An Improved Synthesis of Urea Derivatives from N-Acylbenzotriazole via Curtius Rearrangement
Anoop S. Singh, Anand K. Agrahari, Sumit K. Singh, Mangal S. Yadav, Vinod K. Tiwari*
*Department of Chemistry, Institute of Science, Banaras Hindu University, Varanasi, 22100, India, Email: Vinod.Tiwaribhu.ac.in
A. S. Singh, A. K. Agrahari, S. K. Singh, M. S. Yadav, V. K. Tiwari, Synthesis, 2019, 51, 3443-3450.
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The good leaving group ability of the benzotriazole moiety in N-acylbenzotriazoles enables a mild, metal-free synthesis of symmetric, unsymmetric, N-acyl, and cyclic ureas in good yields by treatment with TMSN3/Et3N in the presence of various amines in short reaction time. In many cases, no column chromatography is required for the purification.
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