Synthesis of 2,1-Benzisoxazoles by Nucleophilic Substitution of Hydrogen in Nitroarenes Activated by the Azole Ring

Abstract

Reaction of 1-nitro-4-(1,2,3-triazolyl/tetrazolyl)benzenes with arylacetonitriles in an alcoholic medium in the presence of excess alkali gives novel 2,1-benzisoxazoles. These findings indicate a high reactivity of nitroarenes activated by the azole ring due to their electron-deficient character. Moreover, it was found that annulation of the isoxazole ring occurred regioselectively in disubstituted nitroarenes. In the case of 1-(4-nitrophenyl)-1H-tetrazole, the tetrazole ring cleaved faster than the σ^H-adduct was formed.

Key words

1H-1,2,3-triazole - tetrazole - nucleophilic substitution - 2,1-benzisoxazole - annulation

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