Synthesis of 3,5-difunctionalized 1-methyl-1H-pyrazolo[3,4-b]pyridines involving palladium-mediated coupling reactions |
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Authors: | G Lavecchia |
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Institution: | Institut de Chimie Organique et Analytique, UMR CNRS 6005, Université d’Orléans, BP 6759, 45067 Orleans Cedex 2, France |
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Abstract: | Indirect iodination of 2-chloro-nicotinonitrile gave 2-chloro-5-iodonicotinonitrile, which was cyclized with methylhydrazine to lead to 3-amino-5-iodopyrazolo3,4-b]pyridine. Position 3 was then protected by pivaloyl group and the resulting 5-iodo-3-pivaloylaminopyrazolo3,4-b]pyridine was engaged in palladium-promoted coupling reactions with various reagents to give 3-pivaloylamino-5-substituted compounds. Deprotection and iododediazoniation followed by cross-coupling reactions in position 3 afforded novel unsymmetrical 3,5-disubstituted pyrazolo3,4-b]pyridine species. |
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Keywords: | Pyrazolo[3 4-b]pyridines |
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