C.J. Blackwell et al. / Dyes and Pigments 95 (2012) 408e420
411
2.3.6. 8-Bromo-3-(4-bromophenyl)-3-phenyl-3H-naphtho[2,1-b]
pyran 22
J ¼ 10.9 Hz, vinyl-H), 5.70 (1H, d, J ¼ 17.6 Hz, vinyl-H), 6.25 (1H, d,
J ¼ 9.96 Hz, 2-H), 6.66 (1H, dd, J ¼ 17.6, 10.9 Hz, vinyl-H), 7.20 (1H, d,
J ¼ 8.8 Hz, 5-H), 7.31 (7H, m, AreH), 7.43 (5H, m, AreH), 7.65 (1H, d,
J ¼ 8.8 Hz, 6-H), 7.70 (1H, d, J ¼ 8.1 Hz, 7-H), 7.95 (1H, d, J ¼ 8.5 Hz,
10-H). Found [M þ H]þ 361.1594; C27H20O requires [M þ H]þ
361.1587.
From
6-bromo-2-naphthol
and
1-(4-bromophenyl)-1-
phenylprop-2-yn-1-ol, as off-white microcrystals after crystal-
lisation from ethyl acetate and hexane, (7.8 g, 76%), mp
176e176.5 ꢀC, nmax 3056, 1909, 1753, 1628, 1580, 1483, 1210, 1069,
1002 cmꢂ1
,
dH 6.21 (1H, d, J ¼ 9.9 Hz, 2-H), 7.18 (1H, d, J ¼ 8.9 Hz, 5-
H), 7.24 (1H, s, AreH), 7.77 (1H, m, AreH), 7.32 (3H, m, AreH), 7.35
(1H, m, AreH), 7.43 (4H, m, AreH), 7.52 (1H, dd, J ¼ 2.0, 9.0 Hz,
AreH), 7.55 (1H, d, J ¼ 8.8 Hz, AreH), 7.80 (1H, d, J ¼ 9.1 Hz, 10-H),
7.86 (1H, d, J ¼ 2.0 Hz, 7-H). Found [M þ H]þ 492.9622; C25H16Br2O
requires [M þ H]þ 492.9620.
2.4.2. 3-Phenyl-3-(2-vinylphenyl)-3H-naphtho[2,1-b]pyran 28
From 3-(2-bromophenyl)-3-phenyl-3H-naphtho[2,1-b]pyran, as
a viscous yellow oil after elution from silica with 10% ethyl acetate
in hexane, (1.7 g, 50%), nmax 3059, 2924, 1632, 1447, 1244, 1083,
1005, 743, 699 cmꢂ1
,
dH 5.27 (1H, dd, J ¼ 11.0, 1.5 Hz, vinyl-H), 5.62
(1H, dd, J ¼ 17.0, 1.5 Hz, vinyl-H), 6.15 (1H, d, J ¼ 10.0 Hz, 2-H), 6.97
(1H, dd, J ¼ 17.3, 11.0 Hz, vinyl-H), 7.21 (1H, d, J ¼ 9.0 Hz, 5-H), 7.35
(8H, m, AreH), 7.50 (4H, m, AreH), 7.58 (1H, d, J ¼ 9.0 Hz, 6-H), 7.68
(1H, d, J ¼ 8.6 Hz, 7-H), 8.01 (1H, d, J ¼ 8.4 Hz, 10-H). Found:
[M þ H]þ 361.1584; C27H20O requires [M þ H]þ 361.1587.
