Tetrahedron

Straightforward transformation of isoxazoles into pyrazoles: renewed and improved

SI Sviridov, AA Vasil'ev, SV Shorshnev

Index: Sviridov, Sergey I.; Vasil'ev, Andrei A.; Shorshnev, Sergey V. Tetrahedron, 2007 , vol. 63, # 49 p. 12195 - 12201

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Citation Number: 29

Abstract

Isoxazoles bearing alkyl or carbamoyl groups were transformed into the corresponding pyrazoles in high yields by the treatment with hydrazine in methanol in the presence of a hydrogenation catalyst, eg, Raney nickel, at ambient temperature. For the synthesis of N- substituted pyrazoles, hydrogenolysis of isoxazole followed by the treatment with substituted hydrazine was required. 3 (5)-Aryl-or acylamido-substituted isoxazoles are less suitable ...

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