Facile Syntheses of New Pyrazolo[1,5-a] pyrimidines Derivatives via Reactions of Enaminones with Aminopyrazole

Abstract

Abstract: Ethyl 7-aryl-2-benzylthiopyrazolo [1,5-a] pyrimidine-3-carboxylates (3a-3f) were conveniently synthesized through the reactions of enaminones with 5-amino-3-benzylthio-4-ethoxycarbonyl-1H-pyrazole in good yields and high regioselectivity.The structures of the new compounds were fully characterized by spectroscopic measurments, elemental analysis and X-ray diffraction analysis.A plausible reaction mechanism for the formation of the title compounds was also presented.

Key words: Pyrazolo[1,5-a]pyrimidine, Enaminone, Synthesis, Mechanism, Crystal structure

LI Ming, WANG Shu-wen, WEN Li-rong, KE Zi-qin. Facile Syntheses of New Pyrazolo[1,5-a] pyrimidines Derivatives via Reactions of Enaminones with Aminopyrazole[J]. Chemical Research in Chinese Universities, 2005, 21(6): 663-667.

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