2(1H)-Pyrazinone, which is in equilibrium with 2-pyrazinol, reacts with benzonitrile oxide (BNO) affording the N-1-adduct with a 67% yield, while 2-methoxypyrazine gives two methoxypyrazinones (ca. 3%) and a biscycloadduct together with its degradation product, which derive from the two unisolable monocycloadducts to the C=N-4 double bond. N-Methylpyrazinone gives only the degradation product (3.4%) of the initial monocycloadduct of BNO to C=N-4 doable bond.
Dutcher, Journal of Biological Chemistry, 1947, vol. 171, p. 321,324
作者:Dutcher
DOI:——
日期:——
[3+2] Cyclization of Azidotrimethylsilane with Quinoxalin-2(1<i>H</i>
)-Ones to Synthesize Tetrazolo[1,5-<i>a</i>
]quinoxalin-4(5<i>H</i>
)-Ones
protocol for the synthesis of thetetrazolo[1,5‐a]quinoxalin‐4(5H)‐ones via copper‐catalyzed [3+2] cyclization of azidotrimethylsilane with quinoxalin‐2(1H)‐ones under mild conditions has been disclosed. This practical protocol is compatible with a variety of functional groups and provides an access to functionalized tetrazolo[1,5‐a]quinoxalin‐4(5H)‐ones from readily available and safe starting materials
一种方便有效的方案,在温和的条件下,用喹喔啉-2(1 H)-1通过铜催化的叠氮三甲基硅烷的[ 3 + 2]环化反应合成四唑并[1,5 - a ]喹喔啉-4(5 H)-1。条件已经公开。该实用协议与各种官能团兼容,并提供了从容易获得的安全起始原料中获得功能化四唑[1,5 - a ]喹喔啉-4(5 H)-的方法。
Chemoselective methylation of amides and heterocycles using chloromethyldimethylsilyl chloride
作者:Alan R Bassindale、David J Parker、Pravin Patel、Peter G Taylor
DOI:10.1016/s0040-4039(00)00731-0
日期:2000.6
with an amide generates a pentacoordinate N-(amidomethyl)-halosilane that can be desilylated with cesium fluoride to give the N-methyl amide. This provides a selective method for the monoalkylation of amides in the presence of other, more nucleophilic groups.