PAPER
Low-Valent Titanium Reagent in the Synthesis of Pyrroles
3121
IR (KBr): 3057, 3029, 2919, 1600, 1567, 1495, 1450, 1371, 1330,
1257, 1210, 1176, 1066, 1050, 1030, 998, 943, 920, 906, 879, 842,
820, 771, 757, 702, 691 cm–1.
Anal. Calcd for C30H23NO3: C, 80.88; H, 5.20; N, 3.14. Found: C,
80.92; H, 5.06; N, 3.31.
2-(4-Bromophenyl)-3,5-diphenyl-1-(p-tolyl)-1H-pyrrole (3l)
Solid; mp 183–184 °C.
1H NMR (400 MHz, DMSO-d6): d = 7.28–7.15 (m, 11 H, ArH),
7.13–7.08 (m, 1 H, ArH), 7.07–6.96 (m, 5 H, ArH), 6.74 (s, 1 H, H-
4), 2.24 (s, 6 H, 2 × CH3).
IR (KBr): 3057, 3030, 2922, 1599, 1513, 1488, 1481, 1460, 1405,
1376, 1333, 1298, 1247, 1202, 1181, 1106, 1073, 1028, 1010, 943,
914, 825, 810, 758, 696 cm–1.
1H NMR (400 MHz, DMSO-d6): d = 7.40 (d, J = 8.4 Hz, 2 H, ArH),
7.26–7.12 (m, 10 H, ArH), 7.07 (d, J = 8.0 Hz, 2 H, ArH), 7.03 (d,
J = 8.4 Hz, 2 H, ArH), 6.99 (d, J = 8.4 Hz, 2 H, ArH), 6.74 (s, 1 H,
H-4), 2.25 (s, 3 H, CH3).
Anal. Calcd for C30H24ClN: C, 83.03; H, 5.57; N, 3.23. Found: C,
83.28; H, 5.41; N, 3.05.
2-(Benzo[d][1,3]dioxol-6-yl)-1-(3-chloro-4-methylphenyl)-3,5-
diphenyl-1H-pyrrole (3h)
Solid; mp 188–189 °C.
IR (KBr): 3057, 3026, 2891, 1599, 1559, 1501, 1485, 1462, 1444,
1371, 1330, 1234, 1178, 1140, 1106, 1088, 1042, 999, 939, 905,
880, 861, 842, 823, 773, 757, 702, 690 cm–1.
Anal. Calcd for C29H22BrN: C, 75.00; H, 4.77; N, 3.02. Found: C,
75.21; H, 4.59; N, 2.96.
1-(3-Chloro-4-methylphenyl)-2-(4-methoxyphenyl)-3,5-diphe-
nyl-1H-pyrrole (3m)
Solid; mp 164–166 °C.
1H NMR (400 MHz, DMSO-d6): d = 7.28–7.10 (m, 12 H, ArH),
7.02 (dd, J = 2.0, 8.0 Hz, 1 H, ArH), 6.79 (d, J = 8.0 Hz, 1 H, ArH),
6.74 (d, J = 8.4 Hz, 1 H, ArH), 6.73 (s, 1 H, H-4), 6.64 (dd,
J = 1.6, 8.0 Hz, 1 H, ArH), 5.99 (s, 2 H, OCH2O), 2.26 (s, 3 H, CH3).
IR (KBr): 3059, 3028, 2930, 2832, 1601, 1569, 1559, 1508, 1491,
1464, 1437, 1371, 1286, 1246, 1174, 1068, 1051, 1031, 917, 882,
844, 829, 797, 774, 760, 699 cm–1.
1H NMR (400 MHz, DMSO-d6): d = 7.25–7.16 (m, 11 H, ArH),
7.13–7.09 (m, 1 H, ArH), 7.07 (d, J = 8.8 Hz, 2 H, ArH), 6.99 (d,
J = 8.4 Hz, 1 H, ArH), 6.81 (d, J = 8.8 Hz, 2 H, ArH), 6.75 (s, 1 H,
H-4), 3.71 (s, 3 H, CH3O), 2.24 (s, 3 H, CH3).
Anal. Calcd for C30H22ClNO2: C, 77.66; H, 4.78; N, 3.02. Found: C,
77.42; H, 4.56; N, 3.21.
2-(Benzo[d][1,3]dioxol-6-yl)-1-(4-fluorophenyl)-3,5-diphenyl-
1H-pyrrole (3i)
Solid; mp 164–166 °C.
IR (KBr): 3067, 3029, 2898, 1600, 1560, 1504, 1482, 1467, 1438,
1397, 1381, 1324, 1230, 1179, 1150, 1107, 1036, 938, 914, 881,
864, 844, 813, 762, 727, 696 cm–1.
1H NMR (400 MHz, DMSO-d6): d = 7.27–7.09 (m, 14 H, ArH),
6.78 (d, J = 8.0 Hz, 1 H, ArH), 6.76 (s, 1 H, H-4), 6.69 (d, J = 1.6
Hz, 1 H, ArH), 6.61 (dd, J = 1.6, 8.0 Hz, 1 H, ArH), 5.98 (s, 2 H,
OCH2O).
