Iodine-Catalyzed Regioselective Sulfenylation of 4H-Pyrido[1,2-a]pyrimidin-4-ones with Sulfonyl Hydrazides
作者:Shaohua Wang、Wenjie Liu、Zhihao Cai、Ziying Li、Jianwen Liu、Anda Wang
DOI:10.1055/s-0036-1588549
日期:2018.1
A simple and efficient method for direct sulfenylation of 4H-pyrido[1,2-a]pyrimidin-4-ones with sulfonyl hydrazides has been developed. The transformation is catalyzed by iodine under metal-free conditions with high regioselectivity and good functional-group tolerance.
A direct C-3 alkenylation of 2-methyl-4H-pyrido[1,2-a]pyrimidin-4-ones through palladium-catalyzed C–H activation usingoxygen as the terminal oxidant has been developed. This method provides an easy access to functionalized new 2-methyl-4H-pyrido[1,2-a]pyrimidin-4-one derivatives.
已经开发了通过使用氧作为末端氧化剂的钯催化的CH活化,可以使2-甲基-4 H-吡啶[1,2- a ]嘧啶-4-酮直接进行C-3烯基化反应。该方法提供了容易获得功能化的新的2-甲基-4 H-吡啶并[1,2 - a ]嘧啶-4-酮衍生物的方法。
2-Styryl-4H-pyrido(1,2-a)pyrimidin-4-ones
申请人:E. R. Squibb & Sons, Inc.
公开号:US03935197A1
公开(公告)日:1976-01-27
2-Styryl-4H-pyrido[1,2-a]pyrimidin-4-ones having the formula ##SPC1## Wherein R.sub.1 is aryl; R.sub.2 and R.sub.3 are the same or different and are hydrogen or alkyl; and R.sub.4, R.sub.5 and R.sub.6 are the same or different and are hydrogen or methyl, have useful hypotensive activity.
Provided are a compound represented by general formula (I), or the pharmaceutically acceptable salt thereof,
(wherein R
a
represents a hydrogen atom or the like, R
1
and R
2
may be the same or different, and each represents a hydrogen atom, optionally substituted lower alkyl or cycloalkyl, or R
1
and R
2
are combined together with the adjacent nitrogen atom thereto to form nitrogen-containing heterocyclic group, and Z represents a bicyclic heterocyclic group in which optionally substituted two six-membered rings are fused to each other, or the like) and the like.
Catalyst‐ and Oxidant‐Free Electrochemical Regioselective Halogenation and Trifluoromethylation of 4<i>H</i>‐Pyrido[1,2‐<i>a</i>]pyrimidin‐4‐ones
作者:Meiyun Su、Lina Guo、Peiyu Mao、Meng Xiao、Wenjie Liu、Shaohua Wang
DOI:10.1002/ejoc.202300268
日期:2023.8
halogenation and trifluoromethylation of 4H-pyrido[1,2-a]pyrimidin-4-ones with cheap and commercially available sodium salts have been developed under external oxidant-free conditions. The reaction shows broad scope of substrates, high regioselectivity, and good functional group compatibility. Importantly, the electrosynthesis of 4H-pyrido[1,2-a]pyrimidin-4-ones represents a green and advantageous alternative
已开发出在无外部氧化剂的条件下用廉价且市售的钠盐进行 4 H-吡啶并[1,2- a ]嘧啶-4-酮的无催化剂电化学卤化和三氟甲基化。该反应显示出底物范围广、区域选择性高、官能团相容性好。重要的是,4 H-吡啶并[1,2- a ]嘧啶-4-酮的电合成代表了传统合成方法的绿色且有利的替代方法。