| 摘要 |
PURPOSE:To provide a method for producing an N-nonsubstituted or substituted maleinamic acid ester from an N-nonsubstituted or substituted malelnamic acid and an alcohol simply, in a high yield and with a high selectivity. CONSTITUTION:A maleinamic acid of formula I (R<1> is H, a substituent group- containing or not containing 1-8C alkyl) is reacted with an alcohol of the formula R<2>-OH (R<2> is a 1-8C alkyl or a 3-8C cycloalkyl) in an inert solvent in the presence of a sulfonic acid-based catalyst at 0-150 deg.C, especially 20-70 deg.C to provide a maleinamic acid ester of formula II. A mixture of the compound of the formula I and at least one selected from a group consisting of sulfuric acid, sulfuric anhydride, an arylsulfonic acid and an alkylsulfonic acid or a mono(dichloro)alkylsulfuric ester of the formula III (R<3> is a 1-8C alkyl or a 3-8C cycloalkyl) is used as the sulfonic acid-based catalyst and the amount of the catalyst used is 0.01-2mol, preferably 0.1-1mol based on the maleinamic acid. |
