N-bromobutanimide → 1,1-Dimethylethyl 4-(5-amino-6-bromo-2-pyridinyl)-1-piperidinecarboxylate

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Reaction Steps

A solution of 220 mg (0.793 mmol) 5-amino-3′,4′,5′,6′-tetrahydro-2′H-[2,4′]bipyridinyl-1′-carboxylic acid tert-butyl ester (as prepared in the previous step) in 10 mL CH2Cl2 was treated with 134 mg (0.753 mmol) N-bromosuccinimide at room temperature for 20 min. The mixture was diluted with CH2Cl2 and washed with saturated aqueous NaHCO3. The organic layer was dried over MgSO4 and concentrated in vacuo. Chromatography of the residue on a 50-g silica Varian MegaBond Elut column with 10-35% EtOAc-hexanes afforded 209 mg (74%) of the title compound as a colorless glassy solid. 1H-NMR (CDCl3; 400 MHz): δ 6.97 (d, 1H, J=8.0 Hz), 6.91 (d, 1H, J=8.0 Hz), 4.28-4.15 (br s, 2H), 4.06-3.90 (m, 2H), 2.85-2.75 (m, 2H), 2.77-2.68 (m, 1H), 1.92-1.83 (m, 2H), 1.68-1.54 (m, 2H), 1.47 (s, 9H).

Provenance & Evidence