申请人:NIPPON SHOKUBAI CO., LTD.
公开号:EP0672650A1
公开(公告)日:1995-09-20
A process for producing an N-unsubstituted maleimide by imidating an N-unsubstituted maleamic ester through elimination of alcohol molecule and ring closure, wherein use is made of an acidic catalyst or mono(cyclo)alkyl sulfate and it is preferable to lower the alcohol concentration in the reaction mixture. When maleamic acid is reacted with an alcohol by using an inert solvent and an acidic catalyst, a mixture of maleamic with an acidic catalyst, or a mono(cyclo)alkyl sulfate, a corresponding maleamic ester is obtained. Maleamic acid is produced by the reaction of maleic anhydride with ammonia in an inert solvent, which reaction is conducted by feeding a solution of maleic anhydride in an inert solvent into a reactor and feeding ammonia gas into an open space of the reactor to cause the ammonia to be absorbed in the solution via the surface of contact of the solution with the gas.
一种通过消除醇分子和闭环将 N-未取代马来酰胺酯酰亚胺化而生产 N-未取代马来酰亚胺的工艺,其中使用了酸性催化剂或单(环)烷基硫酸盐,并且最好降低反应混合物中的醇浓度。当使用惰性溶剂和酸性催化剂、马来酰胺与酸性催化剂的混合物或单(环)烷基硫酸盐使马来酰胺酸与醇反应时,可得到相应的马来酰胺酯。马来酰胺酸是通过马来酸酐与氨在惰性溶剂中的反应生成的,该反应是通过将马来酸酐在惰性溶剂中的溶液注入反应器,并将氨气注入反应器的开放空间,使氨通过溶液与气体的接触面被溶液吸收而进行的。