Croatica Chemica Acta, Vol. 89 No. 1, 2016.
Original scientific paper
https://doi.org/10.5562/cca2738
Simple Efficient Routes for the Preparation of Pyrazoleamines and Pyrazolopyrimidines: Regioselectivity of Pyrazoleamines Reactions with Bidentate Reagents
Moustafa Sherief Moustafa
; Department of Chemistry, Faculty of Science, Kuwait University, P.O. Box 5969, Safat 13060 Kuwait
Saleh Mohammed Al-Mousawi
; Department of Chemistry, Faculty of Science, Kuwait University, P.O. Box 5969, Safat 13060 Kuwait
Mohamed Hilmy Elnagdi
; Department Chemistry, Faculty of Science, Cairo University, P.O. Box 12613 Giza – Egypt
Abstract
Simple and efficient routes for the preparation of 2-amino-5-phenyl-4,5-dihydrofuran-3-carbonitrile (12), 2-oxo-5-phenyl-tetrahydrofuran-3-carbonitrile (13) and the 3,5-diaminopyrazole derivative 2h were developed. The results of the reactivity profiles of 12 and 2h are reported and the previously investigated reaction of pyrazole-3,5-diamine (2b) with acrylonitrile to yield compound (31), a N-1 acylation product, is currently justified by using X-ray crystallographic analysis. Taken together, the observation of alkenes and alkynes substitution when reacting with 3,5-diaminopyrazole derivative 2h is explained by the terminal electron withdrawing group. This pattern of substitution is attributed to involvement of sterically unhindered electrophiles primarily at the N-1 position.
This work is licensed under a Creative Commons Attribution 4.0 International License.
Keywords
diamino pyrazoles; reduction; Michael addition; pyrazolopyrimidines; cyclic enamines
Hrčak ID:
158793
URI
Publication date:
20.6.2016.
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