New highlights of the syntheses of pyrrolo[1,2-a]quinoxalin-4-ones.
The one-pot three-component reactions of 1-substituted benzimidazoles with ethyl bromoacetate and electron-deficient alkynes, in 1,2-epoxybutane, gave a variety of pyrrolo[1,2-a]quinoxalin-4-ones and pyrrolo[1,2-a]benzimidazoles. The influence of experimental conditions on the course of reaction was investigated. A novel synthetic pathway starting from benzimidazoles unsubstituted at the five membered ring, alkyl bromoacetates and non-symmetrical electron-deficient alkynes in the molar ratio of 1:2:1, in 1,2-epoxybutane at reflux temperature, led directly to pyrrolo[1,2-a]quinoxalin-4-ones in fair yield by an one-pot three-component reaction.
Research Center Oltchim, Str. Uzinei 1, RO-240050, Ramnicu Valcea, Romania.
Emilian
E
Georgescu
C. D. Nenitzescu Centre of Organic Chemistry, Romanian Academy, Spl. Independentei 202-B, RO-060023 Bucharest, Romania ; Petru Poni Institute of Macromolecular Chemistry, Romanian Academy, Aleea Grigore Ghica Voda 41-A, RO-700487 Iasi, Romania.
Alina
A
Nicolescu
Research Dept., Teso Spec SRL, Str. Muncii 53, RO-915200 Fundulea, Calarasi, Romania.
Florentina
F
Georgescu
C. D. Nenitzescu Centre of Organic Chemistry, Romanian Academy, Spl. Independentei 202-B, RO-060023 Bucharest, Romania.
Florina
F
Teodorescu
Research Center Oltchim, Str. Uzinei 1, RO-240050, Ramnicu Valcea, Romania.
Daniela
D
Marinescu
Petru Poni Institute of Macromolecular Chemistry, Romanian Academy, Aleea Grigore Ghica Voda 41-A, RO-700487 Iasi, Romania.
Ana-Maria
AM
Macsim
C. D. Nenitzescu Centre of Organic Chemistry, Romanian Academy, Spl. Independentei 202-B, RO-060023 Bucharest, Romania ; Petru Poni Institute of Macromolecular Chemistry, Romanian Academy, Aleea Grigore Ghica Voda 41-A, RO-700487 Iasi, Romania.
Calin
C
Deleanu
1,3-dipolar cycloadditions; multicomponent; one-pot three-component reactions; pyrrolo[1,2-a]benzimidazole; pyrrolo[1,2-a]quinoxalin-4-one