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petroleum and ethyl acetate (v/v ¼ 3 : 1) as developing reagent ArH), 6.94 (d, J ¼ 7.2 Hz, 1H, ArH), 6.85 (t, J ¼ 8.4 Hz, 2H, ArH),
to give the pure product.
5.55 (s, 1H, CH), 3.79 (s, 3H, OCH3), 2.21 (s, 3H, CH3). Keto–enol
4-Ethyl 1-methyl 2-((2-(1H-indol-3-yl)ethylamino)methylene)- ¼ 3 : 1. 13C NMR (100 MHz, DMSO-d6) d: 128.3, 163.7, 143.5,
3-(5-uoro-2-oxoindolin-3-yl)succinate (3a). White solid, 60%, 137.6, 136.5, 135.1, 133.5, 132.7, 131.0, 130.2, 130.0, 129.4,
1
m.p. 70–71 ꢀC; H NMR (600 MHz, DMSO-d6) d: 10.83 (s, 1H, 129.3, 129.1, 127.7, 125.8, 123.1, 121.3, 118.1, 113.0, 109.2, 50.6,
NH), 10.39 (s, 1H, NH), 8.02 (brs, 1H, NH), 7.53 (d, J ¼ 7.2 Hz, 1H, 45.0, 20.9; IR (KBr) n: 3135, 3080, 3033, 2944, 2891, 2843, 1701,
ArH), 7.32 (d, J ¼ 8.4 Hz, 1H, ArH), 7.11 (s, 1H, ArH), 7.06 (d, J ¼ 1653, 1618, 1519, 1457, 1253, 1232, 1197, 1105, 1085, 879, 831,
8.4 Hz, 1H, ArH), 7.00–6.96 (m, 1H, ArH), 6.89 (d, J ¼ 13.2 Hz, 1H, 752 cmꢁ1; MS (m/z): HRMS (ESI) calcd for C27H21ClN2O3 ([M +
ArH), 6.74–6.73 (m, 1H, ArH), 4.11 (t, J ¼ 6.6 Hz, 2H, CH), 3.91– Na]+): 479.1140. Found: 479.1133.
3.80 (m, 2H, CH), 3.40–3.36 (m, 2H, CH), 3.31 (s, 3H, OCH3), 2.83
Methyl 4-(5-chloro-2-oxoindolin-3-yl)-5-(4-methoxyphenyl)-1-
(t, J ¼ 6.0 Hz, 2H, CH), 1.60 (t, J ¼ 6.6 Hz, 3H, CH3); 13C NMR (150 p-tolyl-1H-pyrrole-3-carboxylate (4b). White solid, 74%, m.p.
MHz, DMSO-d6) d: 177.2, 172.7, 168.0, 158.1, 156.5, 153.8, 139.2, 250–253 ꢀC; 1H NMR (400 MHz, DMSO-d6) d: keto-form: 10.50 (s,
136.2, 129.2, 129.1, 127.0, 122.8, 120.9, 118.3, 118.2, 114.0, 113.8, 1H, NH), 7.66 (s, 1H, CH), 7.21–7.15 (m, 7H, ArH), 6.97 (brs, 2H,
113.7, 113.6, 111.3, 110.9, 109.5, 109.4, 87.2, 60.3, 56.0, 49.6, ArH), 6.92 (d, J ¼ 8.4 Hz, 2H, ArH), 6.83 (d, J ¼ 8.4 Hz, 1H, ArH),
48.7, 48.6, 46.0, 27.1, 18.5, 14.0; IR (KBr) n: 3307, 2917, 2849, 4.36 (s, 1H, CH), 3.73 (s, 3H, OCH3), 3.41 (s, 3H, OCH3), 2.29 (s,
1715, 1668, 1607, 1484, 1445, 1381, 1308, 1227, 1193, 1183, 3H, CH3); enol-form: 10.18 (s, 1H, NH), 7.13 (brs, 1H, ArH), 7.80
1040, 932 cmꢁ1; MS (m/z): HRMS (ESI) calcd for C26H26FN3NaO5 (d, J ¼ 7.6 Hz, 2H, ArH), 7.01 (brs, 1H, ArH), 6.63 (d, J ¼ 8.4 Hz,
([M + Na]+): 502.1760. Found: 502.1749.
