Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5215423 | Tetrahedron | 2015 | 15 Pages |
1,5-Disubstituted-4-oxo-4,5-dihydro-1H-pyrazolo[4,3-c]pyridine-7-carboxamides functionalized at positions 1, 5, and 7 were prepared in six straightforward steps from cheap, commercially available dialkyl acetone-1,3-dicarboxylate. Due to the instability of methyl 1-benzyl-substituted pyrazolo[4,3-c]pyridine-7-carboxylates under basic hydrolytic conditions (LiOH/H2O), a detour via the corresponding benzyl esters was introduced to deliver the final 1-benzyl-substituted-bicyclic carboxamides in seven steps. The designed synthetic route is suitable for the construction of a larger library of compounds. All the key compounds have been characterized by NMR spectroscopic techniques and X-ray analysis.
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