Synthesis of 1H-pyrazolo[3,4-d]pyrimidines via solid-phase Aza-Wittig/electrocyclic ring closure reaction

An elegant solid-phase synthetic route of pyrazolo[3,4-d]pyrimidine derivatives via Aza-Wittig/electrocyclic ring closure reaction was developed and validated. By manipulating the R group from the primary amine building block, one can easily prepare the library of pyrazolo[3,4-d]pyrimidine derivatives.