Indazole 6-hydroxy-, diazo coupling

Indazole, 5,5-dimethyl-3-trifluoromethyl-4,5-dihydro-trichomonacidal activity, 5, 291 Indazole, 2-ethoxycarbonyl-reactions, 5, 269 Indazole, 3-fluoro-synthesis, S, 263 Indazole, 1-germyl-synthesis, 5, 236 Indazole, 1-glycosyl-synthesis, 5, 289 Indazole, 2-glycosyl-synthesis, 5, 289 Indazole, halo-reactions, S, 266 Indazole, 2-hydroxy-methylation, 5, 269 Indazole, 3-hydroxy-reactions, S, 264 Indazole, 6-hydroxy-diazo coupling, 5, 86 Indazole, hydroxyphenyl-synthesis, S, 288 Indazole, 3-iodo-synthesis, S, 241 Indazole, l-isopropyl-3-phenyl-reduction, 5, 243 Indazole, 3-mercapto-1 -substituted tautomerism, 5, 265 Indazole, methoxy-... 

Diazo coupling is expected to occur only with highly reactive systems, and experiment bears this out. Diazonium ions couple with the anions of A -unsubstituted imidazoles at the 2-position (e.g. 157 yields 158) and with indazoles (159) in the 3-position. In general, other azoles react only when they contain an amino, hydroxy, or potential hydroxy group, e.g. the 4-hydroxypyrazole (160), the triazolinone (161) and the thiazolidinedione (162) (all these reactions occur on the corresponding anions). 

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See also in sourсe #XX -- [ ]

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