2,4,6-Trimethylpyridine → 1-(2-Nitrophenyl)-1,2,3,4-tetrahydroquinoline

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Reaction Steps

A stirred mixture, under nitrogen of 70.6 g (0.50 mole) of 1-fluoro-2-nitrobenzene, 133.2 g (1.00 mole) of 1,2,3,4-tetrahydroquinoline and 121.2 g (1.00 mole) of symmetrical collidine in 500 ml of 1,2,3-trimethylbenzene was refluxed (bp 178°) for 5 days. The mixture was concentrated in vacuo. The residue was taken up in 1000 ml of chloroform and extracted with 500 ml of 2N-hydrochloric acid. The aqueous phase was back extracted with 250 ml of chloroform. The combined organic layers were washed 3 times with 2N-hydrochloric acid, once with 2N-sodium hydroxide solution, twice with water and dried over anhydrous sodium sulfate. The solvent was removed in vacuo. The residual oil was dissolved in 300 ml of 1:1 hexane:toluene and adsorbed on a chromatography column containing 2 kg of silica gel packed in hexane. Elution with 1:1 hexane:toluene gave fractions containing product. The fractions were combined and concentrated to afford 28.2 g (22%) of product. Recrystallization from hot isopropyl ether afforded the analytical sample, mp 69°-71° C.

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