Figure 16.5 Examples of agrochemical pyridine derivatives and their applications.1434j 16 Six-Membered Heterocycles: Pyridines
IR DataThe pyridine IR spectrum is quite similar to the corresponding vibrations of benzene. Pyridine has C-H stretching frequencies in the range 3020-3070 cm À1 as well as C¼C and C¼N stretching frequencies at 1590-1660 cm À1 and near 1500 cm À1 . N J 2,3 = 4-6 J 2,4 = 0-2.5 J 2,5 = 0-2.5 2 3 4 5 6 J 2,6 = 0-0.6 J 3,4 = 7-9 J 3,5 = 0.5-2 1436j 16 Six-Membered Heterocycles: Pyridines R + Metal catalyst ∆ R = alkyl, vinyl, aryl Scheme 16.2 16.