A Short Route to Heteroarylcarbazoles: Synthesis of New Pyrazolylcarbazoles and Carbazolylquinolines
作者:Paramasivan T. Perumal、Rajagopal Nagarajan
DOI:10.1055/s-2004-822353
日期:——
A short synthesis of pyrazolylcarbazoles from 9-alkylcarbazoles in three steps is reported. The acetylcarbazoles prepared by the acetylation of carbazoles with acetic anhydride catalyzed by BiCl3 were converted into chloroaldehydes with Vilsmeier reagent. Condensation of chloroaldehydes with hydrazine followed by cyclization yield the pyrazolylcarbazoles. Carbazolyl chalcones were prepared by the condensation of carbazole-3-aldehyde with o-aminoacetophenone and cyclized to carbazolylquinolone using several catalysts. Cyclization of carbazolyl chalcones with the Vilsmeier reagent yields a mixture of carbazolylquinoline carbaldehydes.
报道了由 9-烷基咔唑分三步短合成吡唑基咔唑的方法。 BiCl3催化咔唑与乙酐乙酰化制备乙酰咔唑,用Vilsmeier试剂将其转化为氯醛。氯醛与肼缩合,然后环化产生吡唑基咔唑。咔唑基查耳酮是通过咔唑-3-醛与邻氨基苯乙酮缩合制备的,并使用多种催化剂环化为咔唑基喹诺酮。用 Vilsmeier 试剂环化咔唑基查耳酮,产生咔唑基喹啉甲醛的混合物。