123.51, 127.89, 128.71, 131.31, 132.17, 132.78, 139.85, 144.54,
154.99. HRMS calcd for C18H13N3O3 319.0957; found: 319.0949.
(100 MHz, CDCl3) d 21.34, 24.11, 112.59, 112.95, 116.29, 122.30,
123.96, 124.34, 124.85, 126.08, 127.31, 129.09, 130.85, 132.98,
134.63, 138.79, 155.48. HRMS calcd for C18H14N2O 288.1263;
found: 288.1258.
4-Oxo-5-(p-tolyl)-4,5-dihydropyrrolo[1,2-a]quinoxaline-9-car-
bonitrile (5b). White solid (75%). mp 280–284 ◦C. 1H NMR (400
MHz, CDCl3) d 8.88 (dd, J = 3.08, 1.36 Hz, 1H), 7.51 (dd, J = 7.68,
1.36 Hz, 1H), 7.38–7.41 (m, 3H), 7.12–7.17 (m, 3H), 6.95 (dd, J =
8.48, 1.24 Hz, 1H), 6.80 (t, J = 3.16 Hz, 1H), 2.47 (s, 3H); 13C NMR
(100 MHz, CDCl3) d 21.32, 99.75, 114.47, 114.81, 118.58, 120.18,
122.31, 124.39, 124.65, 124.88, 128.94, 129.38, 131.15, 133.26,
133.45, 139.53, 154.77. HRMS calcd for C19H13N3O 299.1059;
found: 299.1062.
N-(4-Oxo-5-(p-tolyl)-4,5-dihydropyrrolo[1,2-a]quinoxalin-7-yl)-
◦
1
acetamide (5h). Yellow solid (77%). mp 291–294 C. H NMR
(300 MHz, DMSO-d6) d 9.96 (s, 1H), 8.18 (dd, J = 1.5 Hz, 1H),
8.07 (d, J = 9.0 Hz, 1H), 7.62 (dd, J = 9.0, 2.1 Hz, 1H), 7.42 (d,
J = 8.1 Hz, 2H), 7.24 (d, J = 8.1 Hz, 2H), 7.05 (dd, J = 3.9, 1.5
Hz, 1H), 6.84 (d, J = 2.1 Hz, 1H), 6.71 (dd, J = 3.9, 3.0 Hz, 1H),
2.44 (s, 3H), 1.94 (s, 3H); 13C NMR (100 Hz, DMSO-d6) d 21.35,
24.35, 107.55, 112.53, 113.39, 114.21, 115.93, 118.27, 119.18,
122.83, 129.76, 130.95, 131.92, 134.57, 137.41, 138.57, 155.09,
168.76. HRMS calcd for C20H17N3O2 331.1321; found: 331.1312.
4-Oxo-5-(p-tolyl)-4,5-dihydropyrrolo[1,2-a]quinoxaline-7-car-
bonitrile (5c). White solid (70%). mp 267–270 ◦C. 1H NMR (300
MHz, CDCl3) d 7.77 (d, J = 8.4 Hz, 1H), 7.73 (dd, J = 3.0, 1.5 Hz,
1H), 7.48 (dd, J = 8.4, 1.5 Hz, 1H), 7.42 (d, J = 7.8 Hz, 2H), 7.33
(dd, J = 3.9, 1.2 Hz, 1H), 7.17 (d, J = 8.1 Hz, 2 H), 6.96 (d, J =
1.5 Hz, 1H), 6.78 (dd, J = 3.6, 3.0 Hz, 1H), 2.45 (s, 3H); 13C NMR
(100 MHz, CDCl3) d 21.33, 108.64, 114.82, 114.84, 115.21, 117.09,
118.15, 121.23, 123.63, 126.51, 126.67, 128.81, 131.29, 132.37,
132.94, 139.81, 154.92. HRMS calcd for C19H13N3O 299.1059;
found: 299.1056.
