反应详情

To a mixture of the sodium salt of 5-methyl-4-(3-methylbutyl)-1,2,5-thiadiazolidin-3-one 1,1-dioxide (1 g; 4.13 mmol, prepared by treatment with sodium methoxide), pentafluoropyridine (0.54 ml, 4.97 mmol), and 0.91 g (4.13 mmol) of 15-Crown-5 suspended in 30 ml of acetonitrile was refluxed for 17 hours. The mixture was cooled, concentrated in vacuo, and the residue extracted with methylene chloride, and the organic layer was washed with water (3×) and brine. After drying over sodium sulfate, the organic layer was concentrated in vacuo and a crude product was purified by flash chromatography (10% ethyl acetate in hexane) to afford 0.62 g (41%) of 2-(2,3,5,6-tetrafluoro-4-pyridyl)-5-methyl-4-(3-methylbutyl)-1,2,5-thiadiazolidin-3-one 1,1-dioxide. (Formula I: R1 =(CH2)2 CH(CH3)2 ; R2 =H; R3 =CH3), as a solid, m.p. 80.5°-81.5° C.

1. temperaturewas refluxed for 17 hours
2. temperatureThe mixture was cooled
3. concentrationconcentrated in vacuo
4. extractionthe residue extracted with methylene chloride
5. washthe organic layer was washed with water (3×) and brine
6. dry with materialAfter drying over sodium sulfate
7. concentrationthe organic layer was concentrated in vacuo
8. customa crude product was purified by flash chromatography (10% ethyl acetate in hexane)