In Situ Synthesis of Hexakis(alkoxy)diquinoxalino[2,3-a:2′,3′ -c]phenazines: Mesogenic Phase Transition of the Electron-Deficient Discotic Compounds

Article abstract of DOI:10.1021/jo035840l

2,3,8,9,14,15-Hexakis(alkoxy)diquinoxalino[2,3-a:2′,3′- c]phenazines with alkyl side chains varying from 6 to 12 carbon atoms were readily synthesized by the condensation of hexaketocyclohexane with the respective 1,2-bisalkoxy-4,5-diaminobenzene. Polariz

Full text of DOI:10.1021/jo035840l

In Situ Syn th esis of
Hexa k is(a lk oxy)d iqu in oxa lin o[2,3-a :2′,3′-c]p h en a zin es: Mesogen ic
P h a se Tr a n sition of th e Electr on -Deficien t Discotic Com p ou n d s
,
†
†
†
‡
Chi Wi Ong,* Su-Chih Liao, Tsu Hsing Chang, and Hsiu-Fu Hsu
Department of Chemistry, National Sun Yat Sen University, Kaoshiung, Taiwan 804, and Department of
Chemistry, Tamkang University, Tamsui, Taiwan 251
cong@mail.nsysu.edu.tw
Received December 18, 2003
2
,3,8,9,14,15-Hexakis(alkoxy)diquinoxalino[2,3-a:2′,3′-c]phenazines with alkyl side chains varying
from 6 to 12 carbon atoms were readily synthesized by the condensation of hexaketocyclohexane
with the respective 1,2-bisalkoxy-4,5-diaminobenzene. Polarization microscopy and DSC studies
showed all these compounds to exhibit a very wide mesophase range of over 150 °C. An interesting
D
hd to Drd transition was observed for the octyl derivative 3b, as determined by X-ray diffraction
measurements. The hexyl derivative showed three reduction potentials, suggesting that the HATN
core maintained its electron-deficient characteristic and considered suitable as an n-doped discotic-
liquid crystalline material. Incorporation of six alkoxy chains did not override the electron deficiency
of the HATN core.
In tr od u ction
ing has been employed to force self-π-complexation to
exhibit closely spaced dimmers with a one-half ring offset
in the solid phase of hexacarboxamidohexaazatriph-
enylene.14 Reported examples of HAT-based liquid crystal
possess a flexible unfused polyphenyl or succinamide-
polyphenyl16 side chain that has the disadvantage of
introducing excessive conformational freedom, whereby
long-range three-dimensional order may be disrupted.
Hexakis(alkylthio)diquinoxazlino[2,3-a: 2′,3′-c]phena-
zines were reported to exhibit a number of mesophases
Recently, hexaazatriphenylene (HAT) having three
π-deficient pyrazine nuclei at its core has been investi-
gated as a new discogen with the potential to act as
1
5
1
electron carrier. More impressively, intermolecular mul-
tiple hydrogen bonding was utilized to associate a hexaa-
mide-HAT compound for the formation of columnar
mesophases with a record setting disk-to-disk distance
of 3.18 Å that resulted in a high carrier mobility.2
Although acceptor materials with high electron mobility
are in demand, examples of acceptor discogens are
limited.3 This could be due to avoidance of self-π-
complexation of the electron-deficient nature of the cores.
(
two to five) depending on the chain length, but these
1
7
cannot be unambiguously indexed.
