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Helvetica Chimica Acta Vol. 88 (2005)
(d); 151.1 (s); 162.1 (s); 192.7 (s). MS: 447 (100, [M H] ), 446 (47, M ), 341 (7, [M À C7H5O] ), 105 (15,
C7H5O ). Anal. calc. for C29H22N2O3 (446.5): C 78.01, H 4.97, N 6.27; found: C 77.67, H 4.87, N 6.46.
Ethyl 1-(4-Methoxybenzoyl)-2-phenyl-7-(pyridin-4-yl)indolizine-3-carboxylate (4h). According to G.P. 1:
201 mg (42%) of 4h. Pale-yellow crystals, M.p. 272 2738. UV/VIS (CH2Cl2): 248 (30000), 356 (18600). IR
(KBr): 3059, 2979, 2886, 1680, 1636, 1599, 1573, 1510, 1482, 1466, 1415, 1396, 1380, 1257, 1228, 1186, 1168, 1150,
1078, 1031, 794, 613. 1H-NMR (CD2Cl2, 300 MHz): 0.98 (t, J 7.3, 3 H); 3.75 (s, 3 H); 4.14 (q, J 7.3, 2 H); 6.66
(dd, J 1.8, 6.6, 2 H); 7.13 7.16 (m, 3 H); 7.21 7.25 (m, 2 H); 7.30 (dd, J 1.8, 7.3, 1 H); 7.53 (dd, J 2.2, 6.9,
2 H); 7.58 (dd, J 1.5, 4.4, 2 H); 8.23 (m, 1 H); 8.67 (dd, J 1.5, 4.4, 2 H); 9.70 (dd, J 1.1, 7.7, 1 H). 13C-NMR
(CD2Cl2, 75 MHz): 13.9 (q); 55.8 (q); 60.6 (t); 113.4 (d); 116.7 (s); 117.2 (d); 121.4 (d); 127.3 (d); 127.5 (d); 128.0
(d); 128.6 (d); 129.6 (d); 131.3 (d); 131.8 (d); 132.4 (s); 134.7 (s); 134.8 (s); 138.3 (s); 139.0 (s); 145.6 (s); 150.9
(d); 154.2 (s); 162.1 (s); 163.0 (s); 191.2 (s). MS: 477 (100, [M H] ), 476 (49, M ), 431 (5, [M À C2H5O] ), 369
(6, [M À C7H7O] ), 341 (4, [M À C8H7O2] ). Anal. calc. for C30H24N2O4 (476.5): C 75.62, H 5.08, N 5.88; found:
C 75.62, H 5.12, N 5.92.
[3-(4-Methoxybenzoyl)-2-phenyl-7-(pyridin-4-yl)indolizin-1-yl](4-nitrophenyl)methanone (4i). According
to G.P. 1: 226 mg (41%) of 4i. Yellow solid. M.p. 231 2328. UV/VIS (CH2Cl2): 246 (35400), 274 (36500), 384
(25400). IR (KBr): 3068, 1600, 1573, 1520, 1477, 1419, 1379, 1347, 1315, 1257, 1226, 1198, 1169, 1111, 1074, 1053,
1
1028, 927, 907, 866, 849, 793, 764, 749, 730, 709, 666, 633, 613. H-NMR (CD2Cl2, 300 MHz): 3.65 (s, 3 H); 6.48
(dd, J 2.1, 6.9, 2 H); 6.71 6.78 (m, 3 H); 6.83 6.86 (m, 2 H); 7.37 7.42 (m, 3 H); 7.47 (dd, J 2.1, 6.9, 2 H);
7.69 (d, J 5.2, 2 H); 7.80 (dd, J 1.7, 6.9, 2 H); 8.75 (m, 3 H); 9.49 (dd, J 0.7, 7.3, 1 H). 13C-NMR (CD2Cl2,
75 MHz): 55.7 (q); 113.2 (d); 113.9 (s); 114.2 (d); 117.3 (d); 121.5 (d); 122.9 (d); 127.7 (d); 128.4 (d); 130.3 (d);
131.5 (s); 132.1 (d); 132.2 (d); 133.4 (s); 137.3 (s); 138.6 (s); 139.5 (s); 145.3 (s); 145.4 (s); 149.1 (s); 151.1 (d);
154.3 (s); 163.1 (s); 187.3 (s); 190.9 (s). MS: 554 (73, [M H] ), 553 (42, M ), 538 (5, [M À CH3] ), 508 (3,
[M H À NO2] ), 154 (100, [M À C7H4NO3] ). Anal. calc. for C34H23N3O5 (553.6): C 73.77, H 4.19, N 7.59;
found: C 73.34, H 4.23, N 7.52.
