5577-04-8Relevant articles and documents
One-pot synthesis of multisubstituted benzimidazoles via sequential Ugi and catalytic aza-wittig reaction starting from 2-aminobenzoyl azides
Yan, Yan-Mei,Rao, Yong,Ding, Ming-Wu
, p. 1263 - 1268 (2016)
A simple and one-pot synthesis of multisubstituted benzimidazoles by a Ugi 4CC/catalytic aza-Wittig sequence was developed. The reaction of 2-aminobenzoyl azide 2, aldehyde 3, acid 4, and isocyanide 5 produced the benzimidazoles 8 in moderate to good yields via a sequential Ugi condensation and catalytic aza-Wittig in the presence of a catalytic amount of phospholene oxide.
Schmidt reaction of some constrained aromatic acids, and related topics
Ruediger, Edward H.,Gandhi, Sham S.,Gibson, Martin S.,Farcasiu, Dan,Uncuta, Cornelia
, p. 577 - 579 (2007/10/02)
Schmidt reaction of phthalic acid in 90-98percent sulfuric acid gives anthranilic acid and anthranilazide (major products) by a process considered to involve 3,1-benzoxazin-2,4(1H)-dione as intermediate.Benzimidazol-2-one is produced in this reaction by a secondary process from anthranilazide; it is also produced by photolysis of anthranilazide.Under Schmidt reaction conditions, 1,2,3-benzotriazin-4(3H)-one gives o-azidobenzamide.Under similar conditions, the lactol of 4-formyl-5-phenanthroic acid gives 1-azapyren-2(1H)-one and phenanthrene-4,5-dicarboximide, while phenanthrene-4,5-dicarboxylic acid gives 1-azapyren-2(1H)-one.Diphenic acid yields phenanthridone and 2,2'-diaminobiphenyl in proportions dependent on the sulfuric acid concentration.
