Carboxamides are prepared in high yields by dehydration condensation between nearly equimolar amounts of free carboxylic acids and amines both of which involve secondary or tertiary alkyl substituted ones with O,O'-di(2-pyridyl) thiocarbonate, a coupling reagent, in the presence of a catalytic amount of 4-(dimethylamino)pyridine.
通过在存在催化剂4-(二甲氨基)吡啶的情况下,使用耦合试剂O,O'-二(2-吡啶基)硫代碳酸酯,在几乎等摩尔量的自由羧酸和胺之间进行脱水缩合,可以高产率地制备羧酰胺,其中羧酸和胺均为次级或三级烷基取代物。