A Microwave-Assisted Synthesis of Julolidine-9-carboxamide Derivatives and Their Conversion to Chalcogenoxanthones via Directed Metalation

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• 作者：Jason J. Holt ; Brandon D. Calitree ; Josiah Vincek ; Michael K. Gannon ; II ; Michael R. Detty
• 刊名：Journal of Organic Chemistry
• 出版年：2007
• 出版时间：March 30, 2007
• 年：2007
• 卷：72
• 期：7
• 页码：2690 - 2693
• 全文大小：75K
• 年卷期：v.72,no.7(March 30, 2007)
• ISSN：1520-6904

文摘

9-Formyljulolidine was oxidized via a microwave-assistedWillgerodt-Kindler reaction to the N-piperidine or N-morpholine julolidine-9-thioamide. 9-Formyl-1,1,7,7-tetramethyljulolidine gave the corresponding N-piperidine tetramethyljulolidine-9-thioamide. The thioamides were convertedto the corresponding carboxamides with trifluoroaceticanhydride. The amide group directed ortho-metalation in thejulolidine system, but not in the tetramethyljulolidine system.The resulting anion was captured by dichalcogenide electrophiles. The resulting products were converted to chalcogenoxanthones with phosphorus oxychloride and triethylamine (POCl₃/Et₃N).