Pyrido annelation reaction by a tandem aza Wittig/electrocyclic ring-closure strategy: Preparation of pyrazolo[4,3-c]- and pyrazolo[3,4-c]pyridine derivatives.
作者:Pedro Molina、Enrique Aller、Angeles Lorenzo
DOI:10.1016/s0040-4020(01)82325-5
日期:1991.8
Wittig-type reaction of iminophosphorane 3, prepared from 5-formyl-1-phenylpyrazole by sequential treatment with ethyl azidoacetate and triphenylphosphine, with isocyanates, ketenes, aldehydes and carbon disulfide leads to the functionalized pyrazolo[4,3-c]pyridines 5,7,9 and 11 respectively. Iminophosphorane 15, prepared from 4-formyl-1-phenylpyrazole, under goes pyrido annelation by reaction with ketenes
膦亚胺的氮杂维蒂希型反应3,通过与叠氮基乙酸乙酯和三苯基膦,用异氰酸酯,烯酮,醛和二硫化碳通向官能吡唑并[4,3-C]吡啶序贯治疗由5-甲酰基-1-苯基吡唑制备5,7,9和11。膦亚胺15,由4-甲酰基-1-苯基吡唑制备下推移吡啶并成环通过与烯酮反应,得到同分异构的吡唑并[3,4-C]吡啶22在适度的产率。