Sodium hydride → 4-(3-ethoxycarbonyl-5-pyridin-4-yl-1H-pyrrol-2-yl)-piperidine-1-carboxylic acid tert-butyl ester

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Reaction Conditions

Reaction Steps

To a solution of 4-(2-ethoxycarbonyl-acetyl)-piperidine-1-carboxylic acid tert-butyl ester 8 (2.5 g, 8.3 mmol) in anhydrous THF (200 mL), cooled at 0° C., NaH (900 mg, 21 mmol) was added. After 15 min 2-bromo-1-pyridin-4-yl-ethanone hydrobromide 1 (3 g, 10.8 mmol) was added and the mixture was stirred 5 h at 0° C. The solvent was removed under reduced pressure and the residue was dissolved in EtOH (120 mL). Ammonium acetate (1.9 g, 25 mmol) was added and the solution was stirred overnight at rt. After solvent removal the residue was dissolved in EtOAc and the organic phase was washed with a saturated aq solution of Na2CO3, then with water, dried (Na2SO4) and concentrated. The crude material was purified by silica gel chromatography (eluant: EtOAc) to yield 4-(3-ethoxycarbonyl-5-pyridin-4-yl-1H-pyrrol-2-yl)-piperidine-1-carboxylic acid tert-butyl ester as a pink solid (1.55 g, 47%).

Provenance & Evidence