Synthesis of pyrazolo [1, 5??a] pyrimidines in the reaction of 5??amino??3??arylpyrazoles with methoxymethylene meldrum's acid derivatives and thermolysis of their …
Abstract A series of pyrazolo [1, 5-a] pyrimidin-3-ones 3 was prepared from Meldrum's acid and 5-amino-3-arylpyrazoles 1 by cyclization in nitrobenzene of the corresponding 5- pyrazolylaminomethylene Meldrum's acid derivatives 2. The structure of pyrazolo [1, 5-a] pyrimidin-3-ones and their precursors were determined by nmr measurements.