtrationfiltered
6. customthe filtrate is evaporated to a brown oil
7. customThe crude product is purified by flash chromatography on silica gel