Tetrahedron

Conjugated azoalkenes. Part XI. Direct synthesis of substituted pyrazoles and 4-triphenylphosphoranylidene-4, 5-dihydropyrazol-5-ones by heterocyclization of some …

OA Attanasi, P Filippone, A Mei

Index: Attanasi, Orazio A.; Filippone, Paolino; Mei, Amedeo Tetrahedron, 1992 , vol. 48, # 9 p. 1707 - 1714

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Citation Number: 18

Abstract

The simple and direct synthesis in good yields of substituted pyrazoles and 4- triphenylphosphoranylidene-4, 5-dihydropyrazol-5-ones is reported. These products have been prepared by heterocyclization under different reaction conditions of some 1, 5- zwitterionic species obtained from the 1, 4-conjugate addition of triphenylphosphine to the azo-ene system of conjugated azoalkenes.