1Department of Chemistry, Jawaharlal Nehru Technological University Anantapur, Ananthapuramu, Andhra Pradesh, India
2Mewar University, Gangrar, Chittorgarh, Rajasthan-312901
3Clearsynth Labs Ltd. IDA Mallapur, Nacharam, Hyderabad-500076, India
A simple, convenient and efficient method for the synthesis of 5-aryl/alkyl pyrazolo[4, 3-d]pyrimidin-7(6H)-ones from 4-amino-1-methyl-3-propylpyrazole-5-carboxamide by the condensation of aldehydes under mild and neutral reaction conditions using N-bromosuccinamide (NBS)as oxidantwith good yields and high selectivity in single step which have potential applications in medicinal chemistry.
Graphical abstract:
Pyrazolo[4, 3-d]pyrimidin-7(6H)-ones, N-Bromosuccinamide and metal free oxidative cyclisation