2.3.7. 3,3-Bis(4-bromophenyl)-8-bromo-3H-naphtho[2,1-b]pyran
23
From 6-bromo-2-naphthol and 1,1-bis(4-bromophenyl)prop-2-
yn-1-ol, as beige microcrystals (7.2 g, 77%), mp 151.5e152 ꢀC (lit.
mp 152e153.5 ꢀC [17]), nmax ¼ 3054, 1910, 1749, 1629, 1579, 1482,
1180, 1069, 1003, 959, 816 cmꢂ1
,
dH (d8-PhMe) 5.72 (1H, d,
2.4.3. 3,3-Diphenyl-8-vinyl-3H-naphtho[2,1-b]pyran 29
J ¼ 9.9 Hz, 2-H), 6.82 (1H, d, J ¼ 9.7 Hz, 5-H), 6.93 (1H, d, J ¼ 8.9 Hz,
9-H), 7.09 (5H, m, AreH, 1-H), 7.20 (4H, m, AreH), 7.36 (2H, m, 6-H,
10-H), 7.57 (1H, d, J ¼ 1.8 Hz, 7-H).
From 3,3-diphenyl-8-bromo-3H-naphtho[2,1-b]pyran, as col-
ourless microcrystals (0.8 g, 89%), after elution from silica using 20%
toluene in hexane, mp 124.0e126.1 ꢀC, nmax 3058, 3026, 1631, 1447,
1243, 1217, 1093, 1006, 734, 693 cmꢂ1
,
dH 5.27 (1H, d, J ¼ 10.9 Hz,
2.3.8. 3-(4-Biphenyl)-1-phenyl-3H-naphtho[2,1-b]pyran 24
vinyl-H), 5.80 (1H, d, J ¼ 17.6 Hz, vinyl-H), 6.27 (1H, d, J ¼ 10.0 Hz, 2-
H), 6.81 (1H, dd, J ¼ 17.6, 10.9 Hz, vinyl-H), 7.17 (2H, m, AreH), 7.30
(6H, m, AreH), 7.48 (4H, m, AreH), 7.62 (3H, m, AreH), 7.90 (1H, d,
J ¼ 9.2 Hz, 10-H). Found [M þ H]þ 361.1595; C27H20O requires
[M þ H]þ 361.1587.
From 2-naphthol and 1-(1-biphenyl)-1-phenylprop-2-yn-1-ol,
as pale brown microcrystals after recrystallisation from ethyl
acetate and hexane, (6.4 g, 88%), mp 179.9e180.4 ꢀC, nmax 3057,
1953, 1807, 1633, 1486, 1199, 1003, 807, 750, 725, 691, 483 cmꢂ1
, dH
6.30 (1H, d, J ¼ 10.0 Hz, 2-H), 7.22 (1H, d, J ¼ 8.8 Hz, 5-H), 7.31 (7H,
m, AreH, 1-H), 7.40 (2H, m, AreH), 7.54 (7H, m, AreH), 7.56 (1H, m,
AreH), 7.66 (1H, d, J ¼ 8.8 Hz, 6-H), 7.71 (1H, d, J ¼ 8.4 Hz, 7-H), 7.96
(1H, d, J ¼ 8.4, 10-H). Found [M þ H]þ 411.1745; C31H22O requires
[M þ H]þ 411.1743.
2.5. Preparation of bis- and tris-vinylnaphthopyrans by a Suzuki
coupling protocol
The aryl halide (1 mol equiv) was dissolved in degassed DME
(30 mL), treated with tetrakis (triphenylphosphine) palladium (0)
(12 mol%), and stirred at room temperature under N2 for 20 min.
Potassium carbonate (2 [or 3] mol equiv1), degassed water (8 mL)
and vinyl boronic anhydride pyridine complex (O’Shea’s reagent) (2
[or 3] mol equiv) were added. The reaction was heated under reflux
under N2 for 20 h. The reaction mixture was cooled to ambient
temperature, filtered through a short path of silica with ethyl
acetate (50 mL) and then washed with water (100 mL). The organic
layer was dried (anhydrous Na2SO4) and the solvent evaporated.
The crude residue was purified by flash column chromatography.
