Tetrahedron letters

Synthesis of hydroxypyrazoles and 1-methyl-3-isoxazolones via haloform reactions

…, N Zanatta, A Rosa, S Brondani, MAP Martins

Index: Flores, Alex F.C.; Zanatta, Nilo; Rosa, Adriano; Brondani, Sergio; Martins, Marcos A.P. Tetrahedron Letters, 2002 , vol. 43, # 28 p. 5005 - 5008

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Citation Number: 51

Abstract

The synthesis of a new series of hydroxypyrazoles (2a–f) and 2-methyl-3-isoxazolones (3a– d) from the cyclocondensation reaction of trichloromethyl-substituted 1, 3-dielectrophiles (1a– f) with dry hydrazine and N-methylhydroxylamine is reported. The regiospecific cyclocondensation took place with the elimination of the trichloromethyl group in a haloform type reaction when acetonitrile under basic medium was used. The structure of ...