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chromatographed on silica gel (100–200 mesh) using 2 : 8 ethyl 128.2, 128.1, 123.9, 113.4, 48.6. HRMS (ESI): calculated m/z for
acetate–hexane as the eluent to get the pure 3-aryl quinoxalin-
2(1H)-ones 3. Products 3aa, 3ba, 3da, 3ea, 3ia, 3ma, 3mc, 3me,
C
22H16N2O2 [M + H]+: 341.1292, found: 341.1285.
1-(2-(2-Bromophenyl)-2-oxoethyl)-3-phenylquinoxalin-2(1H)-one
3nd, 3oa, 3pa, 3ab, 3ac, 3ad & 3ae are known in the literature5,6 (3ka). Yellow solid, mp 168.6–172.5 C, 65% yield. IR (CHCl3):
ꢀ
and the spectral data of unknown compounds 3ca, 3fa, 3ga, 3ha, 3059.5, 2949.1, 1960.7, 1711.9, 1648.6, 1440.2, 1217.1, 986.5,
1
3ja, 3ka, 3la, 3mb, 3md, 3mf, 3oc, 3pb, 5 & 7 have been given 763.6, 430.9 cmꢁ1. H NMR (CDCl3, 500 MHz): d 8.31–8.29 (m,
here.
2H), 7.99 (dd, 1H, J ¼ 8.0, 1.5 Hz), 7.72–7.67 (m, 2H), 7.56–7.52
1-Butyl-3-phenylquinoxalin-2(1H)-one (3ca). Orange liquid, (m, 1H), 7.49–7.44 (m, 4H), 7.41–7.37 (m, 2H), 7.23 (dd, 1H, J ¼
73% yield. IR (CHCl3): 3057.5, 2959.1, 1652.0, 1603.5, 1465.3, 8.5, 1.0 Hz), 5.67 (s, 2H). 13C NMR (CDCl3, 125 MHz): d 195.1,
1295.3, 1180.7, 763.5, 692.2, 426.7 cmꢁ1. H NMR (CDCl3, 500 154.2, 153.7, 138.6, 135.6, 133.8, 133.2, 132.68, 132.62, 130.6,
1
MHz): d 8.30 (dd, 2H, J ¼ 7.0, 3.5 Hz), 7.95 (dd, 1H, J ¼ 8.0, 1.5 130.4, 130.3, 129.4, 128.0, 127.7, 123.9, 118.9, 113.4, 51.2. HRMS
Hz), 7.56 (t, 1H, J ¼ 8.5 Hz), 7.47–7.46 (m, 3H), 7.36–7.32 (m, (ESI): calculated m/z for C22H15BrN2O2 [M + H]+: 419.0390,
2H), 4.32 (t, 2H, J ¼ 8.0 Hz), 1.81 (p, 2H, J ¼ 7.5 Hz), 1.55 (sextet, found: 419.0392.
2H, J ¼ 7.5 Hz), 1.02 (t, 3H, J ¼ 7.5 Hz). 13C NMR (CDCl3, 125
1-(2-(Naphthalen-2-yl)-2-oxoethyl)-3-phenylquinoxalin-2(1H)-
MHz): d 154.3, 154.0, 135.9, 133.2, 132.4, 130.5, 130.16, 130.12, one (3la). Brown solid, mp 207.0–219.4 ꢀC, 56% yield. IR (KBr):
129.4, 127.9, 123.4, 113.4, 42.3, 29.2, 20.2, 13.7. HRMS (ESI): 3245.5, 2938.3, 2220.9, 1650.5, 1601.5, 1464.1, 1241.0, 1176.6,
calculated m/z for C18H18N2O [M + H]+: 279.1492, found: 750.5, 693.7, 534.2 cmꢁ1.1H NMR (CDCl3, 500 MHz): d 8.67 (s,
279.1493.
