Hydrochloric Acid → 9-Bromo-5-(o-ethoxycarbonylphenylcarbamoylmethyl)-6,7-dihydro-1H, 5H-pyrido[1,2,3-de]quinoxaline-2,3-dione

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Reaction Steps

To a solution of 9-bromo-5-carboxymethyl-6,7-dihydro-1H, 5H-pyrido[1,2,3-de]quinoxaline-2,3-dione (340 mg, 1 mmol), o-ethoxycarbonylaniline (150 μL, 1 mmol), and triethylamine (280 μL, 2 mmol) in dichloromethane (3 mL) was added N,N-bis(2-oxo-3-oxazolydinyl)phosphinic chloride (254 mg, 1 mmol) at 0° C. The mixture was stirred overnight at room temperature and 0.2N hydrochloric acid was added. The organic layer was separated and the aqueous layer was extracted with dichloromethane. The combined organic layers were washed with brine, dried over magnesium sulfate, and concentrated. The residual solid was rinsed with diethyl ether and dried in vacuo to give 290 mg of the title compound (58%): mp>265°~267° C.; 1H NMR (270 MHz, DMSO-d6) δ12.05 (bs, 1H), 10.55 (s, 1H), 8.14 (d, 1H, J=8.1 Hz), 7.89 (d, 2H, J=8.1 Hz), 7.60 (t, 1H, J=8.1 Hz), 7.23 (d, 1H, J=2 Hz), 7.22 (t, 1H, J=8.1 Hz), 7.16 (d, 1H, J=2 Hz), 5.14~5.26 (m, 1H), 4.29 (q, 2H, J=7.2 Hz), 3.06 (ddd, 1H, J=17.1, 13.5, 4.5 Hz), 2.82 (dm, 1H, J=17.1 Hz), 2.62~2.76 (m, 2H), 2.18 (dm, 1H, J=13.5 Hz), 1.81~1.97 (m, 1H), 1.32 (t, 3H, J=7.2 Hz).

Provenance & Evidence