Tetrahydrofuran → 3-bromo-N-[4,6-dibromo-2-(N,N'-dimethylhydrazinocarbonyl)phenyl]-1-(3-chloro-2-pyridinyl)-1H-pyrazole-5-carboxamide

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Reaction Steps

To a mixture of 0.42 g of N,N′-dimethylhydrazine dihydrochloride, five drops of water, 0.87 g of potassium carbonate and 10 ml of tetrahydrofuran was added 0.60 g of 2-[3-bromo-1-(3-chloro-2-pyridinyl)-1H-pyrazol-5-yl]-6,8-dibromo-4H-3,1-benzoxazine-4-one. The resulting mixture was stirred at room temperature for 19 hours. Water was poured into the reaction mixture, and the mixture was extracted with ethyl acetate. The organic layer was washed successively with water and an aqueous saturated sodium chloride solution, dried over anhydrous magnesium sulfate, and concentrated under reduced pressure. The resulting residue was subjected to silica gel chromatography to obtain 0.51 g of 3-bromo-N-[4,6-dibromo-2-(N,N′-dimethylhydrazinocarbonyl)phenyl]-1-(3-chloro-2-pyridinyl)-1H-pyrazole-5-carboxamide of the formula:

Provenance & Evidence