Keywords: arylaminofumarates, maleimide, pyrrole-2,5-dione, transamination.3-Arylaminopyrrole-2,5-dione derivatives show fungistatic [1], herbicidal, insecticidal [2], and antitumor activity [3] and are used for the treatment and/or prophylaxis of cancer as well as conditions needing inhibition of the enzyme GSK-3 (diabetes, Alzheimer disease, and acute stroke) [4].The synthesis of 3-arylaminopyrrole-2,5-diones and their 1-alkyl derivatives is based on the cyclization of arylaminofumarates with ammonia [5], treatment of maleimides with arylhydroxylamines [6], or on the reaction of 3-halo- [4,5,7,8] or 3-hydroxy-[4, 8] pyrrole-2,5-diones with arylamines. It is also known that enamines are transaminated by amines under conditions of acid or base catalysis: 1,4-bis(dimethylamino)-1,3-butadiene by aryl and alkylamines in the presence of catalytic amounts of acetic and/or hydrochloric acid [9] and 1-nitro-2-dimethylaminopropylene by ammonia and alkylamines (without acid) or arylamines in the presence of an equimolar amount of p-toluenesulfonic acid [10].We have studied the reaction of 1-alkyl-3-alkylaminopyrrole-2,5-diones with arylamines with the aim of preparing 1-alkyl-3-arylaminopyrrole-2,5-diones.It was found that 1-methyl-3-methylaminopyrrole-2,5-dione 1 does not react with aniline at a reagent ratio from 1: 1 to 1: 3 under various conditions (refluxing in methanol, heating at 100-120ºC in DMSO, or at 100ºC without solvent over 5-40 h in the absence or presence of a catalytic or an equimolar amount of acetic acid. By contrast maleimide 1 reacts rapidly with an equimolar amount of the arylamine hydrochlorides 2a-m by heating for 1 h in methanol or DMSO to give good yields of the corresponding 3-arylamino-1-methylpyrrole-2,5-diones 3a-m (Tables 1, 2). In a similar reaction 1-(2-hydroxyethyl)-3-(2-hydroxyethylamino)pyrrole-2,5-dione reacts with p-anisidine hydrochloride to give 1-(2-hydroxyethyl)-3-(p-methoxyphenylamino)pyrrole-2,5-dione (3n) (Tables 1, 2). The reaction of maleimide 1 with an equimolar amount of aniline in the presence of 15 mole % of aniline hydrochloride (refluxing in methanol for 1 h) gave a low yield (5%) of the 1-methyl-3-phenylaminopyrrole-2,5-dione 3a.

Pyrrole derivatives R 0120Synthesis of 1-Alkyl-3-arylamino-pyrrole-2,5-diones -[via transamination of 3-methylaminopyrroledione (I) or by reaction of arylaminofumarates (VI) with primary amines]. -(CHEPYSHEV*, S. V.; MAZURKEVICH, Y. N.; LEBED', O. S.; PROSYANIK, A. V.; Chem. Heterocycl. Compd. (N. Y.) 43 (2007) 7, 844-849; Ukr. State Chem. Eng. Univ., Dnepropetrovsk 49005, Ukraine; Eng.) -H. Toeppel 12-110