4-Pyridinecarboxaldehyde → 2-[2-(4-Pyridyl)ethenyl]-1-nitrobenzene

Participants

Reaction Steps

In 120 ml of benzene was suspended 12.00 g of 2-nitrobenzyltriphenylphosphonium bromide and, under argon gas, 20 ml of 1.6M n-butyllithium/n-hexane was added dropwise under ice-cooling with care exercised so that the internal temperature would not rise beyond 20° C. The mixture was then stirred at room temperature for 2 hours, after which 3.05 g of isonicotinaldehyde was added dropwise under ice-cooling and the mixture was stirred at room temperature for another 4 hours. This reaction mixture was poured upon ice-water and extracted with ether. This extract was evaporated under reduced pressure to remove the solvent and the residue was diluted with chloroform and extracted with 2N-hydrochloric acid. The aqueous layer was made basic by adding 30% aqueous sodium hydroxide solution and extracted with chloroform. The chloroform extract was dried over anhydrous magnesium sulfate and the solvent was evaporated off. The residue was purified by silica gel column chromatography (chloroform alone) to provide 2.53 g of the title compound as tan-colored oil. This product was subjected to the next reaction without further purification.

Provenance & Evidence