{2-{{[(1,1-Dimethylethyl)dimethylsilyl]oxy}methyl}-7-(pyridin-4-yl)indolizin-1,3-diyl}bis[(4-methoxyphen-
yl)methanone] (4j). According to G.P. 1: 320 mg (53%) of 4j. Yellow solid, M.p. 178 1798. UV/VIS (CH2Cl2):
246 (32200), 384 (27200). IR (KBr): 2954, 2929, 2855, 1600, 1573, 1509, 1472, 1437, 1370, 1311, 1259, 1259, 1167,
1142, 1072, 1058, 1029, 976, 912, 872, 839, 776, 632, 611. 1H-NMR (CD2Cl2, 300 MHz): À 0.38 (s, 6 H); 0.61 (s,
9 H); 3.85 (s, 3 H); 3.87 (s, 3 H); 4.50 (s, 2 H); 6.96 (d, J 2.1, 1 H); 6.98 (d, J 2.4, 2 H); 7.00 (d, J 2.1, 1 H);
7.15 (dd, J 1.7, 7.3, 1 H); 7.48 (dd, J 1.4, 4.5, 2 H); 7.78 (d, J 2.1, 1 H); 7.80 (s, 2 H); 7.83 (d, J 2.1, 1 H); 7.87
(m, 1 H); 8.62 (d, J 5.6, 2 H); 9.15 (dd, J 1.0, 7.7, 1 H). 13C-NMR (CD2Cl2, 75 MHz): 6.1 (q); 18.2 (s); 25.7
(q); 55.8 (q); 55.9 (q); 57.7 (t); 112.4 (d); 113.9 (d); 114.2 (d); 115.7 (s); 116.7 (d); 121.1 (d); 122.3 (s); 127.8 (d);
131.6 (d); 131.8 (d); 133.2 (s); 133.4 (s); 134.3 (s); 136.9 (s); 137.6 (s); 145.6 (s); 150.8 (d); 163.6 (s); 163.7 (s);
186.7 (s); 190.9 (s). MS: 607 (100, [M H] ), 606 (12, M ), 549 (82, [M À C4H9] ), 475 (61, [M À C6H15OSi] ),
135 (52, C8H4O2). Anal. calc. for C36H38N2O5Si (606.8): C 71.26, H 6.31, N 4.62; found: C 71.61, H 6.35, N 4.74.
{1-Benzoyl-2-{4-{[(1,1-dimethylethyl)dimethylsilyl]oxy}butyl}-7-(pyridin-4-yl)indolizin-3-yl}(4-methoxy-
phenyl)methanone (4k). According to G.P. 1: 315 mg (51%) of 4k. Yellow solid. M.p. 128 1298. UV/VIS
(CH2Cl2): 248 (32200), 292 (25700), 382 (22600). IR (KBr): 3059, 2953, 2930, 2856, 1597, 1512, 1472, 1447, 1427,
1375, 1344, 1305, 1257, 1233, 1171, 1158, 1106, 1051, 1025, 984, 938, 904, 870, 837, 799, 774, 752, 698, 653, 632, 612,
570, 517. 1H-NMR (CD2Cl2, 300 MHz): À 0.08 (s, 6 H); 0.79 (s, 9 H); 1.06 1.17 (m, 2 H); 1.30 1.48 (m, 2 H);
2.55 (t, J 7.6, 2 H); 3.24 (t, J 6.6, 2 H); 3.88 (s, 3 H); 7.02 (dd, J 1.9, 6.9, 2 H); 7.21 (dd, J 2.2, 7.4, 1 H); 7.48
(dd, J 1.7, 4.6, 2 H); 7.54 7.61 (m, 2 H); 7.69 (tt, J 1.5, 7.4, 1 H); 7.78 (dd, J 0.9, 2.2, 1 H); 7.82 7.87 (m,
4 H); 8.68 (d, J 5.9, 2 H); 9.21 (dd, J 0.7, 7.4, 1 H). 13C-NMR (CD2Cl2, 75 MHz): À 5.4 (q); 18.4 (s); 25.9 (q);
26.6 (t); 28.8 (t); 32.9 (t); 55.8 (q); 62.9 (t); 112.3 (d); 114.2 (d); 115.3 (s); 116.7 (d); 121.1 (d); 123.4 (s); 128.17
(d); 128.8 (d); 129.3 (d); 131.7 (d); 132.4 (d); 132.9 (s); 134.8 (s); 138.8 (s); 140.1 (s); 141.2 (s); 145.5 (s); 150.8
(d); 163.7 (s); 187.2 (s); 192.6 (s). MS: 619 (92, [M H] ), 603 (6, [M À CH3] ), 561 (32, [M À C4H9] ), 135
(100, C8H4O2). Anal. calc. for C38H42N2O4Si (618.8): C 73.75, H 6.84, N 4.53; found: C 73.43, H 6.94, N 4.58.
Synthesis of Biindolizine 6: General Procedure 2 (G.P. 2). In a screw-cap pressure vessel, [Pd(PPh3)2Cl2]
(14 mg, 0.02 mmol) and CuI (7 mg, 0.04 mmol) were dissolved in degassed THF(5 ml). Then acyl chloride
1
(1 mmol), alkyne 2 (1 mmol), as well as Et3N (2 ml) were successively added to the soln. The mixture was stirred
for 2 h at r.t. until the conversion was complete (monitored by TLC). Then the diquaternary salt 5 (0.5 mmol)
was added, and the mixture was stirred at r.t. for 14 h. After complete conversion of the alkynone to the
indolizines (TLC), the mixture was evaporated and the residue purified by CC (silica gel, hexane/AcOEt 4 :1):
pure biindolizine 6 (for exper. details, see Table 5). Further purification was achieved by crystallization.
Ethyl 1,1'-Dibenzoyl-3'-(4-methoxybenzoyl)-2,2'-diphenyl-[7,7'-bisindolizine]-3-carboxylate (6a). Accord-
ing to G.P. 2: 144 mg (18%) of 6a. Yellow solid. M.p. 174 1758. UV/VIS (CH2Cl2): 250 (49500), 280 (48500),