A practical procedure for the selective N-alkylation of 4-alkoxy-2-pyridones and its use in a sulfone-mediated synthesis of N-methyl-4-methoxy-2-pyridone
It has been found that selective N-alkylation of 4-alkoxy-2-pyridones can be achieved under anhydrous, mild conditions with tetrabutylammonium iodide and potassium tert-butoxide being employed as the catalyst and the base, respectively. The procedure was applied to the preparation of 4-methoxy-l-methyl-2-pyridone, a valuable building block for heterocycle synthesis. (c) 2005 Elsevier Ltd. All rights reserved.
Umpolung-like Cross-coupling of Tosylhydrazones with 4-Hydroxy-2-pyridones under Palladium Catalysis
作者:Tania Katsina、Kyriaki Eleni Papoulidou、Alexandros L. Zografos
DOI:10.1021/acs.orglett.9b03119
日期:2019.10.4
Tosylhydrazones under palladium catalysis were found to perform cross-couplingreactions with 4-hydroxy-2-pyridones. The umpolung-like reactivity, between the α-carbon of tosylhydrazone and the 3-position of the heterocycle, which is observed in the obtained products, indicates the directed sp3-CH-activation of an alkylated phenol intermediate by the pendant 3-palladated heterocycle. The reaction and its intercepted