Indole derivatives CXV. Synthesis and some transformations of 5-(3-indolyl)isoxazole-3-carboxylic acid

5-(3-Indolyl)isoxazole-3-carboxylic acid and its amide and hydrazide were obtained from ethyl 5-(3-indolyl)isoxazole-3-carboxylate. When 5-(3-indolyl)isoxazole-3-carboxylate is heated, it undergoes decarboxylation with isomerization to 3-(-cyanoacetyl)indole; when it is heated in alcohol with hydrazine and phenylhydrazine in the presence of copper, it undergoes isomerization to 5-(3-indolyl)pyrazole-3-carboxylic and 1-phenyl-5-(3-indolyl)-pyrazole-3-carboxylic acids. 5-(3-Indolyl)pyrazole-3-carboxylic acid hydrazide is formed when a solution of ethyl 5-(3-indolyl)isoxazole-3-carboxylate is refluxed with hydrazine in 96% alcohol.See 1] for communication CXIV.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 936–938, July, 1978.