Dipolar Cycloaddition of Ethyl Isocyanoacetate to 3-Chloro-2-(methylthio)/2-(methylsulfonyl)quinoxalines: Highly Regio- and Chemoselective Synthesis of Substituted Imidazo[1,5-<i>a</i>]quinoxaline-3-carboxylates
作者:G. S. M. Sundaram、B. Singh、C. Venkatesh、H. Ila、H. Junjappa
DOI:10.1021/jo070590k
日期:2007.6.1
An efficient route for regio- and chemoselective synthesis of substituted 3-(carboethoxy)imidazo[1,5-a]quinoxalines and novel diimidazo[1,5-a:5‘,1‘-c]quinoxalines via base-induced cycloaddition of ethyl isocyanoacetate to unsymmetrically substituted 3-chloro-2-(methylthio)/2-(methylsulfonyl)quinoxalines has been reported.
通过碱诱导的环加成反应合成取代的3-(羰基乙氧基)咪唑并[1,5- a ]喹喔啉和新型二咪唑并[1,5- a:5',1'- c ]喹喔啉的区域和化学选择性合成的有效途径据报道,异氰基乙酸乙酯转化为不对称取代的3-氯-2-(甲硫基)/ 2-(甲磺酰基)喹喔啉。
Synthese primärer Nitroketenaminale
作者:Hubert Mertens、Reinhard Troschütz、Hermann J. Roth
DOI:10.1002/ardp.19863190213
日期:——
Die Titelverbindungen 3 und 4 lassen sich sowohl aus dem Nitroketen‐O,N‐acetal 1 und prim. bzw. sekund. Aminen als auch durch sukzessive Amino‐ undAmmonolyse des Nitroketen‐S,S‐acetals 2 gewinnen. Die Reaktion von 2 mit wäßrigem Ammoniak führt zum dimeren Nitroacetonitril 9.
Die Titelverbindungen 3 和 4 lassen sich sowohl aus dem Nitroketen-O,N-acetal 1 und prim。呜呜呜 塞孔德。Aminen als auch durch sukzessive Amino- und Ammonolyse des Nitroketen-S,S-acetals 2 gewinnen。Die Reaktion von 2 mit wäßrigem Ammoniak führt zum dimeren Nitroacetonitril 9.
1-Arylamino-1-methylthio-2-nitroethene in superacids: NMR study and reactivity of the formed hydroxynitrilium lons
作者:Jean-Marie Coustard
DOI:10.1016/0040-4020(96)00485-1
日期:1996.7
temperature in triflic acid, 1-arylamino-1-methylthio-2-nitroethylenes give firstly C, O-protonated species then a conjugated dication with aryliminium and hydroxynitrilium sites. The last one was trapped in situ with aromatic or quenched with MeOH or MeSH to form aryliminohydroxyimino derivatives. Intramolecular reaction occurs when temperature rises. Effect of aromatic ring substituant, acidity (HF-SbF5 5:1)
Nitroketene acetal chemistry: efficient synthesis of 2-amino-3-nitro-4H-chromenes
作者:H. Surya Prakash Rao、K. Geetha
DOI:10.1016/j.tetlet.2009.04.018
日期:2009.7
Base-catalyzed reaction of the nitroketene N,S-acetals and the ring substituted 2-hydroxybenzaldehydes afforded a combinatorial library of the 2-alkylamino-3-nitro-4-alkylsulfanyl 4H-chromenes in excellent yields. Nucleophilic displacement of the C4 alkylsulfanyl group with different thiols afforded 4H-chromenes with structural diversity. (c) 2009 Elsevier Ltd. All rights reserved.
10.4314/bcse.v29i2.11
作者:Bamba, Fanté、Soro, Yaya、Siaka, Sorho、Marrot, Jérôme、Coustard, Jean-Marie
DOI:10.4314/bcse.v29i2.11
日期:——
At low temperature in triflic acid, nitroketene S,N-acetals with a tethered phenyl ring react to form the corresponding hydroxynitrilium ions. Quenching with methanol leads to the formation of dications which undergo an unexpected Beckmann transposition affording new (E)-methyl methylsulfanyl(phenylamino) methylene carbamates.