A process of preparing aldonamides and N-substituted aldonamides which includes the steps of recovering a by-product of the process (an ammonium salt of an aldonic acid) and converting it into at least one starting material. Aldonolactone is reacted with a primary or secondary amine and the resulting solution containing the by-product of the reaction is treated to obtain a second solution containing the starting amine and some aldonamide. Preferably, the solution is treated with a solid base to obtain a solid aldonate salt and a second solution containing the starting amine and some aldonamide. The second solution may be recycled as part of the starting material mixture. Alternatively, the amine and the aldonamide may be recovered from the second solution, and the amine alone may be recycled. The solid salt of aldonic acid may be converted into aldonic acid, which in turn may be converted into aldonolactone. The obtained aldono-1,5-lactone may also be utilized as a starting ingredient in the synthesis according to the present invention.
一种制备醛酰胺和 N-取代醛酰胺的工艺,包括回收该工艺的副产物(醛酸的
铵盐)并将其转化为至少一种起始原料的步骤。将醛内酯与
伯胺或仲胺反应,并对含有反应副产物的溶液进行处理,以获得含有起始胺和一些醛酰胺的第二种溶液。最好是用固体碱处理溶液,得到固体醛酸盐和含有起始胺和一些醛酰胺的第二种溶液。第二种溶液可作为起始原料混合物的一部分循环使用。或者,可以从第二种溶液中回收胺和醛酰胺,仅回收胺。醛酸的固体盐可以转化成醛酸,醛酸又可以转化成醛内酯。获得的醛酮-1,
5-内酯也可用作本发明合成的起始原料。