Facile Synthesis of 1, 3-Benzaoxazine Fused Triazoles Via Pd Catalysed Highly Selective Isocyanide Insertion/Cyclisation/N-N Bond Formation Cascade

Abstract

Triazoles are a significant class of N-heterocycles that are well known for their biological activities. In recent years, many advances and practices have been performed to synthesise triazole containing compounds. In this work we have demonstrated an effective protocol for the synthesis of benzoxazine fused triazoles which are known for their diuretic activities. The synthesis comprises of Pd-catalysed one pot cascade reaction involving isocyanide insertion, cyclisation and N-N bond formation from N-arylamides based hydrazones. N-aryl diazoamides are basically used in the synthesis of oxindoles but herein we have used them as starting material for the synthesis of fused triazoles. This method is really easy to carry out and to extract the product. The final product is formed in good to excellent yields with no side products leading to less chemical waste making this protocol eco-friendly.