A Versatile Protocol for the Synthesis of Pyrazolyl-Substituted Pyridinium and Guanidinium Salts from Pyridone and Urea Derivatives
作者:Antje K. C. Echterhoff、Sivathmeehan Yogendra、Jutta Kösters、Roland Fischer、Jan J. Weigand
DOI:10.1002/ejoc.201403057
日期:2014.12
The trication (pyr3P2)3+ (1+, pyr = 3,5-dimethylpyrazolyl) is used as a convenient pyrazolyl-transfer reagent to convert 2-pyridones, 4-pyridones, and ureaderivatives to pyrazolyl-substitutedpyridinium or guanidinium triflate salts. This conversion represents a new, efficient, and highly functional-group-compatible approach that yields the desired products conveniently and in high yields. Typically