One-Pot Synthesis of Highly Substituted Nicotinic Acid Derivatives Based on a Formylation Strategy of Enamino Keto Esters
作者:Sukeerthi Kumar、Aarti A. Sawant、Rajendra P. Chikhale、Keya Karanjai、Abraham Thomas
DOI:10.1021/acs.joc.5b02796
日期:2016.2.19
A facile one-pot synthesis of 4-chloro or 4-bromonicotinic acidesters with optional 2- and 2,5-disubstitution on the pyridine ring has been developed from easily accessible enamino keto esters by a formylation followed by in situ intramolecular cyclization strategy under optimized Vilsmeier reaction conditions. The effect of the substituents on the β-carbon and the nature of the keto functionality
Chelate synthesis of 3-ethoxycarbonyl-4-hydroxy-2-trifluoromethylpyridine from ethyl acetoacetate and trifluoroacetonitrile
作者:V. A. Dorokhov、L. S. Vasil'ev、F. E. Surzhikov、V. S. Bogdanov
DOI:10.1007/bf00700905
日期:1995.7
Ethyl 2-acetyl-3-amino-4,4,4-trifluoro-2-butenoate was synthesized by treatment of ethylacetoacetate with CF3CN in the presence of Ni(acac)2. Condensation of the diphenylboron chelate of the former with dimethylformamide dimethylacetal followed by refluxing in ethanol yielded 3-ethoxycarbonyl-4-hydroxy-2-trifluoromethylpyridine.