1187954-75-1Relevant academic research and scientific papers
Benzimidazoles and related heterocycles : 8. Acid-catalyzed rearrangement of 3-aryl-1′H-spiro[2-pyrazoline-5,2′-quinoxalin]- 3′(4′H)-ones as a new efficient method for the synthesis of 2-(pyrazol-3-yl)benzimidazoles
Mamedov,Murtazina,Gubaidullin,Khafizova,Rizvanov,Litvinov
, p. 1645 - 1655 (2010)
3-Aryl-1′H-spiro[2-pyrazoline-5,2′-quinoxalin] -3′(4′H)-ones, easily available by the reaction of 3-(2-aryl-2-oxoethylidene)-3,4-dihydroquinoxalin-2(1H)-ones with hydrazine hydrate (and phenylhydrazine), in boiling acetic acid undergo new acid-catalyzed rearrangement with the contraction of pyrazine ring of the quinoxaline system to form 2-(pyrazol-3-yl)benzimidazoles. Possible mechanisms of this rearrangement are considered.
Efficient synthesis of 2-(pyrazol-3-yl)benzimidazoles from 3-arylacylidene-3,4-dihydroquinoxalin-2(1H)-ones and hydrazine hydrate via a novel rearrangement
Mamedov, Vakhid A.,Murtazina, Anna M.,Gubaidullin, Aidar T.,Hafizova, Elena A.,Rizvanov, Il'dar Kh.
experimental part, p. 5186 - 5189 (2009/12/06)
A highly efficient method for the synthesis of 2-(pyrazol-3-yl)benzimidazoles has been developed on the basis of the novel ring contraction of 3-arylacylidene-3,4-dihydroquinoxalin-2(1H)-ones with hydrazine hydrate.