2.3.9. 3,3-Diphenyl-3H-naphtho[2,1-b]pyran 25
From 2-naphthol and 1,1-diphenylprop-2-yn-1-ol, as an off-
white solid after elution from silica using 10% ethyl acetate in
hexane, (3.1 g, 67%), mp 158.0e158.3 ꢀC, (lit. mp 158e159 ꢀC [17]),
nmax 3062, 1953, 1809, 1635, 1489, 1215, 1092, 1083, 1008, 804, 750,
726, 695 cmꢂ1
,
dH 6.26 (1H, d J ¼ 9.9 Hz, 2-H), 7.19 (1H, d, J ¼ 8.8 Hz,
5-H), 7.25 (2H, m, Ar-H), 7.29 (6H, m, AreH), 7.48 (5H, m, AreH),
7.65 (1H, d, J ¼ 8.8 Hz, 6-H), 7.71 (1H, d, J ¼ 8.1 Hz, 7-H), 7.95
(1H, d, J ¼ 8.2 Hz, 10-H).
2.4. Preparation of monovinylnaphthopyrans by a Suzuki coupling
protocol
2.5.1. 3,3-Bis(4-vinylphenyl)-3H-naphtho[2,1-b]pyran 30
From 3,3-bis(4-bromophenyl)-3H-naphtho[2,1-b]pyran, as col-
ourless microcrystals after elution from silica using 20% toluene in
hexane, (0.4 g, 50%), mp 114e114.5 ꢀC, nmax 2981, 1918, 1813, 1629,
The aryl halide (1 mol equiv) was dissolved in degassed DME
(20 mL), treated with tetrakis (triphenylphosphine) palladium (0)
(10 mol%), and stirred at room temperature under N2 for 20 min.
Potassium carbonate (1 mol equiv), degassed water (6 mL) and
vinyl boronic anhydride pyridine complex (O’Shea’s reagent
[19,20]) (1 mol equiv) were added. The reaction was heated under
reflux under N2 for 20 h. The reaction mixture was cooled to
ambient temperature, filtered through a short path of silica with
ethyl acetate (50 mL) and then washed with water (100 mL). The
organic layer was dried (anhydrous Na2SO4) and the solvent
evaporated. The crude residue was purified by flash column
chromatography.
1224, 1084, 986, 903, 828 cmꢂ1
,
dH 5.22 (2H, dd, J ¼ 0.8, 10.9 Hz,
vinyl-H), 5.70 (2H, dd, J ¼ 0.8, 17.6 Hz, vinyl-H), 6.23 (1H, d,
J ¼ 9.9 Hz, vinyl-H), 6.68 (2H, dd, J ¼ 17.6, 10.9 Hz, vinyl-H), 7.19 (1H,
d, J ¼ 8.8 Hz), 7.32 (6H, m, AreH), 7.45 (4H, m, AreH), 7.65 (1H, d,
J ¼ 8.8 Hz), 7.70 (1H, d, J ¼ 8.1 Hz), 7.95 (1H, d, J ¼ 8.4 Hz, 10-H).
Found [M þ H]þ 387.1739; C29H22O requires [M þ H]þ 387.1743.
2.5.2. 3-Phenyl-8-vinyl-3-(4-vinylphenyl)-3H-naphtho[2,1-b]pyran
31
From 8-bromo-3-(4-bromophenyl)-3-phenyl-3H-naphtho[2,1-
b]pyran as off-white microcrystals after elution from silica using
20% toluene in hexane, (0.3 g, 34%), mp ¼ 117.2e118.1 ꢀC, nmax 3062,
1919, 1819, 1630, 1447, 1219, 1092, 1004, 985, 802, 731, 696 cmꢂ1
,
dH
2.4.1. 3-Phenyl-3-(4-vinylphenyl)-3H-naphtho[2,1-b]pyran 26
From 3-(4-bromophenyl)-3-phenyl-3H-naphtho[2,1-b]pyran as
colourless microcrystals after elution from silica using 20% toluene
in hexane, (0.7 g, 76%), mp 97.6e101 ꢀC, nmax 3063, 1853, 1630, 1510,
1
Bis-vinylation employed 2 equivalents of K2CO3 and O’Shea’s reagent and tris-
1222, 1080, 1006, 924, 807, 693, 540 cmꢂ1
,
dH 5.21 (1H, d,
vinylation required 3 equivalents of K2CO3 and O’Shea’s reagent, respectively.