5-(p-Tolyl)-7-(trifluoromethyl)pyrrolo[1,2-a]quinoxalin-4(5H)-
◦
1
one (5i). Brown solid (86%). mp 250–253 C. H NMR (400
MHz, CDCl3) d 7.78 (d, J = 8.48 Hz, 1H), 7.74 (dd, J = 2.80,
1.44 Hz, 1H), 7.43–7.46 (m, 1H), 7.40 (d, J = 8.00 Hz, 2H), 7.31
(dd, J = 3.84, 1.36 Hz, 1H), 7.18 (d, J = 8.20 Hz, 2H), 6.93 (m,
1H), 6.75 (dd, J = 3.72, 2.96 Hz, 1H), 2.47 (s, 3H); 13C NMR
(100 MHz, CDCl3) d 21.36, 109.63, 113.54, 114.32 (d, J = 4.0
Hz), 114.74, 114.89, 116.97, 119.85 (q, J = 3.1 Hz), 120.13 (d, J =
34.7 Hz), 122.02, 123.94, 128.84, 129.49, 131.91, 133.13, 139.51,
155.29. HRMS calcd for C19H13F3N2O 342.0980; found: 342.0972.
5-(p-Tolyl)-3-(trifluoromethyl)pyrido[3,2-e]pyrrolo[1,2-a]pyra-
zin-6(5H)-one (5d). White solid (97%). mp 187–190 ◦C. 1H NMR
(400 MHz, CDCl3) d 8.45 (d, J = 0.68 Hz, 1H), 8.19 (dd, J = 2.84,
1.60 Hz, 1H), 7.42 (d, J = 8.08 Hz, 2H), 7.36 (dd, J = 3.72, 1.48
Hz, 1H), 7.19 (d, J = 8.20 Hz, 2H), 7.14 (d, J = 1.64 Hz, 1H), 6.76
(t, J = 3.28 Hz, 1H), 2.49 (s, 3H); 13C NMR (100 MHz, CDCl3)
d 21.37, 114.64, 115.87, 118.59, 121.03 (d, J = 3.0 Hz), 123.53
(q, J = 22.3 Hz), 123.97, 124.51, 127.45, 128.68, 131.30, 132.32,
137.74, 138.60 (d, J = 4.1 Hz), 139.90, 154.69. HRMS calcd for
C18H12F3N3O 343.0932; found: 343.0932.
5-(p-Tolyl)pyrido[3,2-e]pyrrolo[1,2-a]pyrazin-6(5H)-one
(5j).
White solid (68%). mp 239–242 ◦C. 1H NMR (300 MHz, CDCl3)
d 8.17–8.21 (m, 2H), 7.39 (d, J = 8.1 Hz, 2H), 7.32 (dd, J =
3.9, 1.5 Hz, 1H), 7.20 (d, J = 8.1 Hz, 2H), 7.07 (dd, J = 8.4, 4.8
Hz, 1H), 6.98 (dd, J = 8.1, 1.5 Hz, 1H), 6.73 (dd, J = 3.6, 3.0
Hz, 1H), 2.47 (s, 3H); 13C NMR (100 MHz, CDCl3) d 21.32,
113.69, 114.71, 117.86, 120.71, 123.41, 124.34, 127.46, 128.93,
130.95, 133.11, 135.75, 139.28, 141.66,155.04. HRMS calcd for
C17H13N3O 275.1059; found: 275.1062.
7-Fluoro-5-(p-tolyl)pyrrolo[1,2-a]quinoxalin-4(5H)-one
(5e).
Orange solid (82%). mp 219–222 ◦C. 1H NMR (300 MHz, CDCl3)
d 7.64–7.68 (m, 2H), 7.39 (d, J = 8.1 Hz, 1H), 7.27 (dd, J = 3.9,
1.5 Hz, 1H), 7.19 (dd, J = 4.2, 2.4 Hz, 1H), 6.88–6.94 (m, 1H),
6.70 (dd, J = 3.9, 3.0 Hz, 1H), 6.40 (dd, J = 10.5, 2.7 Hz, 1H),
2.47 (s, 3H); 13C NMR (100 MHz, CDCl3) d 21.33, 104.82 (d, J =
29.2 Hz), 109.78 (d, J = 24.1 Hz), 113.46, 115.52 (d, J = 9.1 Hz),
116.43, 120.26, 123.02, 128.90, 130.98, 133.28, 133.63, 139.28,
155.45, 158.60, 161.02. HRMS calcd for C18H13FN2O 292.1012;
found: 292.1030.
