(Pd/C-mediated)coupling–iodocyclization–coupling strategy in discovery of novel PDE4 inhibitors: a new synthesis of pyrazolopyrimidines†
K. Siva Kumar,Chandana L. T. Meda,G. Rajeshwar Reddy,Pradeep K. Mohakhud,K. Mukkanti,G. Rama Krishna,C. Malla Reddy,D. Rambabu,K. Shiva Kumar,K. Krishna Priya,Keerthana Sarma Chennubhotla,Rakesh Kumar Banote,Pushkar Kulkarni,Kishore V. L. Parsa,Manojit Pal
Abstract
Pyranones fused with a pyrazolopyrimidine moiety were prepared via regioselective construction of pyranone ring using (Pd/C-mediated)coupling–iodocyclization followed by Sonogashira/Heck/Suzuki reactions. The pyrazolopyrimidine based reactant required was obtained via a new H3PO3 mediated condensation reaction. This strategy has led to the discovery of a novel and potentially safe PDE4 inhibitor.
