The methods of synthesis of 2-aminobenzophenones — key precursors of 1,4-benzodiazepines

Abstract

The review article briefly presents the pharmacological profile and mechanism of action of 1,4-dibenzodiazepines, and the structures of the most important drugs from this class of compounds. The strongest emphasis is placed on presentation of various methods for the synthesis of 2-aminobenzophenones — the most often used precursors in the synthesis of 1,4-benzodiazepines and numerous classes of azaarenes. The reactions or their sequences were grouped according to retrosynthetic strategies based on structural similarities and differences of the reagents used. There were presented not only the most classical methods like Friedel-Crafts acylation or Grignard reaction, but also more advanced transformations utilizing various catalysts and more sophisticated approaches involving the synthesis of heterocyclic systems followed by their reductive or oxidative cleavage. Selected nuances of the presented reactions were discussed, including fragments of mechanisms, limitations of the applicability of a given method, and the advantages of modern solutions over the oldest and more classical methods.