反应详情

A stirred solution of 14.9 grams (0.042 mole) of 1-methyl-5-difluoromethoxy-4-chloro-3-(2-fluoro-4-chloro-5-nitrophenyl)pyrazole and 20 mL of water in 200 mL of acetic acid was warmed to 50° C., and 10.0 grams (0.179 mole) of iron powder was added portionwise. Upon completion of addition the reaction mixture was allowed to cool to ambient temperature. The reaction mixture was then poured into about 400 mL of a mixture of 1:1 ethyl acetate and water. The mixture was filtered through diatomaceous earth, and the organic layer in the filtrate was separated. The aqueous layer was washed with about 200 mL of ethyl acetate, and the wash was combined with the organic layer separated from the filtrate above. The combination was dried with magnesium sulfate and filtered. The filtrate was concentrated under reduced pressure to a residue. The residue was subjected to column chromatography on silica gel, using 5% methanol in methylene chloride as the eluant. The product-containing fractions were combined and concentrated under reduced pressure, yielding 12.2 grams of 1-methyl-5-difluoromethoxy-4-chloro-3-(2-fluoro-4-chloro-5-aminophenyl)pyrazole. The NMR spectrum was consistent with the proposed structure.

1. additionUpon completion of addition the reaction mixture
2. filtrationThe mixture was filtered through diatomaceous earth
3. customthe organic layer in the filtrate was separated
4. washThe aqueous layer was washed with about 200 mL of ethyl acetate
5. customseparated from the filtrate above
6. dry with materialThe combination was dried with magnesium sulfate
7. filtrationfiltered
8. concentrationThe filtrate was concentrated under reduced pressure to a residue
9. concentrationconcentrated under reduced pressure