1-(3-Methylbut-2-enyl)-3-phenylquinoxalin-2(1H)-one
1H), 8.33 (dd, 2H, J ¼ 6.0, 2.5 Hz), 8.10 (dd, 1H, J ¼ 9.0, 2.0 Hz),
(3fa). 8.03–7.98 (m, 3H), 7.93 (d, 1H, J ¼ 8.0 Hz), 7.68–7.59 (m,
Orange solid, mp 97.9–115.2 ꢀC, 61% yield. IR (CHCl3): 3295.8, 2H),7.49–7.45 (m, 4H), 7.38 (t, 1H, J ¼ 7.5 Hz), 7.05 (dd, 1H, J ¼
2916.7, 1652.0, 1604.4, 1466.3, 1293.8, 1178.5, 762.3, 692.1, 8.5,1.0 Hz), 5.94 (s, 2H). 13C NMR (CDCl3, 125 MHz): d 191.1,
425.2 cmꢁ1 1H NMR (CDCl3, 500 MHz): d 8.31–8.29 (m, 2H), 154.4, 153.7, 135.9, 135.7, 133.2, 132.7, 132.3, 131.8, 130.6,
.
7.95 (dd, 1H, J ¼ 7.5, 1.0 Hz), 7.55–7.52 (m, 1H), 7.48–7.45 (m, 130.3, 130.0, 129.6, 129.4, 129.3, 129.0, 128.9, 127.9, 127.8,
3H), 7.36–7.29 (m, 2H), 5.23–5.20 (m, 1H), 4.96 (d, 2H, J ¼ 6.5 127.1, 123.8, 123.3, 123.0, 113.7, 113.4, 48.6. HRMS (ESI):
Hz), 1.92 (s, 3H), 1.74 (s, 3H). 13C NMR (CDCl3, 125 MHz): calculated m/z for C26H18N2O2 [M + H]+: 391.1441, found:
d 154.2, 154.1, 137.2, 136.0, 133.2, 132.5, 130.4, 130.1, 130.0, 391.1450.
129.4, 127.9, 123.4, 117.8, 113.8, 40.8, 25.5, 18.3.
1-(But-3-enyl)-3-phenylquinoxalin-2(1H)-one (3ga). Yellow mp 233.6–237.7 ꢀC, 70% yield. IR (KBr): 3421.8, 2926.4, 1667.3,
liquid, 61% yield. IR (CHCl3): 3075.0, 2976.6, 1651.9, 1602.8, 1610.8, 1417.9, 1116.5, 902.2, 754.6, 618.5 cmꢁ1 1H NMR
3-(3-Chlorophenyl) quinoxalin-2(1H)-one (3mb). Brown solid,
.
1465.3, 1295.7, 919.1, 762.9, 692.1, 428.4 cmꢁ1. 1H NMR (CDCl3, (DMSO-d6, 500 MHz) d 12.67 (s, 1H), 8.38 (s, 1H), 8.30 (dd, 1H, J
500 MHz): d 8.31–8.29 (m, 2H), 7.96 (dd, 1H, J ¼ 8.0, 1.5 Hz), ¼ 8.0, 1.5 Hz), 7.87 (d, 1H, J ¼ 7.5 Hz), 7.59–7.52 (m, 3H), 7.36 (d,
7.57–7.54 (m, 1H), 7.49–7.46 (m, 3H), 7.37–7.32 (m, 2H), 5.96– 2H, J ¼ 7.0 Hz). 13C NMR (DMSO-d6, 125 MHz): d 154.8, 152.7,
5.87 (m, 1H), 5.17–5.09 (m, 2H), 4.40 (t, 2H, J ¼ 8.0 Hz), 2.58 (q, 137.8, 132.9, 132.5, 132.2, 131.1, 130.28, 130.21, 129.2, 129.1,
2H, J ¼ 7.0 Hz). 13C NMR (CDCl3, 125 MHz): d 154.2, 154.0, 128.0, 123.8, 115.5. HRMS (ESI): calculated m/z for C14H9ClN2O
135.9, 133.8, 133.2, 132.3, 130.6, 130.2, 130.1, 129.4, 127.9, [M + H]+: 257.0476, found: 257.0486.
123.5, 117.6, 113.4, 41.7, 31.4. HRMS (ESI): calculated m/z for
18H16N2O [M + H]+: 277.1335, found: 277.1346.
3-(3-Fluorophenyl) quinoxalin-2(1H)-one (3md). Brownish
yellow solid, mp 225.6–227.5 ꢀC, 76% yield. IR (KBr): 3433.8,
C
3-Phenyl-1-(prop-2-ynyl) quinoxalin-2(1H)-one (3ha). Yellow 3068.5, 2848.7, 1668.5, 1607.8, 1475.1, 1246.5, 896.9, 783.0,
solid, mp 139.9–143.2 ꢀC, 60% yield. IR (CHCl3): 3282.6, 1651.3, 555.4 cmꢁ1.1H NMR (DMSO-d6, 500 MHz) d 12.66 (s, 1H), 8.20–
1603.4, 1464.3, 1173.9, 1029.8, 753.8, 427.0 cmꢁ1
.
