新法合成酰胺荚醚萃取剂

采用混合酸酐法,通过氧杂单酰胺酸与二烷基胺反应,合成了3种酰胺荚醚萃取剂N,N,N'N'-四烷基-3-氧-戊二酰胺(烷基为正丁基、异丁基和正辛基),产率分别为84%,80%和57%.采用1H NMR和MS对合成的酰胺荚醚萃取剂的结构进行了表征.

New Method for Synthesis of Amide Podand Extractants

Amide podands are a class of very promising extractants for the treatment of high level liquid wastes from nuclear industry. With the rapid development of the spent fuel reprocessing, the current synthesis methods of amide podands have hardly kept pace with the demands of surging. Therefore, it is very essential to explore a new efficient synthesis way. In this work, three amide podand extractants, N,N,N',N'-tetraalkyl-3-oxa-pentane-1,5-diamide, where the alkyl represents butyl, isobutyl and octyl, were synthesized via a mixed anhydrides method. The synthetic route includes the following three-step reaction. Diglycolic anhydride was firstly prepared through the dehydration of diglycolic acid and then reacted with the dialkyl amine to produce mono-substituted oxa-pentaneamide using pyridine as a catalyst. Finally, in the presence of isobutyl chloroformate and 4-methylmorpholine, the amide podand extractant was obtained via the reaction of mono-substituted oxa-pentaneamide with the corresponding secondary amine. Effects of carboxyl activation time and reaction temperature on the synthesis were investigated. The obtained target compounds were characterized by 1H NMR and MS. The yields of N,N,N',N'-tetrabutyl-3-oxa-pentane-1,5-diamide, N,N,N',N'-tetraisobutyl-3-oxa-pentane-1,5-diamide and N,N,N',N'-tetraoctyl-3-oxa-pentane-1,5-diamide, were 84%, 80% and 57%, respectively. From the above, the mixed anhydrides method may be used in enlarging scale of synthesis of amide podand extractants.