Modular Synthesis of 3,6-Disubstituted-1,2,4-triazines via the Cyclodehydration of β-Keto-N-acylsulfonamides with Hydrazine Salts
Matthew S. Dowling*, Wenhua Jiao, Jie Hou, Yuchun Jiang and Shangsheng Gong
*Medicine Design, Pfizer Inc., Eastern Point Road, Groton, Connecticut 06340, United States, Email: matthew.s.dowlingpfizer.com
M. S. Dowling, W. Jiao, J. Hou, Y. Jiang, S. Gong, J. Org. Chem., 2018, 83, 4229-4238.
DOI: 10.1021/acs.joc.8b00254 (free Supporting Information)
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A redox-efficient cyclodehydration of β-keto-N-acylsulfonamides with hydrazine salts provides 3,6-disubstituted-1,2,4-triazines. The mild reaction conditions tolerate a variety of sensitive functionalities. In addition, two approaches for synthesizing the requisite β-keto-N-acylsulfonamides are presented, which allow for the late stage incorporation of either the C3 or C6 substituent in a flexible manner.
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