A general and efficient synthetic method for the synthesis of biologically important series of 3, 6-disubstituted-1H-pyrazolo [3, 4-b] pyridines was discovered. 2, 6-Difluoropyridine was deprotonated using 1.1 equiv of n-BuLi in THF at<− 60° C, followed by quenching with a variety of Weinreb amides to generate 2, 6-Difluoro-3-ketopyridines in high yields. A mild tandem reaction sequence of selective nucleophilic substitution of the 6-fluoride with a ...
