Tert-butyl 4-(trifluoromethanesulfonyloxy)-1,2,3,6-tetrahydropyridine-1-carboxylate → tert-butyl 3-methyl-3',6'-dihydro-2,4'-bipyridine-1'(2'H)-carboxylate

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Reaction Conditions

Reaction Steps

A solution of 4-trifluoromethanesulfonyloxy-3,6-dihydro-2H-pyridine-1-carboxylic acid tert-butyl ester (8.10 g, 24.8 mmol; Bursavich, M. G.; et al. Org. Lett. 2001, 3, 2317) in tetrahydrofuran (50 mL) was treated with 3-methyl-2-pyridylzinc bromide (0.5 M in tetrahydrofuran, 65.0 mL, Aldrich), tetrakis(triphenylphosphine)-palladium(0) (280 mg, 0.24 mmol) and the mixture heated to 70° C. for 2 hours. The mixture was cooled to room temperature, concentrated under reduced pressure, the residue taken up in dichloromethane and washed with 1N sodium hydroxide. The organic phase was dried (magnesium sulfate), filtered and concentrated under reduced pressure. The residue was purified by flash column chromatography on silica gel (elution with 50% ethyl acetate: hexanes) to provide 5.50 g (82% yield) of the title compound as a light yellow oil. 1H NMR (300 MHz, DMSO-d6) δ 1.44 (s, 9H), 2.32 (s, 3H), 2.44 (m, 2H), 3.54 (m, 2H), 3.99 (m, 2H), 5.88 (br s, 1H), 7.17 (dd, 1H, J=7.8, 4.8 Hz), 7.62 (br d, 1H, J=7.5 Hz), 8.36 (dd, 1H, J=4.8, 1.7 Hz); MS (DCI/NH3) m/e 275 (M+H)+; 292 (M+NH4)+.

Provenance & Evidence