作者:Yoon-Joo Ko、Kyung-Bae Park、Seung-Bo Shim、Jung-Hyu Shin
DOI:10.1016/j.jfluchem.2006.02.009
日期:2006.6
An efficient synthesis of novel 3,5-difluoropyridine-4-carboxaldehyde using N-fluoro-benzenesulfonimide (NSFi) is described. Difluorination was achieved through the reaction of 3,5-dihalo-1,3-dioxolane pyridine with n-butyllithium followed by N-fluorobenzenesulfonimide at -120 degrees C in good to high yields. Maintaining the low temperature during the transmetallation was found to be critical for the selective formation of the difluoro-susbstitution over the monofluoro one. (c) 2006 Elsevier B.V. All rights reserved.