A facile environment-friendly one-pot two-step regioselective synthetic strategy for 3,7-diarylpyrazolo[1,5- a]pyrimidines related to zaleplon and 3,6-diarylpyrazolo[1,5- a]pyrimidine-7-amines assisted by KHSO $$_{4}$$ in aqueous media.

Autor: Devi, Asem, Kaping, Shunan, Vishwakarma, Jai
Zdroj: Molecular Diversity; Nov2015, Vol. 19 Issue 4, p759-771, 13p
Abstrakt: 3-Aminopyrazoles required for the synthesis of pyrazolo[1,5- a]pyrimidines were obtained by the reaction of enaminonitriles with hydrazine hydrate. The resulting aminopyrazoles are reacted with formylated acetophenones under reflux at $$60~ ^\circ \hbox {C}$$ assisted by KHSO $$_{4}$$ in aqueous media to form regioselectively 3,7-diarylpyrazolo[1,5- a]pyrimidines and 3,6-diarylpyrazolo[1,5- a]pyrimidine-7-amines. X-ray crystallography of selected compounds 5b and 7i further confirmed the regioselective formation of these products. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index
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