Reactions of 1-aryl- and 2,3-diaryl- 5-diazo-6,6-dimethyl-4-oxo-4,5,6,7-tetra- hydroindazoles with N-ethyl- and N-phenyl-substituted maleimides

Abstract

Keywords: 1,3-and 2,3-substituted 5-diazo-6, 6-dimethyl-4-oxo-4,5,6,7-tetrahydroindazoles, N-ethyland N-phenylmaleimides, [3+2] cycloaddition reactions.In the last decade new methods of synthesis of indazoles have been designed, and include hydrogenated indazoles [1][2][3][4][5][6][7][8]. This is the result of the varied biological action of a large number of synthesized indazole derivatives. Among them have been discovered agonists and antagonists of estrogen receptors [9, 10], dopamine D-3 [11,12], corticotropin [13], and adenosine [14]; derivatives have been found with antitumor [15], antiinflammatory [16], and antimicrobial [17] action; inhibitors of HIV proteases [18] and membrane-active substances [19] have been discovered. Indazole derivatives have also been used as ligands [20].Previously, based on 4,5-dioxo-, 4-chloro-5-formyl-, and 5-diazo-4-oxo derivatives of 4,5,6,7-tetrahydroindazoles obtained by us, we synthesized a series of derivatives of them annelated with heterocycles [21][22][23][24].The interaction of 1-aryl-and 2,3-diaryl-5-diazo-4-oxo-4,5,6,7-tetrahydroindazoles of types 1 and 2 with maleic anhydride and acetylenedicarboxylic acid ester has been carried out. This led to the formation of the corresponding 3-spiropyrazoline and pyrazole derivatives of 4,5,6,7-tetrahydroindazole [25].