| 摘要 |
PROCESS FOR PREPARING MONOAMIDO ACIDS There is disclosed a novel process of preparing highly pure monoamido acid by the reaction of a dibasic acid and an amine wherein a large molar excess of dibasic acid is utilized and conveniently recovered for recycle in the process to prepare additional amounts of the said monoamido acid. It has been discovered that amidation of both acid groups of the dibasic acid is held to low levels while efficiency of the reaction is maintained by recycle of unreacted starting acid. The unwanted diamido compound is separated from the desired product by first forming a water soluble salt of the monoamido acid then removing it from the insoluble diamido by-product by conventional means such as filtration. The desired monoamido acid may be recovered by acidification of the salt thereby precipitating the acid for easy recovery from an aqueous medium.
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