Aniline → 1-[[(o-Tolylamino)carbonyl]amino]-1,4-dihydro-2,3-quinoxalinedione

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

To a stirred solution of N-carboxymethyl-6,7-dibromo-1,4-dihydroquinoxaline-2,3-dione (100 mg, 0.250 mmol) and aniline (25 mg, 0.25 mmol) in dry DMF (1.5 mL) under N2 at 28° C., DCC (55 mg, 0.25 mmol) was added in one portion. The solution was stirred at 28° C. for 18 h. The insoluble white solid was filtered and the clear filtrate was poured into water (6 mL). The precipitated solid was filtered and air dried to obtain 113 mg crude product as a grey powder. The crude product was then purified by Soxhlet extraction in boiling ethanol (20 mL), keeping the oil bath temperature at 120° C., for 5 h. The residue (in the thimble) was dried in the oven (approx. 70°-80° C.) overnight to furnish 35 mg pure (1H NMR) N-(N'-phenylcarboxamidyl)methyl-6,7-dibromo-1,4-dihydroquinox-aline-2,3-dione as a light grey powder; m.p. >300° C. (decomposes). 1H NMR: δ 4.97 (s, 1H), 6.99-7.11 (m, 1H), 7.23-7.37 (m, 2H), 7.44 (s, 1H), 7.52 (d, 2H, J=8.4 Hz), 7.73 (s, 1H), 10.25 (s, 1H), 12.25 (s, 1H). IR (KBr, cm-1): 3620, 3468, 1714, 1694, 1595, 1542. HRMS: Calculated for C16H11Br2N3O3, 450.9168; Observed, 450.9177.

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