Full Paper
(
(
(
6
7
2
m), 1448 (m), 1316 (m), 1275 (s), 1178 (m), 1155 (m), 938 (s), 920
m), 776 (s), 705 (s), 691 (m), 645 (m), 432 (m) cm . H NMR
pale-orange foamed solid was dehydrated in boiling glacial acetic
acid for 12 h. White pseudorubrene precipitated and was separated
by centrifugation. Washing with acetic acid, ethyl acetate, and hex-
ane and drying in vacuo yielded 7 as a white powder (3.8 g,
–
1 1
3
500 MHz, CDCl , 25 °C, TMS): δ = 7.69 [dd, J(6H,7H) = 7.3 Hz, 4 H,
3
3
-H, 6′-H, 10-H, 10′-H], 7.63 [d, J(3H,2H) = 2.5 Hz, 2 H, 3-H, 3′-H],
3
3
.61 [d, J(2H,3H) = 2.5 Hz, 2 H, 2-H, 2′-H], 7.51 [t, J(8H,7H) = 7.4 Hz,
7.2 mmol; 98 % yield), which was sublimed at 310 °C under high
H, 8-H, 8′-H], 7.37 (t, 4 H, 7-H, 7′-H, 9-H, 9′-H) ppm. 13C NMR vacuum (10 mbar). IR (ATR): ν˜ = 3059 [w, ν(Caryl–H)], 3023 (w),
–3
(500 MHz, CDCl , 25 °C, TMS): δ = 196.65 (C , 2 C, C-4, C-4′), 140.17 1596 (w), 1489 (m), 1461 (m), 1447 (m), 1377 (w), 1351 (w), 1182
3
q
(
C , 2 C, C-1, C-1′), 137.37 (C , 2 C, C-5, C-5′), 133.09 (CH, 2 C, C-8,
(w), 1154 (w), 782 (m), 758 (m), 737 (s), 690 (m), 665 (s), 613 (m),
q
q
–
1
C-8′), 130.47 (CH, 2 C, C-3, C-3′), 129.95 (CH, 4 C, C-6, C-6′, C-10, C- 590 (w), 522 (w), 459 (w) cm . Raman (85 mW): ν˜ = 3059 [w, ν(Caryl-
1
)
0′), 129.78 (CH, 2 C, C-2, C-2′), 128.45 (CH, 4 C, C-7, C-7′, C-9, C-9′
H)], 1596 [s, δ(C–C) ], 1525 (w), 1463 (w), 1382 (w), 1352 (w), 1267
aryl
+
ppm. MS (EI, 70 eV): m/z (%) = 286 (40) [M – H] , 209 (100) [M –
(w), 1174 (w), 1159 (w), 1097 (w), 1059 (w), 994 (w), 925 (w), 300
+
+
+
–1 1
Ph] , 152 (30), 105 (55) [Bz] , 77 (80) [Ph] . C H O (286.33): calcd. (w), 226 (w), 194 (w), 171 (w), 105 (w) cm . H NMR [500 MHz, CS /
C 83.90, H 4.93; found C 83.10, H 4.81.
2
0
14
2
2
CHCl3 (v/v, 400:1), 25 °C]: δ = 8.78 [dd, 3J(11H,12H) = 3.3,
4
3
J(11H,13H) = 3.1 Hz, 2 H, 11-H, 14-H], 8.23 [d, J(10H,9H) = 7.8 Hz,
5
al.,
1
3
,12-Diphenyltetracene-6,11-dione (4): According to Paraskar et
3
3
[44]
2 H, 10-H, 15-H], 8.01 [dd, J(3H,4H) = 3.4, J(3H,5-H) = 2.4 Hz, 2 H,
powdered 1,3-diphenylisobenzofuran (1; 5.0 g, 18.5 mmol,
3
3
3
1
7
2
-H], 7.72 [dd, J(12H,11H) = 3.3, J(12H,14H) = 3.1 Hz, 2 H, 12-H,
3-H], 7.54 [d, J(2H,1H) = 7.4 Hz, 2 H, 2-H, 7-H], 7.40 [t, J(9H,10H) =
.8, J(9H,8H) = 1.2 Hz, 2 H, 9-H, 16-H], 7.28 [dd, J(4H,3H) = 3.4 Hz,
H, 4-H, 5-H], 7.26 [t, J(1H,2H) = 7.6, J(1H,16H) = 1.2 Hz, 2 H, 1-
equiv.) was slowly added to a solution of 1,4-naphthoquinone (2;
.0 g, 19.0 mmol, 1.03 equiv.) in dichloromethane (50 mL) and
3
3
3
3
stirred for 12 h at room temperature. Additional dichloromethane
100 mL) was added and the solution cooled to –78 °C. Dropwise
addition of a BBr solution (30 mL, 1.0 in CH Cl , 30.0 mmol) and
3
3
(
1
3
H, 8-H], 6.68–6.61 (m, 10 H, 17-H–21-H, 22-H–26-H) ppm. C NMR
500 MHz, CS /CHCl (v/v, 400:1), 25 °C]: δ = 151.97 (C , 2 C, C-2a,
M
3
2
2
[
2
3
q
subsequent stirring for an additional 60 min completed the reac-
tion. The darkish solution was heated under reflux for 4 h, cooled
to room temperature and hydrolyzed by pouring on cold water. The
