Deaminative electrochemical reduction of pyrazolo[1,5-a]pyrimidine-7-amines

Abstract

The pyrazolo[1,5-a]pyrimidine-7-amines are electrochemically reduced in hydroorganic medium at low pH into the corresponding 4,5-dihydro compounds. A mechanism is proposed featuring the intermediacy of the parent pyrazolo[1,5-a]pyrimidine itself. The 4,5-dihydroderivatives can be rearomatized, thus offering a facile synthetic route to the pyrazolo[1,5-a]pyrimidines.