Efficient Synthesis of 1‐Arylquinoxalin‐2(1H)‐ones via Cyclocondensation of N‐Aryl‐Substituted 2‐Nitrosoanilines with Functionalized Alkyl Acetates

Abstract

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, ester, amide, and keto groups, in good to excellent yields (Tables 1–4).

Simple Synthesis of Quinoxalin‐2(1H)‐one N‐Oxides from N‐Aryl‐2‐nitrosoanilines and Alkylated Cyanoacetic Esters

“…Our attempts to synthesize 3‐cyanoquinoxalin‐2(1 H )‐ones by the reaction of N ‐aryl‐2‐nitrosoaniline with methyl cyanoacetate, following route 2 in Scheme (R = H, Y = COOMe, Z = CN) , failed. It led to multicomponent intractable mixture.…”

“…The vicinal position of nucleophilic amino—and strongly electrophilic nitroso—groups makes these compounds very interesting starting materials for domino reactions with properly equipped dipolar partners, leading to a variety of heterocyclic systems. It was already shown that reactions of title compounds with comparatively acidic sulfones (Scheme , route 1) or acetates and phosphonoacetates (Scheme , route 2) are efficient ways of synthesis of benzimidazoles and quinoxalin‐2(1 H )‐ones . Here, we would like to report a new reaction of N ‐aryl‐2‐nitrosoanilines with alkylated derivatives of cyanoacetic esters furnishing quinoxalin‐2(1 H )‐one‐4 N ‐oxides in moderate to excellent yields.…”

A Two-Step Synthesis of Selected 1,2,3,4-Tetrahydroquinoxaline Derivatives from N-Aryl-2-nitrosoanilines and Arylidenecyanoacetic Esters

“…3 Proximity and reverse philicity of the nitroso and the amino functions makes Naryl-2-nitrosoanilines interesting starting materials for the synthesis of nitrogen heterocyclic compounds. We showed their versatility for the synthesis of phenazines, 3a,4 benzimidazoles, 5 quinoxalin-2(1H)-ones, 6 or its 4-oxides. 7 Reaction of 4-amino-substituted N-aryl-2-nitrosoanilines with two molecules of esters of cyanoacetic acid led to dioxopyrroloquinoxalines.…”

Synthesis of 1-arylbenzimidazoles and dibenzo[b,e][1,4]diazepines from 2 (arylamino)aryliminophosphoranes

“…Solid products were recrystallised from hexane/ethyl acetate mixture. 1-N-Benzyl-5-bromo-1-N-(4-methylphenyl) (6). POCl 3 (0.37 mL, 4 mmol) was added dropwise to DMF (0.31 mL, 4 mmol) at ~0 ºC, and the mixture was stirred for 10 min without cooling.…”

“…The latter, bearing two differently polarized groups, proved to be valuable starting materials in the synthesis of various nitrogen heterocycles. [3][4][5][6][7][8] An attractive transformation of 2-nitrosodiarylamines appeared to be their smooth reaction with triphenylphosphine, first published in 2014, 9 leading to 2-(arylamino)aryliminophosphoranes via a Cadogan-type reaction. These turned out to be versatile and stable equivalents for 1-aryl-1,2-arylenediamines; they reacted with isocyanates, 9 nitrous acid, 10 CS 2 11 and CO 2 12 furnishing 2-aminobenzimidazoles, benzotriazoles, 2-thiobenzimidazoles and 2-benzimidazolones respectively (Scheme 1).…”