Features and applications of reactions of α,β-unsaturated N-acylbenzotriazoles with amino compounds

Promoted by triethylamine, alpha,beta-unsaturated N-acylbenzotriazoles reacted with amino compounds in a variety of ways. Thus, N-cinnamoylbenzotriazoles reacting with aromatic amines afforded novel addition products beta-benzotriazolyl amides 3, which might be normally formed from the alternative but unknown 1,4-addition of benzotriazole to N-cinnamoylamides. The type 3 compounds could also result from the reaction between N-crotonoylbenzotriazole and aliphatic amines. However, normal 1,4-addition could occur between alpha,beta-unsaturatecl aliphatic N-acylbenzotriazoles and aromatic amines, leading to beta-amino N-acylbenzotriazoles 4 in good yields. In addition, exclusive 1,2-addition of aliphatic amines to N-cinnamoylbenzotriazoles gave excellent yields of cinnamides 5. Accordingly, three possible routes were proposed to rationalize the formation of compounds 3-5. Finally, with o-phenylenediamine and o-aminothiophenol as the substrates, the 1,4- and 1,2-addition to a, -unsaturated N-acylbenzotriazoles could take place concurrently and the Corresponding heterocycles 1,5-benzodiazepine-2-one and 1,5-benzothiazepine-4-one were constructed, respectively. (c) 2008 Elsevier Ltd. All rights reserved.