Acylierung von Heterocyclen mit Kohlensäurederivaten. II. Endo‐ und exo‐Carbamoylierung von 2‐Amino‐benzimidazol‐Derivaten mit Isocyanaten. Mechanismus der Acylgruppenwanderung

• Published in: Journal für Praktische Chemie
• Main Authors: Graubaum, Heinz, Martin, Dieter, Szeibert, Dagmar, Breckner, Michael, Glatt, Hans Horst, Bacaloglu, Radu, Czunderlick, Carol
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 1982
• Subjects: Carbonic acid
• Online Access: http://dx.doi.org/10.1002/prac.19823240515; http://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fprac.19823240515; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fprac.19823240515; https://onlinelibrary.wiley.com/doi/pdf/10.1002/prac.19823240515

Acylation of Heterocycles with Carbonic Acid Derivatives. II. Endo and Exo Carbamoylation of 2‐Amino‐benzimidazole Derivatives with Isocyanates. Mechanism of the Acyl Group Migration 2‐Amino‐benzimidazoles react with isocyanates with good yields to give 2‐amino‐1‐carbamoyl‐aminobenzimidazoles 1 at −30°C and the corresponding 2‐carbamoyl isomeres 2 at room temperature, respectively. The isomerization mechanism was studied by crossover experiments and kinetic measurements and has been found to consist of inter‐ and monomolecular acyl transfer.