Synthesis of Pyridazinones through the Copper(I)‐Catalyzed Multicomponent Reaction of Aldehydes,Hydrazines, and Alkynylesters |
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| Authors: | Anderson C Mantovani Tales A C Goulart Prof Dr Davi F Back Prof Dr Gilson Zeni |
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| Institution: | 1. Departamento de Química Organica Laboratório de Síntese, Reatividade, Avalia??o Farmacológica e Toxicológica de Organocalcogênios, Universidade Federal de Santa Maria, Santa Maria, Rio Grande do Sul, 97105‐900 (Brazil);2. Departamento de Química Inorganica Laboratório de Materiais Inorganicos, Universidade Federal de Santa Maria, Santa Maria, Rio Grande do Sul, 97105‐900 (Brazil) |
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| Abstract: | The copper‐catalyzed multicomponent cyclization reaction, which combined aldehydes, hydrazines, and alkynylesters, was applied in the synthesis of pyridazinones. The reaction was regioselective and gave only six‐membered pyridazinones in the complete absence of five‐membered pyrazoles or a regioisomeric mixture. During this investigation, the use of 2‐halobenzaldehyde as the starting material, under identical reaction conditions, gave 6‐(2‐ethoxyphenyl)pyridazinones after sequential Michael addition/1,2‐addition/Ullmann cross‐coupling reactions. |
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| Keywords: | copper cyclization heterocycles homogeneous catalysis multicomponent reactions |
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