Room Temperature ICl-Induced Dehydration/Iodination of 1-Acyl-5-hydroxy-4,5-dihydro-1H-pyrazoles. A Selective Route to Substituted 1-Acyl-4-iodo-1H-pyrazoles
Jesse P. Waldo, Saurabh Mehta and Richard C. Larock*
*Department of Chemistry, Iowa State University, Ames, Iowa 50011, Email: larockiastate.edu
J. P. Waldo, S. Mehta, R. C. Larock, J. Org. Chem., 2008, 73, 6666-6670.
DOI: 10.1021/jo800789p (free Supporting Information)
Various 1-acyl-5-hydroxy-4,5-dihydro-1H-pyrazoles have been prepared in good yields from the corresponding 2-alkyn-1-ones. The resulting dihydropyrazoles undergo dehydration and iodination in the presence of ICl and Li2CO3 at room temperature to provide 1-acyl-4-iodo-1H-pyrazoles.
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