Water → 3-(7-fluoro-3-oxo-2H-1,4-benzoxazin-6-yl)-1-methyl-6-trifluoromethyl-2-oxo-1,2-dihydropyrazine

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Reaction Conditions

Reaction Steps

Then, 2.8 g of iron powder was added to a mixture of 5 ml of acetic acid and 50 ml of water, and the mixture was heated to 50° C. To this was slowly added dropwise a solution of 2.8 g of 3-[4-(butoxycarbonylmethoxy)-2-fluoro-5-nitrophenyl]-1-methyl-6-trifluoromethyl-2-oxo-1,2-dihydropyrazine (the present compound obtained in step (3) above) in 25 ml of ethyl acetate and 25 ml of acetic acid. The mixture was stirred at an internal temperature of 60° to 70° C. for 1 hour. After completion of the reaction, the reaction mixture was poured into ice water, followed by extraction with ethyl acetate. The organic layer was washed with saturated sodium hydrogencarbonate solution, water, and saturated sodium chloride solution, dried with anhydrous magnesium sulfate, and concentrated, which afforded 1.22 g of 3-(7-fluoro-3-oxo-2H-1,4-benzoxazin-6-yl)-1-methyl-6-trifluoromethyl-2-oxo-1,2-dihydropyrazine (present compound 2-49; m.p., 182.5° C.).

Provenance & Evidence