| 摘要 |
PURPOSE:To obtain a benzimidazole useful as a heat-resitant material, coating compound, epoxy curing agent, adhesive, etc. under mild conditions in high yield, by reacting an aldehyde with a polyamine in the presence of a protonic catalyst. CONSTITUTION:An aldehyde such as formalin, acetaldehyde, benzaldehyde, etc. is reacted with a diamine such as o-arylenediamine, etc. to give a compound having a benzimidazole skeleton. The reaction is carried out in the presence of a protonic catalyst in the reaction system preferably in the presence of air or oxygen, to give advantageously the desired compound by a method wherein post-treatment is simple. A mineral acid such as hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, etc., Lewis acid such as BF3, etc. or an organic acid such as acetic acid, phenol, etc. which is reacted with water, etc. and releases substantially proton, especially mineral acid such as hydrochloric acid, etc. can be used as the catalyst. |