aqueous phase was extracted with dichloromethane after stirring
for 1 h, dried with disodium sulfate, and the solvent removed in
vacuo. In contrast to the procedure of Paraskar et al., the orange
powder was subsequently purified by recrystallization from hot n-
butyl acetate resulting in yellow crystals of high purity (6.8 g,
1
1
C-6a), 146.99 (C , 2 C, C-2b , C-6b ), 141.85 (C ,2 C, C-2c, C-6a),
q
q
1
41.53 (C , 2 C, C-10a, C-14c), 140.61 (C , 2 C, C-21a, C-26a), 135.19
q
q
(
C , 2 C, C-10b, C-14b), 130.46 (C , 2 C, C-10c, C-14a), 127.90 (CH, 4
q
q
C, C-18, C-20, C-23, C-25), 127.56 (CH, 4 C, C-17, C-21, C-22, C-26),
1
3
27.37 (CH, 2 C, C-9, C-15), 126.58 (br., CH, 2 C + 2 C, C-2, C-7 + C-
, C-6), 126.16 (CH, 2 C, C-1, C-8), 126.02 (CH, 2 C, C-12, C-13), 125.93
(CH, 2 C, C-4, C-5), 125.59 (CH, 2 C, C-19, C-24), 125.25 (CH, 2 C, C-
1
6
1, C-14), 122.92 (CH, 2 C, C-10, C-15), 60.88 (C , 2 C, C-2b, C-
q
+
1
6.6 mmol; 90 % yield). IR (ATR): ν˜ = 3057 [w, ν(Caryl–H)], 1677 [s,
b) ppm. MS (EI, 70 eV): m/z (%) = 530 (100) [M] , 453 (40) [M –
ν (C=O)], 1595 (m), 1505 (w), 1586 (w), 1439 (w), 1375 (m), 1367 (m),
s
+
+
Ph] , 376 (30) [M – 2Ph] . C H (530.67): calcd. C 95.06, H 4.94;
42 26
1
9
5
336 (m), 1259 (s), 1069 (w), 1045 (m), 1026 (w), 1001 (w), 991 (m),
64 (w), 795 (w), 773 (m), 737 (m), 722 (m), 697 (s), 671 (w), 641 (w),
found C 95.02, H 4.99.
–
1
96 (m), 506 (w), 450 (w) cm . Raman (85 mW): ν˜ = 3067 [w, ν(Caryl- 5,6:11,12-Di-o-phenylenetetracene (DOPT, 8): Freshly cut potas-
H)], 1671 [m, ν (C=O)], 1600 [m, δ(C–C) ], 1569 (w), 1502 (w), 1375
sium (0.44 g, 11.3 mmol; 6 equiv.) was placed in a flame-dried flask
under argon. The alkali metal was sublimed and deposited in high
s
aryl
(
(
s), 1316 (w), 1255 (m), 1156 (w), 1039 (m), 726 (w), 659 (w), 477
w), 316 (w), 276 (w), 121 (w) cm . H NMR (500 MHz, CDCl , 25 °C, vacuo onto the bottom of the flask. Dried 7 (1.0 g, 1.89 mmol;
–
1 1
3
3
4
TMS): δ = 8.09 [dd, J(7H,8H) = 3.3, J(7H,9H) = 2.5 Hz, 2 H, 7-H, 10-
H], 7.67 [dd, J(8H,7H) = 3.3, J(8H,10H) = 2.5 Hz, 2 H, 8-H, 9-H], 7.63 added. The sealed suspension was vigorously stirred for 1 d at room
1 equiv.) in THF (100 mL) and a pre-dried magnetic stirring bar was
3
4
3
[
t, J(14H,13H) = 6.5 Hz, 4 H, 14-H], 7.57 (t, 2 H, 15-H), 7.59 [dd,
temperature. The end of the reaction was monitored by a color
change from purple to deep-red. Subsequently iPrOH, EtOH, and
water were added in small portions under a flow of argon. Stirring
for 1 h at room temperature led to a blue-black precipitation. The
solid was filtered off, washed with hot iPrOH (*) and water, and
dried with activated molecular sieves (3 Å). The solid was recrystal-
lized from dry toluene to obtain pure 8 (497 mg, 1.32 mmol, 70 %;
overall yield: 62 %). IR (ATR): ν˜ = 3068 [w, ν(Caryl–H)], 1472 (w), 1428
(m), 1382 (w), 1307 (w), 1140 (w), 760 (s, 4H-tetracene), 681 (s, 4H-
3
3
3
J(1H,2H) = 3.3, 4J(1H,3H) = 3.2 Hz, 2 H, 1-H, 4-H], 7.50 [dd,
J(2H,1H) = 3.3, 4J(2H,4H) = 3.2 Hz, 2 H, 2-H, 3-H], 7.34 [dd,
4
13
J(13H,14H) = 6.5, J(13H,15H) = 1.5 Hz, 4 H, 13-H, 16-H] ppm.
