Theoretical study of N-(o-aminophenyl amic) acid cyclodehydration to 1,2-benzoilenebenzimidazole as a model reaction of ladder polypyrrones synthesis: thermodynamic and thermochemical data

The mechanism of polyimidazopyrrolones formation was studied via thermodyna mic simulation of N-(o-aminophenyl)amic acid cyclodehydration to 1,2-benzoy lenebezimidazole. It was found that 2-(o-carboxyphenyl)benzimidazole and N- (o-aminophenyl)phthalimide were the most thermodynamically favorable interm ediates of this process. The thermodynamic possibility of 1,2-benzoylenebez imidazole formation from N-(o-acetamidophenyl)phthalimide and N-(o-trifluor oacetamidoghenyl)isophthalimide was also evaluated using the same method. A ll thermodynamic values were obtained from semiempirical quantum mechanics calculations. (C) 1999 Elsevier Science B.V. All rights reserved.