1H NMR 8.31 (m, 2H), 7.86 (dd, 1H, J ¼ 8.0, 2.5 Hz), 7.58–7.52 (m, 2H),
(CDCl3, 400 MHz): d 8.31 (dd, 2H, J ¼ 6.4, 2.0 Hz), 7.96 (dd, 1H, J 7.38–7.32 (q, 3H, J ¼ 6.5 Hz). 13C NMR (DMSO-d6, 125 MHz):
¼ 8.4, 1.6 Hz), 7.61–7.57 (m, 1H), 7.48–7.46 (m, 4H), 7.41–7.37 d 162.9 (d, J ¼ 240.625 Hz), 154.8, 152.7, 138.1 (d, J ¼ 8.125 Hz),
(m, 1H), 5.12 (d, 2H, J ¼ 2.8 Hz), 2.30 (t, 1H, J ¼ 2.4 Hz). 13C NMR 132.5, 132.1, 131.1, 130.2 (d, J ¼ 8.0 Hz), 129.2, 125.5 (d, J ¼
(CDCl3, 100 MHz): d 154.1, 153.8, 135.8, 133.9, 131.9, 130.7, 2.625 Hz), 123.8, 117.4 (d, J ¼ 21.0 Hz), 116.1(d, J ¼ 23.375 Hz),
130.6, 130.5, 129.6, 128.2, 124.2, 114.1, 76.9, 73.2, 31.7. HRMS 115.5. HRMS (ESI): calculated m/z for C14H9FN2O [M + H]+:
(ESI): calculated m/z for C17H12N2O [M + H]+: 261.1022, found: 241.0772, found: 241.0775.
261.1032.
1-(2-Oxo-2-phenylethyl)-3-phenylquinoxalin-2(1H)-one
3-(4-(Triuoromethyl) phenyl) quinoxalin-2(1H)-one (3mf).
(3ja). Brown solid, mp 291.7–294.7 ꢀC, 59% yield. IR (KBr): 3434.6,
Brownish yellow solid, mp 198.1–201.3 ꢀC, 71% yield. IR 2850.5, 1663.3, 1610.8, 1330.1, 1114.8, 906.5, 760.1, 618.6 cmꢁ1
.
(CHCl3): 3058.5, 1691.3, 1648.6, 1446.9, 1227.4, 989.1, 754.6, 1H NMR (500 MHz, DMSO-d6) d 12.70 (s, 1H), 8.51 (d, 2H, J ¼ 8.5
423.5 cmꢁ1
.
1H NMR (CDCl3, 500 MHz): d 8.33–8.30 (m, 2H), Hz), 7.86 (d, 3H, J ¼ 8.5 Hz), 7.59 (t, 1H, J ¼ 8.0 Hz), 7.36–7.33
8.10 (dd, 2H, J ¼ 8.0, 0.5 Hz), 7.99 (dd, 1H, J ¼ 8.0, 1.0 Hz), 7.69 (m, 2H). 13C NMR (DMSO-d6, 125 MHz): d 154.8, 153.1, 139.6,
(tt, 1H, J ¼ 7.5, 2.0 Hz), 7.57 (t, 2H, J ¼ 8.0 Hz), 7.49–7.44 (m, 132.6, 132.2, 131.3, 130.2, 129.3, 125.1, 125.0, 123.9, 115.5.
4H), 7.37–7.33 (m, 1H), 6.99 (dd, 1H, J ¼ 8.5, 1.0 Hz), 5.79 (s, HRMS (ESI): calculated m/z for C15H9F3N2O [M + H]+: 291.0740,
2H). 13C NMR (CDCl3, 125 MHz): d 191.2, 154.4, 153.8, 135.8, found: 291.0750.
134.6, 134.3, 133.3, 132.8, 130.7, 130.43, 130.4, 129.6, 129.0,
6,7-Dichloro-1-methyl-3-p-tolylquinoxalin-2(1H)-one
(3oc).
Brown solid, mp 180.9–183.4 ꢀC, 61% yield. IR (CHCl3): 3394.4,
3622 | RSC Adv., 2020, 10, 3615–3624
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