Approach to the Library of Fused Pyridine-4-carboxylic Acids by Combes-Type Reaction of Acyl Pyruvates and Electron-Rich Amino Heterocycles
摘要:
A library of fused pyridine-4-carboxylic acids (including pyrazolo[3,4-b]pyridines, isoxazolo[5,4-b]pyridines, furo[2,3-b]pyridines, thieno[2,3-b]pyridines, and pyrido[2,3-d]pyrimidines) was generated by Combes-type reaction of acyl pyruvates and electron-rich amino heterocycles followed by hydrolysis of the ester. The library members were also demonstrated to undergo the standard combinatorial transformations including amide coupling and esterification, as well as less common heterocyclizations to 1,2,4-triazoles and 1,2,4-oxadiazoles.
Pyrazolopyridines I: Synthesis of Some Pyrazolo[3,4-b]pyridine-4-carboxylates
作者:Tahir Maqbool、Misbahul Ain Khan、Muhammad Naeem Khan、Mark C. Elliott、Munawar Ali Munawar、Muhammad Nasrullah、Abdul Waheed Bhatti、Areesha Nazeer、Whei-Oh Lin
DOI:10.14233/ajchem.2013.14573a
日期:——
A series of ethyl 3-methyl-1-phenyl-6-aryl-1H-pyrazolo[3,4-b]pyridine-4-carboxylates were prepared by the reaction of 5-amino-3-methyl-1-phenyl-1H-pyrazole with various aromatic aldehydes and ethyl pyruvate. The structure elucidation of the prepared compounds was carried out by spectroscopic techniques (mass, IR, H-1 and C-13 NMR).