反应详情

300 mg (1.07 mmol) of 3,3-difluoro-3,4-dihydro-2H-thieno[3,4-b][1,4]-dioxepine-6,8-dicarboxylic acid was heated at 175° C. with 77 mg of copper chromite in 3.0 mL of quinoline for 1.5 hours. After cooling and mixing with 35 mL of tert-butyl methyl ether, the resulting mixture was washed three times with 2N hydrochloric acid, then three times with deionized water, dried with anhydrous magnesium sulphate and finally evaporated to dryness yielding 138 mg of raw product. The raw product was purified by column chromatography using Kieselgel 60 and cyclohexane as eluant. 82 mg of 3,3-difluoro-3,4-dihydro-2H-thieno[3,4-b][1,4]-dioxepine (M3) was obtained corresponding to a yield of 40% with a melting point of 66–67° C., as characterized by:

1. temperatureAfter cooling
2. washthe resulting mixture was washed three times with 2N hydrochloric acid
3. dry with materialthree times with deionized water, dried with anhydrous magnesium sulphate
4. customfinally evaporated to dryness
5. customyielding 138 mg of raw product
6. customThe raw product was purified by column chromatography