Eine neue Synthese von Benzimidazol-Derivaten,10.1002/cber.19360691010,European Journal of Inorganic Chemistry,Rudolf Weidenhagen

• ...Methods of benzimidazoles synthesis include the condensation of o-aryldiamines with carboxylic acids or their derivatives in the presence of strong acids such as polyphosphoric acid^{[ 3 ]} or mineral acids^{[ 4 ]} and the thermal or acid promoted cyclization of N-(N-arylbenzimidoyl)-1,4-benzoquinoneimines,^{[ 5 ]} the condensation of o-aryldiamines and aldehyde in refluxing nitrobenzene,^{[ 6 ]} or using various catalyst, such as Sc(OTf)₃,^{[ 7 ]} Yb(OTf)₃,^{[ 8 ]} copper(II) acetate,^{[ 9 ]} DDQ,^{[ 10 ]} I₂/KI/K₂CO₃/H₂O,^{[ 11 ]} oxalic acid,^{[ 12 ]} L-proline,^{[ 13 ]} MW,^{[ 14 ]} M(HSO₄)_n,^{[ 15 ]} and SiO₂-ZnCl₂...

Min Lei, et al. One-Pot Synthesis of 1H-Benzimidazole Derivatives Using Thiamine Hydro...