Arkivoc 2018, vii, 0-0
Kavitha, K. et al.
3-(7-Fluoroquinoxalin-2-yl)-2H-chromen-2-one (4e). Brown color solid. Yield: 2.25 g (77%); mp: 167-169 °C
(Methanol); IR(KBr) νmax/ cm-1: 1725 cm-1 (strong, sharp, -CO of coumarin ring), 1H NMR (400 MHz, DMSO-d6/
TMS): δ 7.44-8.06 (complex, m, 7H, Ar-H), 8.90 (s, 1H, Ar-H), 9.55 (s, 1H, Ar-H); 13C NMR (100 MHz, DMSO-d6):
127.7, 128.3, 128.5, 129.6, 132.7, 132.8, 133.1, 139.7, 140.9, 141.2, 141.4, 144.1, 144.3, 145.1, 147.5, 153.7,
159.5; HRMS calculated for C17H9FN2O2 [M+H]+: 293.07263, Found: 293.07219.
3-(7-Chloroquinoxalin-2-yl)-2H-chromen-2-one (4f). Brown color solid. Yield: 2.50 g (81%); mp: 185-187 °C
1
(Acetone); IR(KBr) νmax/ cm-1: 1718 cm-1 (strong, sharp, -CO of coumarin ring); H NMR (400 MHz, DMSO-d6/
TMS): δ 7.43-8.07 (complex, m, 7H, Ar-H), 8.89 (s, 1H, Ar-H), 9.56 (s, 1H, Ar-H); 13C NMR (100 MHz, DMSO-d6):
126.9, 127.7, 128.2, 128.9, 131.9, 132.2, 132.9, 138.2, 140.5, 141.2, 141.8, 143.9, 144.1, 144.9, 146.9, 152.6,
158.8; HRMS calculated for C17H9ClN2O2 [M+H]+: 309.04308, Found: 309.04299.
6-Nitro-3-(quinoxalin-2-yl)-2H-chromen-2-one (4g). Yellow color solid. Yield: 2.48 g (78%); mp: 247-249 °C
1
(Ethanol); IR (KBr) vmax/cm-1: 1712 cm-1 (strong, sharp, -CO of coumarin ring); H-NMR (400 MHz, DMSO-d6/
13
TMS): δ 7.67-8.39 (complex, multiplet, 7H, Ar- H), 8.88 (s, 1H, Ar-H), 9.60 (s, 1H, Ar-H ); C-NMR (100 MHz,
DMSO-d6): 118.4, 123.4, 124.5, 124.5, 128.8, 129.0, 129.5, 129.7, 129.7, 142.2, 143.2, 144.3, 144.4, 146.7,
153.8, 159.5, 161.7; HRMS calculated for C17H9N3O4 [M+H]+: 320.06713, Found: 320.06245.
3-(7-Methylquinoxalin-2-yl)-6-nitro-2H-chromen-2-one (4h): Yellow color solid. Yield: 2.66 g (80%); mp: 202-
1
204 °C (Methanol); IR(KBr) νmax/ cm-1: 1734 cm-1 (strong, sharp, -CO of coumarin ring); H NMR (400 MHz,
DMSO-d6/ TMS): δ 2.43 (s, 3H, CH3), 7.58-8.52 (complex, m, 6H, Ar-H), 8.83 (s, 1H, Ar-H), 9.54 (s, 1H, Ar-H); 13C
NMR (100 MHz, DMSO-d6): 21.3, 118.0, 123.0, 124.6, 124.9, 127.3, 128.5, 129.6, 134.1, 138.7, 139.9, 141.4,
142.1, 144.3, 146.1, 153.4, 159.7, 161.5; HRMS calculated for C18H11N3O4 [M+H]+: 334.08278, Found:
334.08098.
3-(7-Methoxyquinoxalin-2-yl)-6-nitro-2H-chromen-2-one (4i). Yellow color solid. Yield: 2.75 g (79%); mp: 192-
1
194 °C (Methanol); IR(KBr) νmax/ cm-1: 1724 cm-1 (strong, sharp, -CO of coumarin ring); H NMR (400 MHz,
DMSO-d6/ TMS): δ 3.86 (s, 3H, OCH3), 7.53-8.56 (complex, m, 6H, Ar-H), 8.87 (s, 1H, Ar-H), 9.52 (s, 1H, Ar-H);
13C NMR (100 MHz, DMSO-d6): 55.3, 103.5, 118.6, 123.3, 124.5, 124.6, 127.7, 129.8, 130.7, 137.8, 140.1, 144.4,
144.7, 146.8, 154.6, 158.4, 159.0, 161.3; HRMS calculated for C18H11N3O5 [M+H]+: 350.07769, Found:
350.07812.
6-Nitro-3-(7-nitroquinoxalin-2-yl)-2H-chromen-2-one (4j). Yellow color solid. Yield: 2.98 g (82%); mp: 258-260
1
°C (Acetone); IR(KBr) νmax/ cm-1: 1712 cm-1 (strong, sharp, -CO of coumarin ring); H NMR (400 MHz, DMSO-
d6/ TMS): δ 7.64-8.56 (complex, m, 6H, Ar-H), 8.91 (s, 1H, Ar-H), 9.55 (s, 1H, Ar-H); 13C NMR (100 MHz, DMSO-
d6): 127.6, 128.3, 128.5, 129.6, 130.7, 132.7, 132.8, 133.1, 134.4, 139.7, 141.4, 144.3, 145.1, 147.0, 147.4,
153.7, 159.5; HRMS calculated for C17H8N4O6 [M+H]+: 365.05221, Found: 365.05011.
3-(7-Fluoroquinoxalin-2-yl)-6-nitro-2H-chromen-2-one (4k). Yellow color solid. Yield: 2.59 g (77%); mp: 231-
1
233 °C (Methanol); IR(KBr) νmax/ cm-1: 1708 cm-1 (strong, sharp, -CO of coumarin ring), H NMR (400 MHz,
DMSO-d6/ TMS): δ 7.44-8.56 (complex, m, 6H, Ar-H), 8.90 (s, 1H, Ar-H), 9.55 (s, 1H, Ar-H); 13C NMR (100 MHz,
DMSO-d6): 127.7, 128.3, 128.5, 129.6, 132.7, 132.8, 133.1, 139.7, 140.9, 141.2, 141.4, 144.1, 144.3, 145.1,
147.5, 153.7, 159.5; HRMS calculated for C17H8FN3O4 [M+H]+: 338.05771, Found: 338.05842.
3-(7-Chloroquinoxalin-2-yl)-6-nitro-2H-chromen-2-one (4l). Yellow color solid. Yield: 2.78 g (79%); mp: 215-
1
217 °C (Ethanol); IR(KBr) νmax/ cm-1: 1714 cm-1 (strong, sharp, -CO of coumarin ring); H NMR (400 MHz,
DMSO-d6/ TMS): δ 7.41-8.56 (complex, m, 6H, Ar-H), 8.85 (s, 1H, Ar-H), 9.56 (s, 1H, Ar-H); 13C NMR (100 MHz,
DMSO-d6): 68.3, 111.4, 115.8, 120.0, 125.9, 127.7, 129.2, 130.9, 131.9, 139.2, 139.9, 140.2, 142.5, 143.2,
143.8, 154.9, 163.7; HRMS calculated for C17H8ClN3O4 [M+H]+: 354.02816, Found: 354.02924.
General procedure for the one-pot three component synthesis of 4 from 1 & 3. A mixture of 1 (10 mmol),
TBATB (10 mmol), 3 (10 mmol) and PEG-600 (20 mL) was heated to 100 °C and maintained at the same
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