A New Approach Towards the Synthesis of Imidazol-4-Ones Using α-Diazoesters and Hydrazide Catalysed by Cu(I) Salt

Imidazole and substituted imidazoles have drawn much attention owing to their superior biological functions. In this regard, devising a synthetic strategy to improve viability, easy to handle and more yield is challenging task for synthetic chemists. Herein we report a new synthetic strategy for the synthesis of imidazol-4-ones from hydrazides and α-diazoesters using Cu(I) metal catalyst. In the absence of the Cu(I) catalyst or even utilizing any other metal catalyst, the imine bond formation between the terminal N of hydrazides and carbene was observed. The reaction proceeds via the cleavage of the C−N bond of the hydrazide followed by cyclization and yielded the expected product. We have also explored the substrate scope of our strategy and obtained excellent yields. We have isolated the products in pure form and fully characterized them using sophisticated analytical and spectroscopic techniques including single crystal X-Ray analysis.