C
NMR (500 MHz, CDCl , 25 °C, TMS): δ = 184.36 (C , 2 C, C-6, C-11),
3
q
1
2
1
44.16 (C , 2 C, C-5, C-12), 140.40 (C , 2 C, C-12b, C-5b), 135.76 (C ,
q q q
C, C-4a, C-12a), 133.70 (CH, 2 C, C-8, C-9), 133.13 (C , 2 C, C-6a, C-
q
0a), 128.95 (CH, 2 C, C-15, C-18), 128.94 (CH, 2 C, C-2, C-3), 128.81
(CH, 2 C, C-13, C-16), 128.52 (CH, 4 C, C-14, C-17), 127.74 (C , 2 C,
q
–
1
C-5a, C-11a), 127.24 (CH, 2 C, C-1, C-2), 127.05 (CH, 2 C, C-7, C- phenylene), 460 (w) cm . Raman (85 mW): ν˜ = 3075 [w, ν(Caryl–H)],
+
1
0) ppm. MS (EI, 70 eV): m/z (%) = 409 (30) [M – H] , 286 (70), 209
1682, 1612, 1588 [m, δ(C–C) ], 1448 [s; δ(C–C) ], 1400, 1340,
aryl aryl
+
(100). MS (CI, 70 eV): m/z (%) = 410 (100) [M] . MS (ESI, 70 eV): m/z
1337, 1284, 1170, 1068, 1005 [w, δ[(C–C)aryl], 872, 658, 387, 348,
+
+
–1
(
%) = 411 (100) [M + H] , 433 (20) [M + Na] . C H O (410.47):
178 cm . UV/Vis (CHCl ): λ
= 290, 304, 431, 523, 561, 607 nm.
3
0
18
2
3
max
calcd. C 87.80, H 4.40; found C 87.74, H 4.36.
UV/Vis (CS ): λ
= 427, 533, 574, 622 nm. UV/Vis (THF): λ
= 290,
max
2
max
1
3
2
3
04, 431, 523, 561, 607 nm. H NMR [500 MHz, CS /CDCl (v/v, 40:1),
5 °C, TMS]: δ = 8.43 [dd, J(3H,4H) = 3.6, J(3H,5H) = 3.3 Hz, 4 H,
2 3
5
,12-Diphenyl-5,6:11,12-di-o-phenylene-5,12-dihydrotetracene
Pseudorubrene, 7): Compound 4 (3.0 g, 7.3 mmol; 1 equiv.) was
suspended in dry toluene (300 mL) and heated at 60 °C. An excess
73.1 mL, 20 equiv.) of phenylmagnesium chloride (27 wt.-% in THF,
.0 ) was purged into the clear solution and the reaction mixture
was kept at 80 °C for 48 h. After cooling to room temperature the
green-brown solution was quenched with 1 HCl (150 mL) and
stirred intensely for 1 h. Ice (90 g) and after another 30 min addi-
tional 1
layer was decanted, extracted with water, dried with magnesium DOPT, 9): From the synthesis of DOPT, the purple iPrOH washing
3
4
(
3
4
-H], 7.91 [dd, J(2H,1H) = 3.2, J(15H,1H) = 2.4 Hz, 4 H, 2-H], 7.52
dd, 3J(4H,3H) = 3.6, J(4H,6H) = 3.3 Hz, 4 H, 4-H], 7.17 [dd,
3
[
(
3
3
J(1H,2H) = 3.2, J(1H,15H) = 2.4 Hz, 4 H, 1-H] ppm. HRMS: calcd.
2
M
for C H 376.13; found 376.1252. MS (EI, 70 eV): m/z (%) = 376
30
16
+
2+
(100) [M] , 188 (15) [M] . C H (376.46): calcd. C 95.72, H 4.28;
30 16
M
found C 95.58, H 4.26.
M
HCl (150 mL) was added. The resulting orange organic 5,12-Dihydro-5,6:11,12-di-o-phenylenetetracene
(Dihydro-
sulfate, and solvent was removed under high vacuum at 70 °C. The
solution (*) from the final work-up was separated and dried with
© 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Eur. J. Org. Chem. 2016, 569–578
www.eurjoc.org
577