Room Temperature ICl-Induced Dehydration/Iodination of 1-Acyl-5-hydroxy-4,5-dihydro-1<i>H</i>-pyrazoles. A Selective Route to Substituted 1-Acyl-4-iodo-1<i>H</i>-pyrazoles

A number of new functionally substituted 1-acyl-5-hydroxy-4,5-dihydro-1H-pyrazoles have been prepared in moderate to excellent 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.本研究以相应的2-炔-1-酮为起始原料，以中等至优异的产率制备了一系列新型官能团取代的1-酰基-5-羟基-4,5-二氢-1H-吡唑。所得二氢吡唑类化合物在室温下于一氯化碘（ICl）与碳酸锂（Li2CO3）的存在下发生脱水与碘化反应，从而得到1-酰基-4-碘-1H-吡唑。