Simple Synthesis of 2-Aminoaryliminophosphoranes from N-Aryl-2-nitrosoanilines and Their Application in 2-Aminobenzimidazole Synthesis
摘要:
Condensation of N-aryl-2-nitrosoanilines with triphenylphosphine leads efficiently to substituted aryliminophosphoranes which, in turn, react with alkyl isocyanates furnishing 2-alkylaminobenzimidazole derivatives in high yields.
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
Reaction of N-aryl-2-nitrosoanilines with alkyl arylidenecyanoacetates in the presence of Et3N in MeCN leads to substituted 1,2,3,4-tetrahydroquinoxaline derivatives in reasonable yields. The reaction comprises nucleophilic addition of the nitrosoaniline to the Michael acceptor followed by cyclization involving the nitroso group. Since the reactive nitrogen groups in N-aryl-2-nitrosoanilines are
Simple Synthesis of Quinoxalin-2(1<i>H</i>)-one<i>N</i>-Oxides from<i>N</i>-Aryl-2-nitrosoanilines and Alkylated Cyanoacetic Esters
作者:Magdalena Królikiewicz、Zbigniew Wróbel
DOI:10.1002/jhet.1947
日期:2014.1
N‐Aryl‐2‐nitrosoanilines, available from the reaction of N‐arylamines with nitroarenes, condense under alkaline conditions with alkylated derivatives of cyanoacetic esters furnishing quinoxalin‐2(1H)‐one N‐oxides in good to excellent yields. The reaction involves the condensation of the carbanion with the nitroso group leading to the nitrone intermediate, followed by intramolecular acylation of the
A Short Preparation of Pyrroloquinoxalinones via a Cascade Reaction of N-Aryl-5-alkylamino-2-nitrosoanilines with Methyl 2-Cyanoalkanoates: Unexpected Direction of Nucleophilic Substitution of Hydrogen
N-Aryl-2-nitrosoanilines possessing 5-alkylamino groups undergo a bisheteroannulation reaction with anions of 2-cyanoalkanecarboxylates resulting in pyrroloquinoxalinone derivatives. The cascade reaction involves condensation of the cyanoester anions with the nitroso group, unusual nucleophilic substitution of hydrogen in the nitrosoaniline-derived intermediate with the second carbanion molecule, and double intramolecular acylation of the amino functions.
Synthesis of 2-Alkylidene-3-acylquinoxalines from N-Aryl-2-nitrosoanilines and 1,3-Diketones
作者:Zbigniew Wróbel、Adam Trawczyński
DOI:10.1055/s-0034-1379238
日期:——
In the reaction of N-aryl-2-nitrosoanilines with -diketones, a condensation of the nitroso group with diketone carbanion followed by condensation of the amino function with the less crowded carbonyl group leads to 2-alkylidene-3-acyl-1,2-dihydroquinoxalines under mild basic conditions.