反应详情

To a solution of N-(2,4-dimethoxybenzyl)-1,3,4-thiadiazol-2-amine (WO 2010/079443; 5.00 g, 19.9 mmol) in THF (60 mL), lithium bis(trimethylsilyl)amide (1.0 M solution in THF; 24.0 mL, 24.0 mmol) was added at −78° C. The reaction solution was stirred at room temperature for 10 minutes, and a solution of 5-chloro-2,4-difluorobenzenesulfonyl chloride (5.41 g, 21.9 mmol) in THF (15 mL) was then added thereto at −78° C. The reaction solution was stirred at room temperature for 2 hours, and water (100 mL) was then added to the reaction solution, followed by extraction with ethyl acetate (100 mL). The thus obtained organic layer was washed with saturated saline (100 mL) and dried over anhydrous sodium sulfate. After vacuum concentration, the residue was purified with silica gel chromatography (hexane/ethyl acetate=9:1) to yield the title compound (5.31 g, 58%) as a colorless solid.

1. customat −78° C
2. stirringThe reaction solution was stirred at room temperature for 2 hours
3. extractionfollowed by extraction with ethyl acetate (100 mL)
4. washThe thus obtained organic layer was washed with saturated saline (100 mL)
5. dry with materialdried over anhydrous sodium sulfate
6. concentrationAfter vacuum concentration
7. customthe residue was purified with silica gel chromatography (hexane/ethyl acetate=9:1)