Sheremeteva, T. V. published the artcileFormation and strength of amide and imide bonds, Category: catalysis-chemistry, the publication is Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya (1966), 695-700, database is CAplus.
cf. CA 56, 4615g. Heating aqueous solutions of the arylamides of citraconic acid results in competing reactions of cyclization to imides and hydrolysis of the amide bond; the predominance of the reactions is determined by basicity of the initial amine. The greater is the electron-acceptor ability of the amine, the more readily hydrolyzed is the amide bond and the more active is the H atom on N group; monoamides of citraconic acid formed by weak amines, such as nitroaniline, suffered mainly hydrolysis of the amide group in hot aqueous medium (72% hydrolysis in 16 hrs. at 100¡ã was noted) while cyclization to the imide was feasible only in EtOH solution (22% in 16 hrs. heating) and this reaction was facilitated by removal of H2O from the reaction mixture, so that with added P2O5 the imide yield rose to 44% in 16 hrs. heating. Amines with somewhat greater basicity (PhNH2, glycine residues) underwent cyclization to imides in aqueous solution at 100-10¡ã by 63-88% and the imide rings were relatively more stable to hydrolysis. When cyclization is inhibited by introduction of a 2nd substituent at N atom, the resulting N-amide bond is easily hydrolyzed at 100¡ã when it contains aryl and alkyl groups, while the N,N-dialkylamino group in the amides remains intact; the low level of activity of the H atom in the alkyl amides is the reason for the need to use high temperature (140-200¡ã) for cyclization of such amides. Citraconic anhydride treated with Ph-NHEt in Et2O gave in 2-3 hrs. N-ethylcitraconanilide, m. 108¡ã; similarly were prepared the N,N-dimethylamide, m. 105¡ã; anilide, m. 170¡ã; p-nitroanilide, m. 159¡ã. Citraconylaminoacetic acid in aqueous KOH was evaporated to yield 70% KO2CCH:CMeCONHCH2CO2K, m. 203-4¡ã; this with AgNO3 gave the di-Ag salt. The di-K salt above neutralized with 2N H2SO4 and heated in a sealed tube 16 hrs. at 100¡ã gave 53.3% citraconylaminoacetic acid, m. 127¡ã, as the free carboxymethylenamide of citraconic acid could not be isolated from aqueous solution owing to facile cyclization. Kinetic curves were presented for the rate of cyclization in aqueous solution and the following order of facility of imide formation was found for amides of citraconic acid (decreasing ease of cyclization): anilide, carboxymethylenamide, p-nitroanilide. Heating the anilide in H2O 16 hrs. resulted in 88% cyclization to the imide, m. 98¡ã; a kinetic curve of the reaction was shown. p-Ni-troanilide similarly treated gave a low yield of the p-nitrophenyl-imide, m. 146¡ã.
Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya published new progress about 1821-27-8. 1821-27-8 belongs to catalysis-chemistry, auxiliary class Nitro Compound,Amine,Benzene, name is Bis(4-nitrophenyl)amine, and the molecular formula is C9H7NO4, Category: catalysis-chemistry.
Referemce:
https://courses.lumenlearning.com/boundless-chemistry/chapter/catalysis/,
Catalysis – Wikipedia