Diisopropylamine → Tert-butyl 4-(trifluoromethanesulfonyloxy)-1,2,3,6-tetrahydropyridine-1-carboxylate

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Reaction Conditions

Reaction Steps

To a stirred solution of n-butyllithium (18.8 mL, 30.113 mmol) in THF (40.0 mL) was added diisopropylamine (4.2 mL, 30.113 mmol) at −78° C. The resulting mixture was stirred at −78° C. for 10 minutes. 4-Oxo-piperidine-1-carboxylic acid tert-butyl ester (4.000 g, 20.075 mmol), dissolved in THF (40 mL), was added to the mixture and the whole was left stirring at −78° C. for another 30 minutes. N-Phenyltrifluoromethanesulfonimide was added to the mixture at −78° C. and the solution was warmed up to room temperature over 3 hours. Ethyl acetate (200 mL) was added to the mixture and the organic phase was washed with water (100 mL), brine (100 mL), dried over MgSO4 and then concentrated in vacuo. The crude product was purified by column chromatography, eluting with a solvent gradient of 20% ethyl acetate and 80% hexane to yield the desired product, 4-trifluoromethanesulfonyloxy-3,6-dihydro-2H-pyridine-1-carboxylic acid tert-butyl ester (4.000 g, 60%).

Provenance & Evidence