Microwave-assisted synthesis of 1-aryl-1H-indazoles via one-pot two-step Cu-catalyzed intramolecular N-arylation of arylhydrazones
2005; Elsevier BV; Volume: 46; Issue: 44 Linguagem: Inglês
10.1016/j.tetlet.2005.08.143
ISSN1873-3581
AutoresPabba Chittari, Hongjun Wang, Susan R. Mulligan, Zhen‐Jia Chen, Todd M. Stark, Brian T. Gregg,
Tópico(s)Chemical Synthesis and Analysis
ResumoA highly efficient one-pot two-step microwave procedure was developed for the synthesis of 1-aryl-1H-indazoles. Microwave heating of 2-halobenzaldehydes or 2-haloacetophenones with phenylhydrazines at 160 °C for 10 min quantitatively yielded the arylhydrazones, which were further cyclized to give 1-aryl-1H-indazoles via CuI/diamine-catalyzed N-arylation under microwave heating (160 °C, 10 min). Good to excellent yields were observed for 2-iodo, 2-bromo, and 2-chloro benzaldehydes or acetophenones.
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