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Highly Regioselective Synthesis of 1-Aryl-3,4,5-Substituted Pyrazoles

Francis Gosselin*, Paul D. O'Shea, Robert A. Webster, Robert A. Reamer, Richard D. Tillyer, Edward J. J. Grabowski

*Department of Process Research, Merck Frosst Centre for Therapeutic Research, 16711 route transcanadienne, Kirkland, Québec, H9H 3L1, Canada, Email:

F. Gosselin, P. D. O'Shea, R. A. Webster, R. A. Reamer, R. D. Tillyer, E. J. J. Grabowski, Synlett, 2006, 3267-3270.

DOI: 10.1055/s-2006-956487


A highly regioselective synthesis of 1-aryl-3,4,5-substituted pyrazoles based on the condensation of 1,3-diketones with arylhydrazines proceeds at room temperature in N,N-dimethylacetamide and furnishes pyrazoles in good yields.

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Key Words

1,3-diketones, arylhydrazines, pyrazoles, cyclocondensation, regioselectivity, amide solvents

ID: J60-Y2006-4790