125867-44-9Relevant academic research and scientific papers
Improved Synthesis of 2,3-Disubstituted Pyridines by Metallation of 2-Chloropyridine: a Convenient Route to Fused Polyheterocycles
Trecourt, Francois,Marsais, Francis,Guengoer, Timur,Queguiner, Guy
, p. 2409 - 2415 (2007/10/02)
Chemoselective directed metallation of 2-chloropyridine allows the synthesis of 2-substituted 3-carbonylated pyridines, advantage being taken of the metallation ortho-directing effect of the halogen, as well as its reactivity towards nucleophiles.Thus (2-chloro-, 2-methoxy-, and 2-amino-3-pyridyl)-ethanones and -arylmethanones as well as carbaldehydes have been prepared.Some of these ortho-disubstituted intermediates have been readily cyclized to fused polyheterocycles such as naphthiridines and aza-analoges of coumarins, xanthones, and acridones.
Synthesis of ortho-substituted aminopyridines. Metalation of pivaloylamino derivatives
Estel,Linard,Marsais,Godard,Queguiner
, p. 105 - 112 (2007/10/02)
The three isomeric pivaloylaminopyridines were lithiated in more than 80% yields. Aminopyridine derivatives were treated by 2.5-3 equivalents of the complex BuLi-TMEDA at -10° in diethyl ether. Reaction of the lithiated species with various electrophiles afforded a number of ortho-substituted pivaloylaminopyridines in good yields. Secondary pyridine alcohols were oxidized to the corresponding aminopyridyl ketones. Pyridopyrimidines, benzonaphthyridines as well as an analogue of the natural antitumor alkaloid ellipticine has been synthesized showing the versatility of the method.