2H, ArH), 6.45 (d, J ¼ 8.0 Hz, 2H, ArH), 5.56 (s, 1H, CH), 3.81 (s,
4-Ethyl 1-methyl 2-((2-(1H-indol-3-yl)ethylamino)methylene)- 3H, OCH3), 3.64 (s, 3H, OCH3), 2.24 (s, 3H, CH3). Keto–enol ¼
3-(1-butyl-5-uoro-2-oxoindolin-3-yl)succinate (3b). White solid, 5 : 1. 13C NMR (100 MHz, CDCl3) d: 178.1, 163.8, 159.5, 142.5,
65%, m.p. 102–103 ꢀC; 1H NMR (600 MHz, DMSO-d6) d: 10.84 (s, 137.4, 136.8, 136.6, 133.4, 132.4, 130.0, 128.7, 127.5, 125.8,
1H, NH), 8.01–7.99 (m, 1H, NH), 7.52 (d, J ¼ 7.8 Hz, 1H, ArH), 125.3, 123.1, 122.5, 116.6, 114.4, 113.3, 110.5, 55.5, 50.6, 45.2,
7.32 (d, J ¼ 7.8 Hz, 1H, ArH), 7.11–7.05 (m, 4H, ArH), 6.97–6.93 20.9; IR (KBr) n: 3178, 3123, 3034, 2946, 2918, 2860, 1698, 1625,
(m, 2H, ArH), 6.83 (d, J ¼ 13.2 Hz, 1H, ArH), 4.15–4.10 (m, 2H, 1518, 1490, 1248, 1204, 1123, 1096, 1024, 836, 810 cmꢁ1; MS
CH), 3.97 (d, J ¼ 4.8 Hz, 1H, CH), 3.85 (d, J ¼ 5.4 Hz, 1H, CH), (m/z): HRMS (ESI) calcd for C28H23ClN2O4 ([M + Na]+): 509.1235.
3.68–3.63 (m, 1H, CH), 3.59–3.51 (m, 1H, CH), 3.39–3.34 (m, 2H, Found: 509.1239.
CH), 3.29 (s, 3H, OCH3), 2.82 (t, J ¼ 7.2 Hz, 2H, CH), 1.47 (t, J ¼
Methyl
4-(5-chloro-2-oxoindolin-3-yl)-1,5-bis(4-methoxy-
7.8 Hz, 3H, CH), 1.25–1.21 (m, 2H, CH), 1.16 (t, J ¼ 7.2 Hz, 3H, phenyl)-1H-pyrrole-3-carboxylate (4c). White solid, 80%, m.p.
CH3), 0.85 (t, J ¼ 7.8 Hz, 3H, CH); 13C NMR (150 MHz, DMSO-d6) 245–248 ꢀC; 1H NMR (400 MHz, DMSO-d6) d: keto-form: 10.49 (s,
d: 175.1, 172.6, 168.0, 158.4, 156.9, 153.8, 140.2, 136.3, 128.5, 1H, NH), 7.63 (s, 1H, CH), 7.21–7.18 (m, 5H, ArH), 6.97 (brs, 1H,
128.4, 127.0, 122.7, 121.0, 118.2, 114.0, 113.9, 113.8, 113.7, ArH), 6.93–6.91 (m, 4H, ArH), 6.88 (d, J ¼ 8.0 Hz, 1H, ArH), 4.34
111.3, 110.8, 108.7, 108.6, 86.9, 60.4, 48.5, 48.7, 48.1, 46.4, 29.0, (s, 1H, CH), 3.75 (s, 3H, OCH3), 3.72 (s, 3H, OCH3), 3.41 (s, 3H,
27.1, 19.3, 14.0, 13.4; IR (KBr) n: 3315, 2917, 2850, 1730, 1684, OCH3); enol-form: 10.17 (s, 1H, NH), 7.05 (d, J ¼ 8.4 Hz, 2H,
1665, 1616, 1486, 1465, 1382, 1207, 1227, 1198, 1152, 1102, ArH), 6.64 (d, J ¼ 8.4 Hz, 2H, ArH), 6.50 (m, 5H, ArH), 5.56 (s, 1H,
1039, 1001, 889 cmꢁ1; MS (m/z): HRMS (ESI) calcd for C30H34
-
CH), 3.81 (s, 3H, OCH3), 3.70 (s, 3H, OCH3), 3.63 (s, 3H, OCH3).
