DOI: 10.1021/acs.joc.6c01094 ISSN: 0022-3263
Radical Fluoroacylation of Pyrazolo[1,5- a ]pyrimidines: A Gateway to Zaleplon and Reversan Drugs
Akshay Kumawat, Yashapal Basannavar, Mary Sravani Galla, Kshirsagar Prasad Suhas, Sowmya Dastari, Nagula ShankaraiahAbstract
A site-selective fluoroacylation of pyrazolo[1,5-a]pyrimidines using tri/difluoroacetic anhydrides (DFAA/TFAA) under catalyst-free conditions was devised. This method entails a free radical-directed C–H functionalization, delivering a broad range of fluorinated pyrazolo[1,5-a]pyrimidine frameworks, which are valuable key intermediates in pharmaceutical APIs. In addition, this protocol was also applied in the concise synthesis of the zaleplon and reversan drugs.