MS: m/z = 449 (M+, 100%).
Anal. Calcd for C30H24ClNO: C, 80.08; H, 5.38; N, 3.11. Found: C,
79.94; H, 5.20; N, 3.17.
1-(3-Chlorophenyl)-2-(4-methylphenyl)-3,5-diphenyl-1H-pyr-
role (3n)
Solid; mp 151–153 °C.
MS: m/z = 433 (M+, 100%).
IR (KBr): 3060, 3027, 2916, 1592, 1508, 1479, 1450, 1428, 1367,
1319, 1184, 1103, 1075, 1020, 913, 886, 825, 789, 770, 758, 698
cm–1.
1H NMR (400 MHz, DMSO-d6): d = 7.32–7.11 (m, 13 H, ArH),
7.08–7.01 (m, 5 H, ArH), 6.77 (s, 1 H, H-4), 2.25 (s, 3 H, CH3).
Anal. Calcd for C29H20FNO2: C, 80.35; H, 4.65; N, 3.23. Found: C,
80.14; H, 4.40; N, 3.32.
2-(4-Bromophenyl)-1-(4-fluorophenyl)-3,5-diphenyl-1H-pyr-
role (3j)
Solid; mp 181–182 °C.
MS: m/z = 419 (M+, 100%).
Anal. Calcd for C29H22ClN: C, 82.94; H, 5.28; N, 3.34. Found: C,
83.16; H, 5.08; N, 3.50.
IR (KBr): 3055, 3027, 1600, 1510, 1475, 1440, 1407, 1376, 1226,
1199, 1179, 1150, 1072, 1010, 942, 911, 843, 820, 757, 716, 696
cm–1.
1H NMR (400 MHz, DMSO-d6): d = 7.42 (d, J = 8.4 Hz, 2 H, ArH),
7.28–7.10 (m, 14 H, ArH), 7.04 (d, J = 8.4 Hz, 2 H, ArH), 6.77 (s,
1 H, H-4).
2-(4-Bromophenyl)-1-(3-chlorophenyl)-3,5-diphenyl-1H-pyr-
role (3o)
Solid; mp 144–146 °C.
IR (KBr): 3058, 3026, 1590, 1508, 1493, 1480, 1401, 1388, 1374,
1322, 1179, 1099, 1072, 1028, 1009, 944, 912, 886, 829, 787, 758,
740, 718, 696 cm–1.
Anal. Calcd for C28H19BrFN: C, 71.80; H, 4.09; N, 2.99. Found: C,
71.93; H, 3.98; N, 3.37.
1H NMR (400 MHz, DMSO-d6): d = 7.44 (d, J = 8.4 Hz, 2 H, ArH),
7.36–7.15 (m, 13 H, ArH), 7.10–7.06 (m, 3 H, ArH), 6.78 (s, 1 H,
H-4).
2-(Benzo[d][1,3]dioxol-6-yl)-1-(4-methoxyphenyl)-3,5-diphe-
nyl-1H-pyrrole (3k)
Solid; mp 162–163 °C.
MS: m/z = 485 (M+ + 2, 100%).
IR (KBr): 3051, 2969, 2890, 1601, 1556, 1512, 1470, 1436, 1403,
1373, 1342, 1290, 1231, 1176, 1137, 1106, 1085, 1069, 1037, 974,
933, 876, 864, 840, 816, 767, 749, 699 cm–1.
Anal. Calcd for C28H19BrClN: C, 69.37; H, 3.95; N, 2.89. Found: C,
69.24; H, 4.07; N, 2.83.
1H NMR (400 MHz, DMSO-d6): d = 7.26–7.10 (m, 10 H, ArH),
7.07 (d, J = 8.8 Hz, 2 H, ArH), 6.81 (d, J = 8.8 Hz, 2 H, ArH), 6.76
(d, J = 7.6 Hz, 1 H, ArH), 6.72 (s, 1 H, H-4), 6.68 (d, J = 1.6 Hz, 1
H, ArH), 6.60 (dd, J = 1.6, J = 8.0 Hz, 1 H, ArH), 5.98 (s, 2 H,
OCH2O), 3.70 (s, 3 H, CH3O).
3,5-Bis(4-chlorophenyl)-1-(4-fluorophenyl)-2-(p-tolyl)-1H-pyr-
role (3p)
Solid; mp 228–229 °C.
IR (KBr): 3050, 3025, 2921, 1554, 1503, 1485, 1429, 1401, 1374,
1328, 1264, 1222, 1204, 1176, 1151, 1091, 1039, 1011, 966, 944,
843, 797, 762, 726 cm–1.
MS: m/z = 445 (M+, 100%).
Synthesis 2007, No. 20, 3117–3124 © Thieme Stuttgart · New York