Simple, Novel Synthesis for 1-Carbamoyl-lH-benzotriazole and Some of Its Analogs

Abstract

1-Carbamoyl-1H-benzotriazole (benzotriazole-1-carboxamide, 2a), an effective carbamoyl chloride substitute, and a range of its analogs can be synthesized in good yields in two very simple steps from 1,2-diaminobenzene. The facile preparation of the intermediate o-aminophenylurea is key to this process. A preliminary study of the reactivity of 2a has shown that once in solution in tetrahydrofuran (THF), the 1-carbamoyl isomer equilibrates to give a mixture of both 1- and 2-isomers. If the solvent is ethanol or water, equilibration occurs rapidly compared to the ultimate formation of solvolysis products.

Keywords:

• Aminophenylthioureas
• aminophenylureas
• benzotriazole-1-carboxamide
• thioureas
• ureas

ACKNOWLEDGMENT

The authors acknowledge the contributions of Perdip Singh Bahia and Jon Northall who, while students at the University of Wolverhampton, carried out and recorded significant experiments related to the current submission. This work was conducted as part of their MSc and BSc programs, respectively.