High throughput synthesis of pyrazolopyrimidines via copper- catalysed cyclization and x-ray study

摘要

A rapid and easy high-yielding synthesis of pyrazolopyrimidinones in the presensce of copper chloride is described.To fully confirm the structure of a Viagra~R intermediate,the X-Ray structure of 5-(2-ethoxyphenyl)-l-methyl-3-propyl-l,6-dihydropyrazolo[4,3-d]pyrimidin-7-one (2a) was determined.