Nitrobenzisoxazoles, Nitrobenzoxazoles, and Nitrobenzoxadiazoles

An attempt to substitute hydroxynitrocumarines by nitrocumarines failed the yield of the final products fell to 5-17% [425], 

In 1912, Borsche found out that the esters and amides of 6-nitro-l,2-benzisox-azole-3-carboxylic acid could be obtained in high yield in the reaction of isoamyl-nitrite with 2,4-dinitrophenylacetic acid derivatives in the presence of sodium methoxide [426], 

6-Nitro-l,2-benzisoxazolylketones can be obtained in an analogous manner [426], 5-Nitrosalicilic aldehyde in an acid medium reacts with HN3 to form a mixture of 

5- nitro-l,2-benzisoxazole and 5-nitrobenzoxazole [429] - the latter being formed from 5-nitrosalicylic acid nitryl, a product of 5-nitro-l,2-benzisoxazole hydrolysis. 

On heating with concentrated sulfuric acid 2,4-dinitrophenylacetone turns into 

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