One-step reaction leading to new pyrazolo[1,5-a]pyrimidines by condensation of 2-pyrone with 5(3)-amino-3(5)-arylpyrazoles
作者:Ibtissam Bassoude、Sabine Berteina-Raboin、Jean-Michel Leger、Christian Jarry、El Mokhtar Essassi、Gérald Guillaumet
DOI:10.1016/j.tet.2011.01.070
日期:2011.3
Condensation of 5(3)-amino-3(5)-arylpyrazoles with 4-hydroxy-6-methylpyran-2-one leads to 5,7-dimethyl-2-arylpyrazolo[1,5-a]pyrimidines, 5-alkoxycarbonylmethyl-7-methyl-2-arylpyrazolo[1,5-a]pyrimidines and their isomeric 7-alkoxycarbonylmethyl-5-methyl-2-arylpyrazolo[1,5-a]pyrimidines. These compounds result from competitive reactions and from different cyclization pathways. Structure and mechanism of formation of these new products are reported. (C) 2011 Elsevier Ltd. All rights reserved.