Keto–enol ¼ 5 : 1. 13C NMR (100 MHz, DMSO-d6) d: 178.1, 163.8,
159.5, 158.7, 142.5, 136.8, 133.5, 132.5, 132.2, 128.8, 127.5,
127.5, 127.4, 125.3, 123.1, 122.5, 116.4, 114.6, 114.4, 113.1,
110.5, 55.8, 55.5, 50.6, 45.3; IR (KBr) n: 3309, 3123, 3002, 2932,
2836, 1733, 1699, 1653, 1616, 1558, 1540, 1508, 1251, 1199,
FN3NaO5 ([M + Na]+): 558.2386. Found: 558.2375.
4. General procedure for the one-pot synthesis of
functionalized 2-pyrrolo-3-yloxindoles 4a–4f
A mixture of arylamine (1.0 mmol) and methyl propiolate 1177, 1094, 1027, 813 cmꢁ1; MS (m/z): HRMS (ESI) calcd for
(1.0 mmol) in 5.0 mL absolute ethanol was stirred at room C28H23ClN2O5 ([M + Na]+): 525.1184. Found: 525.1188.
temperature for 24 hours. Then, 3-phenacylideneoxindole
Methyl
4-(5-chloro-2-oxoindolin-3-yl)-1,5-dip-tolyl-1H-
ꢀ
(0.8 mmol) and anhydrous zinc chloride (0.5 mmol) were added. pyrrole-3-carboxylate (4d). White solid, 70%, m.p. 240–242 C;
The mixture was reuxed for six hours. The solvent was 1H NMR (400 MHz, DMSO-d6) d: keto-form: 10.50 (s, 1H, NH),
removed under reduced pressure. The residue was titrated with 7.67 (s, 1H, CH), 7.19–7.12 (m, 8H, ArH), 6.96 (brs, 1H, ArH),
alcohol to give the pure product.
6.83 (d, J ¼ 8.4 Hz, 1H, ArH), 4.37 (s, 1H, CH), 3.41 (s, 3H,
Methyl 5-(4-chlorophenyl)-4-(2-oxoindolin-3-yl)-1-p-tolyl-1H- OCH3), 2.29 (s, 3H, CH3), 2.27 (s, 3H, CH3); enol-form: 10.21 (s,
ꢀ
pyrrole-3-carboxylate (4a). White solid, 76%, m.p. 250–252 C; 1H, NH), 7.12 (brs, 1H, ArH), 7.08 (d, J ¼ 8.0 Hz, 2H, ArH), 6.70
1H NMR (400 MHz, DMSO-d6) d: keto-form: 10.39 (s, 1H, NH), (brs, 2H, ArH), 6.79 (d, J ¼ 7.2 Hz, 2H, ArH), 6.64 (d, J ¼ 8.0 Hz,
7.70 (s, 1H, CH), 7.43 (d, J ¼ 8.4 Hz, 2H, ArH), 7.28 (d, J ¼ 8.4 Hz, 1H, ArH), 6.42 (d, J ¼ 6.8 Hz, 2H, ArH), 5.59 (s, 1H, CH), 3.81 (s,
2H, ArH), 7.19 (d, J ¼ 8.4 Hz, 2H, ArH), 7.13 (d, J ¼ 8.0 Hz, 2H, 3H, OCH3), 2.24 (s, 3H, CH3), 2.15 (s, 3H, CH3). Keto–enol ¼
ArH), 7.03–7.00 (m, 1H, ArH), 6.94 (d, J ¼ 7.2 Hz, 1H, ArH), 6.85 5 : 1. 13C NMR (100 MHz, DMSO-d6) d: 178.0, 163.8, 142.5, 138.0,
(t, J ¼ 8.4 Hz, 2H, ArH), 4.35 (s, 1H, CH), 3.37 (s, 3H, OCH3), 2.30 137.4, 136.7, 136.7, 133.4, 131.0, 130.0, 129.6, 128.9, 127.5,
(s, 3H, CH3); enol-form: 10.13 (s, 1H, NH), 7.73 (s, 1H, CH), 7.43 127.4, 125.9, 125.3, 123.1, 116.7, 113.4, 110.5, 56.5, 50.7, 45.2,
(d, J ¼ 8.4 Hz, 2H, ArH), 7.28 (d, J ¼ 8.4 Hz, 2H, ArH), 7.19 (d, J ¼ 21.2, 20.9, 19.0; IR (KBr) n: 3341, 3184, 3130, 3034, 2948, 2921,
8.4 Hz, 2H, ArH), 7.13 (d, J ¼ 8.0 Hz, 2H, ArH), 7.03–7.00 (m, 1H, 2857, 1695, 1653, 1618, 1558, 1518, 1476, 1257, 1231, 1199,
62824 | RSC Adv., 2014, 4, 62817–62826
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