Directed lithiation of 4-halopyridines: chemoselectivity, regioselectivity and application to synthesis was written by Marsais, F.;Trecourt, F.;Breant, P.;Queguiner, G.. And the article was included in Journal of Heterocyclic Chemistry in 1988.Product Details of 116922-60-2 This article mentions the following:
The title pyridines I (R = Cl, F, R1 = H) were ortho-lithiated with BuLi-N,N,N‘,N‘-tetramethylethylenediamine or LiN(CHMe2)2 and treated with electrophiles, e.g. MeI, Me3SiCl, and PhCHO, to give 3,4-disubstituted pyridines I [R = Cl, F, R1 = Me, Me3Si, Ph(OH)CH], resp. Oxidation of I [R = F, R1 = Ph(HO)CH] with MnO2 followed by ammonolysis with NH3-EtOH gave ketone II. Annulation of II with cyclohexanone gave 1,6-naphthyridine III. Lithiation of I (R = F, R1 = H) at low temperature followed by warming gave 3,4-pyridyne which was trapped by cycloaddition with furan to give adduct IV. In the experiment, the researchers used many compounds, for example, 3-Bromo-4-fluoropyridine (cas: 116922-60-2Product Details of 116922-60-2).
3-Bromo-4-fluoropyridine (cas: 116922-60-2) belongs to pyridine derivatives. Pyridine has a conjugated system of six π electrons that are delocalized over the ring. The molecule is planar and, thus, follows the Hückel criteria for aromatic systems. Several pyridine derivatives play important roles in biological systems. While its biosynthesis is not fully understood, nicotinic acid (vitamin B3) occurs in some bacteria, fungi, and mammals.Product Details of 116922-60-2