A Simple and Efficient Synthesis of Alkyl (2-Nitroaryl)acetates and Alkyl 2-(2-Nitroaryl)propanoates via Vicarious Nucleophilic Substitution of Hydrogen in Nitroarenes by Carbanions or Alkyl Chloroacetates of Alkyl 2-Chloropropanoates
Efficient Synthesis of 1-Arylquinoxalin-2(1<i>H</i>)-ones<i>via</i>Cyclocondensation of<i>N</i>-Aryl-Substituted 2-Nitrosoanilines with Functionalized Alkyl Acetates
N‐Aryl‐substituted 2‐nitrosoanilines (=2‐nitrosobenzenamines) 1, readily available by nucleophilic substitution of the ortho‐H‐atom in nitroarenes with arenamines, react with 2‐substituted acetic acid esters in the presence of a weak base giving 1‐arylquinoxalin‐2(1H)‐ones (Scheme 2). This cyclocondensation allows for the synthesis of compounds 2–4, unsubstituted at C(3) or substituted by alkyl, aryl
Base-mediated Reaction of Quaternary Ammonium Salts with Nitroarenes - Their Useful Functionalization via Vicarious Nucleophilic Substitution (VNS)
作者:Andrzej Jończyk、Anna Kowalkowska
DOI:10.1055/s-2002-23546
日期:——
Ammonium ylides generated from ammonium salt 1a-e with a base react with derivatives of 3-nitropyridine 2a-c and 2-nitrothiophene (3) to form products of vicarious nucleophilic substitution (VNS) 7, 8, or 9 respectively. The products of VNS 10, 11, or 12 are also produced from the corresponding ammonium salts, a base and 4-chloro-nitrobenzene (4), nitrobenzene (5), or 1-nitronaphthalene (6), respectively. In a few products, an exchange of alkoxy group 7c or substitution of chlorine by alkoxyl 8a,b occured.