PAPER
The Preparation of Rigid Linear Di- (and Tri-)catechol Derivatives
1559
2,2’,3,3’-Tetramethoxy-1,1’-biphenyl (8)
13C NMR (CDCl3): d = 153.2 (C), 146.7 (C), 137.0 (C), 135.7 (C),
129.0 (CH), 124.1 (CH), 122.7 (CH), 111.5 (CH), 60.7 (CH3), 56.0
(CH3).
3-Bromoveratrole (7;9 650 mg, 3.0 mmol) and Pd(PPh3)4 (120 mg,
0.01 mmol) were dissolved in toluene (20 mL) and successively 2
M aq Na2CO3 solution (3.5 mL) and 2,3-dimethoxyphenylboronic
acid (6; 560 mg, 3.07 mmol) in EtOH (5 mL) were added. After re-
fluxing overnight the mixture was washed with aq Na2CO3 solution,
dried (MgSO4) and solvent was removed under vacuum. The crude
product of 8 was purified by column chromatography (silica gel,
CH2Cl2); yield: 508 mg (61%); yellow solid; mp 98 °C (CH2Cl2).
IR (KBr): n = 3447, 3104, 3007, 2841, 1597, 1579, 1480, 1427,
1398, 1268, 1228, 1017, 1005, 838, 754, 652 cm-1.
UV/vis (MeOH): l (e) = 204 (53800), 266 nm (25600).
MS: m/z (%) = 350 (100) [M]+.
HRMS (EI, 70 eV): C22H22O4 (350.4): m/z calcd: M 350.1518;
1H NMR (CDCl3): d = 7.09 (t, J = 7.9 Hz, 2 H), 6.95 (dd, J = 7.9,
1.5 Hz, 2 H), 6.89 (dd, J = 7.9, 1.5 Hz, 2 H), 3.92 (s, 6 H), 3.68 (s,
6 H).
13C NMR (CDCl3): d = 152.8 (C), 146.8 (C), 132.9 (C), 123.3 (CH),
123.2 (CH), 111.7 (CH), 60.6 (CH3), 55.8 (CH3).
found M+ 350.1530.
C22H22O4 (350.4)
calcd
found
C 75.41
75.83
H 6.33
6.44
2,2”’,3,3’”-Tetramethoxy-1,1’:4’,1”:4”,1’”-quaterphenyl (12)
Yield: 57%; yellow solid; mp 156 °C (CH2Cl2).
1H NMR (CDCl3): d = 7.72 (d, J = 8.1 Hz, 4 H), 7.66 (d, J = 8.1 Hz,
4 H), 7.14 (dd, J = 8.1, 7.8 Hz, 2 H), 7.02 (dd, J = 7.8, 1.6 Hz, 2 H),
6.95 (dd, J = 8.1, 1.6 Hz, 2 H), 3.93 (s, 6 H), 3.64 (s, 6 H).
13C NMR (CDCl3): d = 153.2 (C), 146.7 (C), 139.5 (C), 137.2 (C),
135.5 (C), 129.7 (CH), 126.7 (CH), 124.1 (CH), 122.6 (CH), 111.6
(CH), 60.7 (CH3), 56.0 (CH3).
IR (KBr): n = 2999, 2958, 1591, 1578, 1465, 1420, 1294, 1141,
1006, 764, 664 cm-1.
UV/vis (MeOH): l (e) = 204 (46000), 277 nm (3500).
MS: m/z (%) = 274 (14) [M]+, 138 (100).
HRMS (EI, 70 eV): C16H18O4 (274.3): m/z calcd: M 274.1205;
found M+ 274.1215.
IR (KBr): n = 2946, 2834, 1598, 1423, 1315, 1259, 1229, 1171,
C16H18O4 (274.3)
calcd
found
C 70.06
69.96
H 6.61
6.70
854, 788, 750, 641 cm-1.
UV/vis (MeOH/qualitative): l = 209, 287 nm.
MS: m/z (%) = 426 (100) [M]+.
1,1’-Biphenyl-2,2’,3,3’-tetrol (1)
The tetramethoxy derivative 8 (198 mg, 0.72 mmol) was dissolved
in CH2Cl2 (20 mL) and BBr3 (3.5 mL, 1 M in CH2Cl2) was added at
0 °C. The mixture was stirred overnight at r.t. and after addition of
MeOH (5 mL) the solvent was removed under vacuum. The residue
was dissolved in Et2O (30 mL), washed with H2O (3 × 30 mL),
dried (MgSO4) and the solvent was removed in vacuum; yield: 172
mg (quant); light brown solid; mp 214 °C (dec., Et2O).
1H NMR (CD3OD): d = 6.81 (dd, J = 7.5, 2.5 Hz, 2 H), 6.79 (t,
J = 7.5 Hz, 2 H), 6.76 (dd, J = 7.5, 2.5 Hz, 2 H).
