One-Pot Synthesis of Substituted 2-Amino Isonicotinic Acids: Reminiscent of the Guareschi-Thorpe Condensation
Xiangle Jin, Lidong Xing, Daniel Da Deng, Jun Yan, Yan Fu and Weitong Dong*
*Chemical Development, Boehringer Ingelheim Pharmaceuticals, Inc., 900 Ridgebury Road, Ridgefield, Connecticut 06877, United States
X. Jin, L. Xing, D. D. Deng, Y. Yan, Y. Fu, W. Dong, J. Org. Chem., 2022, 87, 1541-1544.
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Condensation of 2,4-dioxo-carboxylic acid ethyl esters with ethyl 3-amino-3-iminopropionate hydrochloride provides a wide variety of mono- or disubstituted 2-amino isonicotinic acids. The reaction likely proceeds through an in situ decarboxylation process.
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proposed reaction pathway