Heterocycles

Synthetic studies connected with the preparation of N-[3-(3-cyanopyrazolo [1, 5-a] pyrimidin-5-yl) phenyl]-N-ethylacetamide, a zaleplon regioisomer

S Radl, M Blahovcova, M Tkadlecová, J Havlicek

Index: Radl, Stanislav; Blahovcova, Michaela; Tkadlecova, Marcela; Havlicek, Jaroslav Heterocycles, 2010 , vol. 80, # 2 p. 1359 - 1376

Full Text: HTML

Citation Number: 3

Abstract

Abstract– N-[3-(3-Cyanopyrazolo [1, 5-a] pyrimidin-5-yl) phenyl]-N-ethylacetamide, a principal impurity of zaleplon, is prepared by Suzuki-Miyaura cross coupling reaction of the corresponding boronic acid and/or boronates with 5-chloropyrazolo [1, 5-a] pyrimidin-3- carbonitrile (7). Various methods of preparation of both components are described, as well as approaches based on the final modification of the 5-(3-aminophenyl)-pyrazolo [1, 5-a] ...