Phosphorus oxychloride → 2-(4-Methylphenyl)-6-chloromethylpyridine

Reaction equation

[CH3:1][C:2]1[CH:7]=[CH:6][C:5]([C:8]2[CH:13]=[CH:12][CH:11]=[C:10]([CH3:14])[N+:9]=2[O-])=[CH:4][CH:3]=1.P(Cl)(Cl)([Cl:18])=O>C(Cl)(Cl)Cl.C(N(CC)CC)C>[CH3:1][C:2]1[CH:7]=[CH:6][C:5]([C:8]2[CH:13]=[CH:12][CH:11]=[C:10]([CH2:14][Cl:18])[N:9]=2)=[CH:4][CH:3]=1

Participants

Procedure

To a solution of 2-(4-methylphenyl)-6-methylpyridine-N-oxide (2.8 g) in 1.0 ml of chloroform was added simultaneously phosphorus oxychloride (1.48 ml) in 10 ml of chloroform and triethylamine (2.22 ml) in 10 ml of chloroform, over a period of 15 minutes. An exothermic reaction took place initially, and then the mixture was refluxed for a further 30 minutes. The mixture was then cooled, washed with ice-water, the solvent evaporated under reduced pressure, and the residue flash-chromatographed on silica gel, eluting with 33% methylene chloride in heptane, to yield 1 g of 2-(4- methylphenyl)-6-chloromethylpyridine, m.p. 94° C.