PRODUCTION OF N-SUBSTITUTED CYCLIC IMIDE

Prepn. of N-substd. cyclic imides of formula (I) comprises: (a) reaction of a cyclic anhydride of formula (II), or phthalic anhydride or a partially or fully hydrogenated phthalic anhydride with an amine of formula (III) (the molar ratio of (II) to (III) being 0.5-5:1), in the presence of a solvent, a stabiliser, an inert, dipolar aprotic cosolvent and an acid catalyst, at 80-200 degrees C, with removal of water of reaction; opt. (b) addn. of a slightly polar or non-polar organic solvent to the reaction mixt. after the reaction; (c) addn. of a non-aq. base, in amts. of 0.5-50 wt.% (based on the amt. of cpd. (II) used); and (d) sepn. of the resulting ppte., yielding a filtrate which contains cpd. (I). R1=1-20C alkyl, 3-8C cycloalkyl, 3-12C alkenyl, 7-12C aralkyl or 6-10C aryl (all opt. substd.); or a nitrile gp.; R2-R5=H; 1-12C alkyl or 2-12C alkenyl (both opt. substd.); or halo; or R2+R3 = opt. substd. 1-6C alkylene; or R3+R4 = a covalent bond; provided that at least one of the following is satisfied: (a) R2+R3 = 1-6C alkylene; (b) R3+R4=a covalent bond; (c) at least one of R2-R5 is 2-12C alkenyl.