title: Reaction for the synthesis of benzimidazol-2-ones, imidazo[5,4-b]-, and imidazo[4,5-c]pyridin-2-ones via the rearrangement of quinoxalin-2-ones and their aza analogues when exposed to enamines.
abstract: A synthetically useful protocol has been developed for the preparation of highly functionalized N-pyrrolylbenzimidazol-2-ones. The reaction of variously substituted 3-aroyl- and 3-alkanoylquinoxalin-2(1H)-ones with commercially available enamines in acetic acid results in a rapid rearrangement and formation of N-pyrrolylbenzimidazol-2-ones in modest to excellent yields. The key step of the rearrangement involves the novel ring contraction of 3-aroyl- and 3-alkanoylquinoxalin-2(1H)-ones with enamines. In this case, the atom of carbon which is displaced from the pyrazine ring of quinoxalin-2(1H)-one becomes the fourth carbon atom of the newly formed pyrrole ring. The method is applicable for the aza analogues of quinoxalin-2(1H)-ones.
authors.affiliation: A.E. Arbuzov Institute of Organic and Physical Chemistry, Kazan Scientific Center of the Russian Academy of Sciences , Arbuzov str. 8, Kazan 420088, Russian Federation.
authors.forename: Vakhid A
authors.initials: VA
authors.lastname: Mamedov
authors.forename: Nataliya A
authors.initials: NA
authors.lastname: Zhukova
authors.forename: Anastasiya I
authors.initials: AI
authors.lastname: Zamaletdinova
authors.forename: Tat'yana N
authors.initials: TN
authors.lastname: Beschastnova
authors.forename: Milyausha S
authors.initials: MS
authors.lastname: Kadyrova
authors.forename: Il'dar Kh
authors.initials: IKh
authors.lastname: Rizvanov
authors.forename: Victor V
authors.initials: VV
authors.lastname: Syakaev
authors.forename: Shamil K
authors.initials: SK
authors.lastname: Latypov
mesh_terms: D001372:Aza Compounds / Q000737:chemistry*; D001562:Benzimidazoles / Q000138:chemical synthesis* / Q000737:chemistry; D015394:Molecular Structure; D011728:Pyridones / Q000138:chemical synthesis* / Q000737:chemistry; D011810:Quinoxalines / Q000737:chemistry*; D013329:Structure-Activity Relationship
chemical_list: D001372:Aza Compounds; D001562:Benzimidazoles; D011728:Pyridones; D011810:Quinoxalines; C053110:benzimidazol-2-one