A facile method for the synthesis of substituted pyrazolo[3,4-c]pyridines

Methods for a facile high-yielding synthesis of substituted pyrazolo[3,4-c]pyridines from 2-bromo-5-fluoropyridine are described, along with a brief mechanistic discussion for the key cyclization step. The methods utilize inexpensive commercially available starting materials and unlike previous methods, are more suitable for SAR work and scale-up.