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Helvetica Chimica Acta – Vol. 96 (2013)
J ¼ 8.5, 4 arom. H); 6.84 (d, J ¼ 8.5, 4 arom. H); 7.02 (d, J ¼ 8.5, 4 arom. H). 13C-NMR (74.4 MHz,
CDCl3): 31.1; 31.2 (Me); 34.1; 34.3 (C); 52.1 (MeO); 123.3; 124.0; 129.4; 130.5 (CH); 131.7; 135.8; 135.9;
139.2; 143.6; 148.32; 149.2 (C); 169.0 (CO). GC/EI-MS (70 eV): 723 ([M þ H]þ, 47), 722 (Mþ, 100), 676
(11), 661 (12), 531 (23), 489 (11), 475 (14). HR-EI-MS (70 eV): 722.433526 (Mþ, C50H58O4þ ; calc.
722.43296).
Dimethyl 3,4,5,6-Tetrakis(4-methoxyphenyl)benzene-1,2-dicarboxylate (5f). From 3 (75 mg,
0.147 mmol), 4f (100 mg, 0.66 mmol), [Pd(Ph3P)4] (20 mg, 12 mol-%, 0.021 mmol), K2CO3 (2m,
1.0 ml), and 1,4-dioxane (4 ml): 5f (81 mg, 90%). White solid. M.p. 253 – 2558. IR (KBr): 3039w,
3003w, 2952w, 1742s, 1721s, 1609s, 1575m, 1515s, 1461m, 1435m, 1417m, 1343m, 1306w, 1286s, 1237s,
1194m, 1174s, 1151m, 1109m, 1064s, 1029s, 968m, 794s, 546m. 1H-NMR (300 MHz, CDCl3): 3.43 (MeO);
3.54 (MeO); 3.64 (MeO); 6.34 (d, J ¼ 8.7, 4 arom. H); 6.50 (d, J ¼ 8.7, 4 arom. H); 6.60 (d, J ¼ 8.7, 4 arom.
H); 6.85 (d, J ¼ 8.7, arom. H). 13C-NMR (74.4 MHz, CDCl3): 52.2; 54.9; 55.0 (MeO); 112.5; 112.9; 130.8
(CH); 131.3; 131.3 (C); 131.9 (CH); 132.1; 138.9; 143.3; 157.3; 158.1 (C); 168.9 (CO). GC/EI-MS
(70 eV): 619 ([M þ H]þ, 35), 618 (Mþ, 100), 512 (8), 262 (14). HR-EI-MS (70 eV): 618.224059 (Mþ,
C38H34Oþ8 ; calc. 618.22482).
Dimethyl 3,4,5,6-Tetrakis(4-fluorophenyl)benzene-1,2-dicarboxylate (5g). From
3 (75 mg,
0.15 mmol), 4g (92 mg, 0.66 mmol), [Pd(Ph3P)4] (20 mg, 12 mol-%, 0.021 mmol), K2CO3 (2m, 1.0 ml),
and 1,4-dioxane (4 ml): 5g (66 mg, 80%). White solid. M.p. 198 – 2008. IR (KBr): 3065w, 3052w, 3005w,
1740s, 1727s, 1604s, 1512s, 1439s, 1421m, 1395m, 1340s, 1256s, 1218s, 1197s, 1177m, 1162s, 1154s, 1095s,
1056s, 1013m, 967s, 860m, 845m, 829s, 803s, 545s, 530s. 1H-NMR (300 MHz, CDCl3): 3.45 (s, 2 MeO); 6.55
(d, J ¼ 7.0, 8 arom. H); 6.75 – 6.80 (m, 4 arom. H); 6.88 – 6.93 (m, 4 arom. H). 13C-NMR (74.4 MHz,
CDCl3): 52.4 (MeO); 113.7 (d, J ¼ 21.4); 114.1 (d, J ¼ 21.4); 130.6 (d, J ¼ 8.0); 131.6 (d, J ¼ 8.0, CH);
131.9; 133.5 (d, J ¼ 3.6); 133.6 (d, J ¼ 3.6); 138.0; 142.0; 160.4 (d, J(C,F) ¼ 245.5, CF); 161.1 (d, J(C,F) ¼
245.5 Hz, CF); 167.6 (CO). GC/EI-MS (70 eV): 571 ([M þ H]þ, 31), 570 (Mþ, 100), 540 (15), 539 (47),
507 (22). HR-EI-MS (70 eV): 570.144951 (Mþ, C34H22 F4O4þ ; calc. 570.14487).
