Carbon Dioxide → 1,1-Dimethylethyl 4-[3-[(4-methoxyphenyl)methyl]-1,2,4-oxadiazol-5-yl]-1-piperidinecarboxylate

Participants

Reaction Conditions

Reaction Steps

1-(tert-Butoxycarbonyl)piperidine-4-carboxylic acid (2.29 g, 10.0 mmoles) in 10 mL DMF was treated with 1,1′-carbonyldiimidazole (1.62 g, 10 mmoles, 1 eq.) at ambient temperature for 30 min until CO2 evolution ceased. (1Z)-N′-hydroxy-2-(4-methoxyphenyl)ethanimidamide [J. Med. Chem., 36(11), 1529 (1993)] (10.0 mmoles, 1 eq.) was dissolved in 5 mL DMF and added to the reaction mixture. The reaction mixture was heated at 70° C. for 6 h then at 120° C. for an additional 6 h. The reaction mixture was diluted with EtOAc and washed successively with water, 1N citric acid, saturated aqueous NaHCO3, and brine. The organic phase was isolated, dried over MgSO4, filtered and concentrated to give the title compound as an amber oil. 1H NMR (300 MHz, CDCl3) δ 7.26 (d, 2H, J=8.5 Hz), 6.88 (d, 2H, J=8.5 Hz), 4.10 (m, 2H), 4.00 (s, 2H), 3.80 (s, 3H), 3.08 (m, 1H), 2.97-2.90 (m, 2H), 2.04 (m, 2H), 1.87-1.73 (m, 2H), 1.47 (s, 9H). ES-LCMS m/z 395.99 (M+Na).

Provenance & Evidence