Ethanol → Methyl 4-bromo-12-oxo-5,6,7,8,9,10,11,12-octahydrocycloocta[b]quinoline-1-carboxylate

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

A mixture of methyl 2-oxocyclooctanecarboxylate (32.0 g, 174 mmol), methyl 3-amino-4-bromobenzoate (20.0 g, 87 mmol) and ethanol (120 mL) was heated to reflux, at an oil bath of 130° C., acetic acid (1.5 mL) was added and the mixture was reflux for 1.5 hours. Hot PPA (200 g, 120° C.) was added to the reaction mixture carefully. The reaction mixture was heated at an oil bath of 130° C. for 3 hours. After cooling for a while, ice (200 g), ethyl acetate (60 mL) and petroleum ether (60 mL) were added to the reaction mixture, the mixture was concentrated until 200 mL solvent was removed. Then water (600 mL) and ethyl acetate (60 mL) were added, the resulting mixture was stayed at room temperature overnight. A light brown solid was slowly formed. The mixture was filtered and the filtered cake was dried to give a light brown solid, which was placed into methanol (90 mL). SOCl2 (30 mL) was added dropwise with cooling with an ice-bath. The resulting mixture was heated to reflux for 4 hours, concentrated and treated with saturated NaHCO3 solution (60 mL) and ethyl acetate (30 mL), filtered and the filtered cake was dried to give desired product (6.6 g) as a pale white solid (21%). 1H NMR (DMSO-d6) δ10.25 (s, 1H), 7.96-7.98 (d, 1H, J=7.6 Hz), 7.09-7.11 (d, 1H, J=7.6 Hz), 3.02-3.06 (m, 2H), 2.63-2.66 (m, 2H), 1.75-1.77 (m, 2H), 1.53-1.55 (m, 2H), and 1.36-1.39 (m, 4H). MS (ESI) m/e [M+1]+ 364/366.

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