Microwave Assisted Rapid Preparation of N-Alkyl-2-pyridones under Neutral Conditions by Hilbert-Johnson Reaction
摘要:
The reactions of 2-methoxypyridine with haloalkanes without solvent and catalyst under microwave irradiation (100-200 degrees C, 5 min) yielded the corresponding N-alkyl-2(1H)-pyridones in good to moderate yields. However, the reactions were sensitive to length of haloalkanes. In contrast, the reactions of 2-alkoxypyridines with corresponding iodoalkanes under microwave irradiation (150 degrees C) proceeded rapidly without catalyst and solvent, and were complete within 5 min to afford N-alkyl-2(1H)-pyridones in good to excellent yields.
Naggellack mit einem Gehalt an einem wasserunlöslichen Filmbildner und einem antimykotisch wirksamen Stoff der allgemeinen Formel
ist, in der R¹ einen "gesättigten" Kohlenwasserstoffrest mit 6 bis 9 Kohlenstoffatomen, einer der Reste R² und R⁴ ein Wasserstoffatom und der andere Wasserstoff, Methyl oder Äthyl und R³ einen Alkylrest mit ein oder zwei C-Atomen bedeutet, wobei diese Wirkstoffe sowohl in freier Form als auch in Form ihrer Salze zugegen sein können.
Alkylation of the 2-hydroxypyridine anion in ionic liquid media
作者:G. Vavilina、A. Zicmanis、P. Mekss、M. Klavins
DOI:10.1007/s10593-008-0074-9
日期:2008.5
The alkylation reaction of the ambident 2-hydroxypyridine anion was examined in ionic liquid media. Ionic liquids increase the alkylation reaction rate in comparison with molecular liquids, as well as the level of impact on the reaction rates of the counter ion and/or additives, and the distribution of isomers of the reaction products in trans- formations of the ambident 2-hydroxypyridine anion.
Specific N-Alkylation of Hydroxypyridines Achieved by a Catalyst- and Base-Free Reaction with Organohalides
A specific N-alkylation of 2-hydroxypyridines is achieved by reacting with organohalides under catalyst- and base-free conditions. The observed HX-facilitated conversion of pyridyl ether intermediates to 2-pyridone products may account for the success and specific N-alkylation of the reaction under the unexpectedly simple conditions. This new reaction may provide a useful alternative for the synthesis of 2-pyridones and analogous structures because of its >99% N-selectivity, relatively broad scopes of both substrates, and no mandatory use of catalysts and bases.
Microwave Assisted Rapid Preparation of N-Alkyl-2-pyridones under Neutral Conditions by Hilbert-Johnson Reaction
The reactions of 2-methoxypyridine with haloalkanes without solvent and catalyst under microwave irradiation (100-200 degrees C, 5 min) yielded the corresponding N-alkyl-2(1H)-pyridones in good to moderate yields. However, the reactions were sensitive to length of haloalkanes. In contrast, the reactions of 2-alkoxypyridines with corresponding iodoalkanes under microwave irradiation (150 degrees C) proceeded rapidly without catalyst and solvent, and were complete within 5 min to afford N-alkyl-2(1H)-pyridones in good to excellent yields.