Sodium Hydroxide → 5-chloro-2-(m-trifluoromethylphenyl)-4H-3,1-benzoxazin-4-one

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Reaction Steps

48 g of 3-trifluoromethylbenzoyl fluoride and 20 g of 50% strength aqueous sodium hydroxide solution are added simultaneously via 2 feed apparatuses in the course of 25 minutes at from 25° to 36° C. to a stirred mixture of 42.9 g of 6-chloroanthranilic acid and 0.45 g of triethylbenzylammonium chloride and 700 g of toluene. Stirring is continued for 90 minutes at 27° C., after which the water is separated off at from 87° to 104° C. After the addition of 32.7 g of thionyl chloride in the course of 15 minutes at 70° C., stirring is continued for 90 minutes at 82° C. The mixture is extracted once with water and once with 0.4 N sodium hydroxide solution, and is evaporated down to give 75 g (92%) of 5-chloro-2-(m-trifluoromethylphenyl)-4H-3,1-benzoxazin-4-one of melting point 116°-120° C.

Provenance & Evidence