Benzimidazole-2-carbonitrile oxide

The photoaddition reaction of 2-phenylbenzimidazole with Michael acceptors was investigated <96JHC1031> as was the preparation and cycloaddition-reactivity of benzimidazole-2-carbonitrile oxide <96AJC199>. The nitration of 1-methylbenzimidazole was found to give only the 5- and 6-nitrated products as a mixture of isomers in 87% yield... 

Azido-3-methylquinoxaline 1,4-dioxide (293) underwent thermolytic ring contraction with loss of N2 to give a separable mixture of 2-methyl-3//-benzimidazole-2-carbonitrile 1,3-dioxide (294) and its rearrangement product, 3-methyl-3//-2,l,4-benzoxadiazine-3-carbonitrile 4-oxide (295) (PhH, reflux, 10 min 46% and 41%, respectively) the latter product (295) was also obtained from the benzimidazole (294) (PhH, reflux, 30 min 76%) or from the quinoxaline (293) (PhMe, 90°C, 30 min 94%). ... 

Brasche and Buchwald developed an efficient Cu(OAc)2-catalyzed substituted benzimidazoles and substituted Af-methyl-2-arylbenzimidazoles synthesis from readily available amidines in good to very good yields (Scheme 8.50). This transformation proceeds via direct C-H bond functionalization and C-N bond formation. The O2 was used as the oxidant and water was generated as the only by-product. The starting material amidines were prepared easily from anilines with carbonitrile derivative in advance [89]. 

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