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