A mild, simple and efficient method has been developed for the promotion of the preparation of N,Nʹ-diphenylformamidines from various aromatic amines and ethyl orthoformate using sulfonated rice husk ash (RHA-SO3H) solid acid catalyst. This reagent has also been used for the N-formylation of a variety of amines using formic acid under solvent-free conditions. The procedures gave the products in very short reaction times and good-to-high yields. Also this catalyst can be reused for five times without loss of its catalytic activity.
开发了一种温和、简单、高效的方法,用于促进使用磺化稻壳灰(RHA-SO3H)固体酸催化剂,由各种芳香胺和原
甲酸乙酯制备N,N′-二苯基
甲脒。该试剂还用于在无溶剂条件下使用
甲酸对多种胺进行 N-甲酰化。该程序在非常短的反应时间内产生了产物,并且产率从好到高。该催化剂还可重复使用五次而不损失其催化活性。