172362-91-3Relevant academic research and scientific papers
2H-benzimidazoles (isobenzimidazoles). Part 10. Synthesis of polysubstituted o-phenylenediamines and their conversion into heterocycles, particularly 2-substituted benzimidazoles with known or potential anthelminthic activity
Hazelton,Iddon,Suschitzky,Woolley
, p. 10771 - 10794 (2007/10/02)
Polysubstituted o-phenylenediamines were synthesised in moderate to high yield by reductive cleavage of the corresponding 2H-benzimidazole-2-spirocyclohexane with sodium dithionite in aqueous ethanol and converted into methyl benzimidazole-2-carbamates and 2-methylthio- and 2-trifluoro-methylbenzimidazoles with known or potential anthelminthic activity. 5-(Pyrimidin-2-ylthio)-benzimidazole and 11-(pyridin-2-ylthio)dibenzo[a,c]phenazine were synthesized too. Attempts to oxidise 1,3-dihydro-2H-4,9-diazanaphth[2,3-d]imidazole, prepared by condensation of 2,3-diaminoquinoxaline with cyclohexanone, to an analogue of the title system failed.
SYNTHESIS AND REACTIONS OF 2H-BENZIMIDAZOLE-2-SPIROCYCLOHEXANES : AN APPLICATION OF "UMPOLING"
Iddon, Brian
, p. 673 - 701 (2007/10/02)
The title compounds are available through condensation of an o-phenylenediamine with cyclohexanone followed by oxidation of the resulting product with manganese dioxide.In this article we review their oxidation, reduction, and rearrangement reactions along with their reactions with nitrogen, oxygen, sulphur, and other nucleophiles.As well as the parent compound the reactions of the 5-chloro-, 5,6-dichloro-, 4,6-dibromo-, 5-phenylsulphonyl- and 5-methoxy-derivative are discussed in some detail.Some applications of the methodology developed, particularly to the synthesis of actual or potential benzimidazole anthelminthics, are given also.
