Pyridine → 4-(2-Pyridyl)benzonitrile

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Reaction Steps

A solution of 7.05 g (102 mmol) of sodium nitrite in 16 ml of water is added dropwise at 5° C. in the course of 30 min to a suspension of 11.8 g (0.10 mol) of 4-amino-benzonitrile in 40 ml of water and 36.2 ml of conc. HCl. The turbid yellow reaction solution is then added dropwise at 35-40° C. over a period of 100 min to 121 ml of pyridine. After 45 minutes' stirring at 90° C. the excess pyridine is evaporated off (RV; 60° C.), and the residue is taken up in ethyl acetate and washed with water and brine, dried (Na2SO4) and concentrated by evaporation. Column chromatography (SiO2; hexane/ethyl acetate 4:1→3:2→1:1→ethyl acetate) yields 4-(pyridin-2-yl)-benzonitrile, followed by 4-(pyrid-3-yl)-benzonitrile [1H-NMR (CDCl3) 8.86 (dd, J=2, 1, 1H), 8.68 (dd, J=5, 2, 1H), 7.89 (m, 1H), 7.79 (d, J=9, 2H), 7.69 (d, J=9, 2H), 7.43 (dd, J=8, 5, 1H)] and finally 4-(pyridin-4-yl)-benzonitrile.

Provenance & Evidence