反应详情

A stirred solution of 0.48 gram (0.0012 mole) of 1-(2,3,5,6-tetrafluoro-4-trifluoromethylphenyl)-5-hydroxymethylcarbonylamino-4-nitropyrazole and 0.27 gram (0.0027 mole) of triethylamine in 28.5 mL of methylene chloride was cooled in an ice-water bath. Methylaminosulfonyl chloride (0.55 gram, 0.0043 mole) was added dropwise, and the mixture was allowed to warm to room temperature and stir for four hours. The reaction mixture was filtered to remove a salt that had formed. The filtrate was extracted in succession with water, dilute hydrochloric acid, a saturated, aqueous sodium bicarbonate solution, and water. The organic phase was dried over anhydrous magnesium sulfate and filtered. The filtrate was evaporated under reduced pressure, leaving a brown oil. This oil was purified by column chromatography on silica gel, which was eluted with ethyl acetate: n-heptane (1:1) to yield an oil. This oil crystallized in methylene chloride and n-heptane to yield 0.07 gram of 1-(2,3,5,6-tetrafluoro-4-trifluoro methylphenyl)-5-methylaminosulfonyloxymethylcarbonylamino-4-nitropyrazole as an ivory-colored solid (Compound 21 of Table 1). The nmr spectrum was consistent with the proposed structure.

1. filtrationThe reaction mixture was filtered
2. customto remove a salt that
3. customhad formed
4. extractionThe filtrate was extracted in succession with water, dilute hydrochloric acid
5. dry with materialThe organic phase was dried over anhydrous magnesium sulfate
6. filtrationfiltered
7. customThe filtrate was evaporated under reduced pressure
8. customleaving a brown oil
9. customThis oil was purified by column chromatography on silica gel, which
10. washwas eluted with ethyl acetate: n-heptane (1:1)
11. customto yield an oil
12. customThis oil crystallized in methylene chloride