13C NMR (CD3OD): d = 147.4 (C), 142.9 (C), 128.3 (C), 123.1
(CH), 121.6 (CH), 115.2 (CH).
HRMS (EI, 70 eV): C28H26O4 (426.5): m/z calcd: M 426.1831;
found M+ 426.1810.
C28H26O4 (426.5) calcd
found
C 78.85
78.28
H 6.14
6.18
2,2’,2”,3,3’,3”-Hexamethoxy-1,1’:4’,1”-terphenyl (14)
Yield: 28%; white solid; mp 126 °C (CH2Cl2).
1H NMR (CDCl3): d = 7.11 (t, J = 7.9 Hz, 2 H), 7.03 (s, 2 H), 6.95
(m, 4 H), 3.92 (s, 6 H), 3.72 (s, 6 H), 3.68 (s, 6 H).
13C NMR (CDCl3): d = 152.8 (C), 150.8 (C), 146.9 (C), 132.9 (C),
132.4 (C), 125.4 (CH), 123.5 (CH), 123.3 (CH), 111.7 (CH), 60.7
(CH3), 60.6 (CH3), 55.9 (CH3).
IR (KBr): n = 3454, 3328, 1622, 1595, 1465, 1374, 1217, 1072,
965, 746, 724 cm-1.
IR (KBr): n = 3444, 2962, 2837, 1601, 1476, 1399, 1269, 1225,
1140, 1010, 833, 785 cm-1.
UV/vis (MeOH): l (e) = 213 (37500), 249 (10800), 286 nm (4500).
MS: m/z (%) = 218 (100) [M]+.
UV/vis (MeOH): l (e) = 217 (62300), 249 nm (17100).
MS: m/z (%) = 410 (100) [M]+.
HRMS (EI, 70 eV): C12H10O4 (218.2): m/z calcd: M 218.0579;
found M+ 218.0570.
HRMS (EI, 70 eV): C24H26O6 (410.5): m/z calcd: M 410.1729;
found M+ 410.1749.
C12H10O4∑1/3 H2O (224.2) calcd
C 64.28 H 4.80
64.29 4.76
found
C24H26O6 (410.5) calcd
found
C 70.23
70.01
H 6.38
6.45
Suzuki Coupling of Dibromides 9, 11, and 13 with 2,3-
Dimethoxyphenylboronic Acid (6); General Procedure
The aryl dibromide (9, 11, or 138; 3.5 mmol) and Pd(PPh3)4 (0.17
mmol) were dissolved in toluene and 2 M aq Na2CO3 solution (3.5
mL) was added. Boronic acid 6 (2 equiv, 7 mmol dissolved in a
small amount of EtOH) was added and the mixture was heated to re-
flux overnight. After cooling to r.t. the solution was washed with
H2O, dried (MgSO4) and the solvent was removed in vacuum. The
crude product was purified by column chromatography (silica gel,
CH2Cl2).
1,1’:4’,1”-Terphenyl-2,2”,3,3”-tetrol (2)
Ether cleavage was performed as described for the preparation of 1.
Yield: 91%; yellow solid; mp 163 °C (Et2O).
1H NMR (CD3OD): d = 7.59 (s, 4 H), 6.82 (dd, J = 7.6, 2.0 Hz, 2 H),
6.79 (dd, J = 7.6, 2.0 Hz, 2 H), 6.76 (t, J = 7.6 Hz, 2 H).
13C NMR (CD3OD): d = 146.7 (C), 143.7 (C), 138.0 (C), 130.1 (C),
129.9 (CH) 122.3 (CH), 120.7 (CH), 115.0 (CH).
IR (KBr): n = 3491, 3328, 1616, 1470, 1357, 1301, 1262, 845, 779,
2,2”,3,3”-Tetramethoxy-1,1’:4’,1”-terphenyl (10)
Yield: 38%; yellow solid; mp 181-182 °C (CH2Cl2).
1H NMR (CDCl3): d = 7.62 (s, 4 H), 7.13 (t, J = 7.9 Hz, 2 H), 7.03
(dd, J = 7.9, 1.5 Hz, 2 H), 6.94 (dd, J = 7.9, 1.5 Hz, 2 H), 3.93 (s, 6
H), 3.64 (s, 6 H).
715 cm-1.
UV/vis (MeOH): l (e) = 203 (57900), 269 nm (24500).
MS: m/z (%) = 294 (100) [M]+.
HRMS (EI, 70 eV): C18H14O4 (294.3): m/z calcd: M 294.0892;
found M+ 294.0879.
Synthesis 2000, No. 11, 1557–1560 ISSN 0039-7881 © Thieme Stuttgart · New York