Transformations of 4-Hydroxy-5,6,7,8-tetrafluorocoumarin Derivatives with Monoamines

Abstract

The 4-hydroxy-5,6,7,8-tetrafluorocoumarin reacts with the monoamines to form salts under the mild conditions or the 4-alkyl(aryl)aminocoumarins on refluxing in o-xylene. The 3-acetyl-4-hydroxy-5,6,7,8-tetrafluorocoumarin reacts with the strong basic amines in the polar solvents to give salts that can be transformed into the 3-alkylaminoethylidene-5,6,7,8-tetrafluorobenzopyran-2,4-diones. The latter can be obtained by reaction of the 3-acetylcoumarin with different amines. The reactions of the 3-acetylcoumarin with the strong basic amines in dimethyl sulfoxide lead to the 7-alkylamino-3-alkylaminoethylidene-5,6,8-triflurobenzopyrandiones. The 3-acetimidoyl-4-hydroxy-5,6,7,8-tetrafluoro-coumarin affords the 3-alkylaminoethylidenebenzopyrandiones with the monoamines, but in dimethyl sulfoxide the 7-substituted 3-acetimidoyl-5,6,8-trifluorobenzopyrandiones or the 7-alkylamino-3-alkylaminoethylidene-5,6,8-triflurobenzopyrandiones can be obtained.