The regioselectivity in the formation of pyrazolines and pyrazoles from nitrile imines

…, NM Elwan, A Harhash, AS Shawali

文献索引：Hassaneen, Hamdi M.; Hilal, Rifaat H.; Elwan, Nehal M.; Harhash, Abdelhamid; Shawali, Ahmad S. Journal of Heterocyclic Chemistry, 1984 , vol. 21, p. 1013 - 1016

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被引用次数: 46

摘要

Abstract The 1, 3-cycloaddition of the nitrile imines 2a-e to the carbon-carbon double bond in benzalacetophenone leads to the formation of 4-phenyl-5-benzoylpyrazolines 3a-e which were converted into 4-phenyl-5-benzoylpyrazoles 5a-e upon treatment with chloranil in xylene. However, the cycloaddition of 2a-e to the carbon-carbon double bond in the enol tautomer of dibenzoylmethane gives the regioisomers 5-phenyl-5-hydroxy-4- ...