Tetrahydrofuran → 3-Amino-1-cyclopropyl-6,7-difluoro-1H-quinazoline-2,4-dione

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Reaction Conditions

Reaction Steps

To a solution of a 1-cyclopropyl-6,7-difluoro-1H-quinazoline-2,4-dione (Example 23) in 1:1 dry tetrahydrofuran or dioxane and dry N,N-dimethylformamide is added portionwise sodium hydride (1.1 eq., 60% mineral oil dispersion) at room temperature. After stirring at 50° C. for 20 to 30 minutes, the resulting solution is cooled to room temperature and 2,4-dinitrophenylhydroxylamine (4 eq.) is added. The mixture is heated at 60° C. to 80° C. for 30 minutes, cooled, and the dioxane removed reduced pressure. The residue is poured into ice water and extracted with ethyl acetate. The organic layers are combined, washed with brine, dried with Na2SO4, and concentrated in vacuo. The residue is purified by flash column chromatography (ethyl acetate/hexanes) to afford a 3-amino-1-cyclopropyl-6,7-difluoro-1H-quinazoline-2,4-dione.

Provenance & Evidence