Dimethyl 3,4,5,6-Tetrakis(4-chlorophenyl)benzene-1,2-dicarboxylate (5h). From
3 (75 mg,
0.15 mmol), 4h (103 mg, 0.66 mmol), [Pd(Ph3P)4] (20 mg, 12 mol-%, 0.021 mmol), K2CO3 (2m,
1.0 ml), and 1,4-dioxane (4 ml): 5h (72 mg, 77%). Yellow solid. M.p. 284 – 2868. IR (KBr): 3032w,
2993w, 2949w, 1744s, 1718s, 1492s, 1437s, 1393m, 1340s, 1332s, 1244s, 1223s, 1195s, 1171s, 1152m, 1089s,
1
1059s, 1013s, 966m, 914m, 862s, 834s, 813s, 782s, 752s, 743s, 732s. H-NMR (300 MHz, CDCl3): 3.45 (s,
2 MeO); 6.53 (d, J ¼ 8.5, 4 arom. H); 6.82 – 6.88 (m, 8 arom. H); 7.06 (d, J ¼ 8.5, arom. H). 13C-NMR
(62.9 MHz, CDCl3): 51.5 (MeO); 126.7; 127.0; 129.8; 130.8 (CH); 131.6; 132.4; 135.3; 135.5; 137.4; 141.0
(C); 166.9 (CO). GC/EI-MS (70 eV): 640 (M(35Cl37Cl3)þ, 10), 638 (M(35Cl237Cl2)þ, 46), 636
(M(35Cl337Cl)þ, 100), 634 (M(35Cl4)þ, 68), 607 (11), 605 (22), 603 (17). HR-EI-MS (70 eV):
638.020486 (for M(35Cl237Cl2)þ, C34H22 Cl4þ4 , calc. 638.02077), 636.021757 (M(35Cl37Cl3)þ, C34H22Cl4Oþ4 ;
calc. 636.02372), 634.025016 (M(35Cl337Cl)þ, C34H22 Cl4Oþ4 ;calc. 634.0266).
Dimethyl 3,4,5,6-Tetrakis[4-(trifluoromethyl)phenyl]benzene-1,2-dicarboxylate (5i). From 3 (75 mg,
0.15 mmol), 4i (125 mg, 0.66 mmol), [Pd(Ph3P)4] (20 mg, 12 mol-%, 0.021 mmol), K2CO3 (2m, 1.0 ml),
and 1,4-dioxane (4 ml): 5i (82 mg, 73%). White solid. M.p. 234 – 2358. IR (KBr): 2959w, 1737s, 1693w,
1617m, 1441m, 1405m, 1321s, 1243m, 1231m, 1158s, 1106s, 1064s, 1052s, 1018s, 971m, 890w, 883w, 869m,
847m, 825m, 814m, 797m, 711m, 703m, 613s. 1H-NMR (300 MHz, CDCl3): 3.43 (s, 2 MeO); 6.74 (d, J ¼
8.0, 4 arom. H); 7.10 (t, J ¼ 8.1, 16.5, 8 arom. H); 7.36 (d, J ¼ 8.1, 4 arom. H). 13C-NMR (74.4 MHz,
CDCl3): 52.6 (MeO); 123.5 (q, J(C,F) ¼ 270.5, CF3); 123.7 (q, J(C,F) ¼ 270.5, CF3); 124.4 (d, J(C,F) ¼
3.7, CH); 124.8 (d, J(C,F) ¼ 3.7, CH); 129.2 (q, J(C,F) ¼ 32.4, C); 129.7 (q, J(C,F) ¼ 32.4, C); 129.9,
130.8 (CH); 138.6; 141.1; 141.4; 141.4; 141.7 (C); 167.5 (CO). 19F-NMR (282.40 MHz, CDCl3): ꢀ 62.96;
ꢀ 62.81 (CF3). GC/EI-MS (70 eV): 771 ([M þ H]þ, 34), 770 (Mþ, 94), 751 (11), 740 (35), 739 (100), 707
(12). HR-EI-MS (70 eV): 770.130669 (Mþ, C38H22F12O4þ ; calc. 770.13210).
Dimethyl 3,4,5,6-Tetraphenylbenzene-1,2-dicarboxylate (5j). From 3 (75 mg, 0.15 mmol), 4j (80 mg,
0.66 mmol), [Pd(Ph3P)4] (20 mg, 12 mol-%, 0.021 mmol), K2CO3 (2m, 1.0 ml), and 1,4-dioxane (4 ml): 5j
(57 mg, 80%). White solid. M.p. 215 – 2178. IR (KBr): 3080w, 3052w, 3026w, 3004w, 2950w, 1720s, 1496m,
1440m, 1434m, 1410m, 1335m, 1241s, 1225s, 1196m, 1171m, 1158m, 1153m, 1065s, 1030m, 999m, 963m,
912m, 886m, 841m, 820m, 799m, 761s, 716s, 708s, 697s, 567s. 1H-NMR (300 MHz, CDCl3): 3.40 (s, 2
MeO); 6.60 – 6.64 (m, 4 arom. H); 6.76 – 6.78 (m, 6 arom. H); 6.94 – 6.98 (m, 4 arom. H); 7.01 – 7.04 (m, 6