O-Phenylenediamine → 3-(2-Thienyl)-1,2-dihydroquinoxalin-2-one

Beteiligte Stoffe

Reaktionsschritte

A mixture of o-phenylenediamine (2.16 g, 20 mmol) and ethyl thiophene-2-glyoxylate (3.68 g, 20 mmol.) in anhydrous methanol (60 mL) was stirred at room temperature for 12 hours under nitrogen atmosphere. The precipitate formed during this time was collected and washed with methanol to give a crude yellow solid, which was recrystallized from ethanol to give pure 3(2-thienyl)quinoxalin-2(1 H)-one (3.2 g, 70%). 1 H NMR (400 MHz, DMSO-d6) δ 12.7 (s, 1 H), 8.39 (d, J=4.4 Hz, 1 H), 7.83 (d, J=5.2 Hz, 1 H), 7.77 (d, J=8.0 Hz, 1H), 7.50 (t, J=7.6 Hz, 1H), 7.35˜7.29 (m, 1 H), 7.22 (t, J=4.8 Hz, 1 H).

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