5,7-Di-p-tolylpyrrolo[1,2-a]pyrrolo[1¢,2¢:4,5]pyrazino[2,3-g]-qui-
noxaline-4,8(5H,7H)-dione (5k). Orange solid (60%). mp 273–
◦
1
278 C. H NMR (400 MHz, DMSO-d6) d 8.82 (s, 1H), 8.45 (d,
J = 1.08 Hz, 2H), 7.19 (d, J = 8.04 Hz, 4H), 7.10 (dd, J = 3.8,
1.2 Hz, 2H), 7.00 (d, J = 8.12 Hz, 4H), 6.80 (t, J = 3.04 Hz,
2H), 5.57 (s, 1H), 2.36 (s, 6H); 13C NMR (100 MHz, DMSO-d6)
d 21.15, 102.20, 105.88, 113.23, 113.73, 119.29, 119.43, 123.12,
129.24, 129.36, 130.42, 133.96, 138.51, 154.53. HRMS calcd for
C30H22N4O2 470.1743, found: 470.1736.
8-Methyl-5-(p-tolyl)pyrrolo[1,2-a]quinoxalin-4(5H)-one
(5f).
Orange solid (85%). mp 201–203 ◦C. 1H NMR (400 MHz, CDCl3)
d 7.69 (dd, J = 2.64, 1.48 Hz, 1H), 7.51 (s, 1H), 7.37 (d, J = 8.04
Hz, 2H), 7.27 (d, J = 1.40 Hz, 1H), 7.19 (d, J = 8.20 Hz, 2H),
6.90 (dd, J = 8.48, 1.04 Hz, 1H), 6.69 (dd, J = 3.72, 2.96 Hz, 1H),
6.57 (d, J = 8.44 Hz, 1H), 2.46 (s, 3H), 2.42 (s, 3H); 13CNMR
(100 MHz, CDCl3) d 20.93, 21.32, 113.10, 113.23, 114.66, 116.15,
117.50, 123.51, 123.64, 125.95, 129.10, 129.47, 130.72, 132.93,
134.15, 138.76, 155.47. HRMS calcd for C18H14N2O 288.1263;
found: 288.1271.
5-(p-Tolyl)indolo[1,2-a]quinoxalin-6(5H)-one
(11a). Yellow
solid (92%). mp 208–209 ◦C. 1H NMR (400 MHz, CDCl3) d
8.38 (dd, J = 8.32 Hz, 1.04 Hz, 1H), 8.32 (d, J = 8.72 Hz, 1H),
7.90 (d, J = 7.96 Hz, 1H), 7.65 (d, J = 0.44 Hz, 1H), 7.51–7.56
(m, 1H), 7.36–7.42 (m, 3H), 7.27–7.31 (m, 1H), 7.23–7.25 (m,
2H), 7.06–7.11 (m, 1H), 6.75 (dd, J = 8.32, 1.32 Hz, 1H),
2.48 (s, 3H);13C NMR (100 MHz, CDCl3) d 21.33, 107.47,
114.32, 115.38, 117.73, 122.47, 123.33, 123.78, 125.48, 126.50,
128.42, 128.96, 129.36, 130.87, 131.28, 133.96, 134.47, 139.05,
156.55. HRMS calcd for C22H16N2O 324.1263; found: 324.
1282.
9-Methyl-5-(p-tolyl)pyrrolo[1,2-a]quinoxalin-4(5H)-one
(5g).
Orange solid (95%). mp 247–249 ◦C. 1H NMR (300 MHz, CDCl3)
d 8.08 (dd, J = 2.7, 1.5 Hz, 1H), 7.34–7.39 (m, 3H), 7.18 (d, J =
8.1 Hz, 2H), 6.94–7.03 (m, 2H), 6.69 (dd, J = 3.9, 3.0 Hz, 1H),
6.58 (dd, J = 7.8, 1.5 Hz, 1H), 2.87 (s, 3H), 2.46 (s, 3H); 13C NMR
9-Methoxy-5-(p-tolyl)indolo[1,2-a]quinoxalin-6(5H)-one (11b).
White solid (82%). mp 255–256 ◦C. 1H NMR (300 MHz, CDCl3)
d 8.32 (dd, J = 8.4 Hz, 1H), 8.22 (d, J = 9.3 Hz, 1H), 7.57 (s, 1H),
7356 | Org. Biomol. Chem., 2011, 9, 7351–7357
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The Royal Society of Chemistry 2011
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