We have preliminarily reported the synthesis of the
electron-deficient core of diquinoxazlino[2,3-a:2′,3′-c]-
phenazine (HATN) with six alkoxy chains and found the
Crystal structures of many electron-deficient heterocycles
seem to support this view.4
-13
However, hydrogen bond-
1
8
hexyloxy derivative to exhibit a columnar mesophase.
†
Herein, we report the synthesis, solution electrochemis-
try, and supramolecular assembly of a series of hexakis-
National Sun Yat Sen University.
Tamkang University.
‡
(
1) Uckert, F.; Tak, Y.-H.; Mullen, D.; Bassler, H. Adv. Mater. 2000,
2, 905.
2) Gearba, R. I.; Lehmann, M.; Levin, J .; Ivanov, D. A.; Koch, M.
H.; Barber a´ , J .; Debije, M. G.; Piris, J .; Geerts, Y. H. Adv. Mater. 2003,
5, 1614.
3) (a) Boden, N.; Bushby, R. J .; Headdock, G.; Lozman, O. R.; Wood,
(alkoxy)diquinoxazlino[2,3-a:2′,3′-c]phenazines (3) with
1
longer electron-donating alkoxy side chains. As expected,
the nature of the mesophase and the range of its
mesomorphism are dependent on the side-chain length.
The electrochemical property of 3 has been successfully
carried out for the first time. Interestingly, the electron
(
1
(
A. Liq. Cryst. 2001, 28, 139. (b) Kumar, S.; Rao, D. S. S.; Prasad, S. K.
J . Mater. Chem. 1999, 9, 2751. (c) Boden, N.; Borner, R. C.; Bushby,
R. J .; Clements, J . J . Am. Chem. Soc. 1994, 116, 10807.
(
4) Nishigaki, S.;Yoshioka, H.; Nakatsu, K. Acta Crystallogr., Sect.
B 1978, 34, 875.
(
(12) Phillips, D. C.; Ahmed, F. R.; Barnes, W. H. Acta Crystallogr.
1960, 13, 365.
5) Huiszoon, C. Acta Crystallogr., Sect. B 1976, 32, 998.
(
6) Huiszoon, C.; van der Waal, W. B.; van Egmond, A. B.; Harkema,
(13) Phillips, D. C. Acta Crystallogr. 1956, 9, 237.
S. Acta Crystallogr., Sect. B 1972, 28, 3415.
7) Clearfield, A.; Sims, M. J .; Singh, P. Acta Crystallogr., Sect. B
972, 28, 350.
8) van den Ham, D. M. W.; van Hummel, G. J .; Huiszoon, C. Acta
Crystallogr., Sect. B 1978, 34, 3134.
9) Huiszoon, C.; van Hummel, G. J .; van den Ham, D. M. W. Acta
Crystallogr., Sect. B 1977, 33, 1867.
(14) Beeson, J . C.; Fitzgerald, L. J .; Gallucci, J . C.; Gerkin, R. E.;
Rademacher, J . T.; Czarnik, A. W. J . Am. Chem. Soc. 1994, 116, 4621.
(15) Arikainen, E. O.; Boden, N.; Bushby, R. J .; Lozman, O. R.;
Vinter, J . G.; Wood, A. Angew. Chem., Int. Ed. 2000, 39, 2333.
(16) Pieterse, K.; Van Hal, P. A.; Kleppinger, R.; Vekemans, J . A.
J . M.; J anssen, R. A. J .; Meijer, E. W. Chem. Mater. 2001, 13, 2675.
(17) Kestenont, G.; De Halleux, V.; Lehmann, M.; Ivanov, D. A.;
Watson, M.; Greets, Y. H. J . Chem. Soc., Chem. Commun. 2001, 2074.
(18) Ong, C. W.; Liao, S.-C.; Chang, T. H.; Hsu, H.-F. Tetrahedron
Lett. 2003, 44, 1477.
(
1
(
(
(
(
10) van der Meer, H. Acta Crystallogr., Sect. B 1972, 28, 367.
11) Herbstein, F. H.; Schmidt, G. M. J . Acta Crystallogr. 1955, 8,
3
1
99.
0.1021/jo035840l CCC: $27.50 © 2004 American Chemical Society
Published on Web 04/01/2004
J . Org. Chem. 2004, 69, 3181-3185
3181

Ong et al.
SCHEME 1. Syn th esis of Com p ou n d s 3a -d
TABLE 1. In flu en ce of Alk oxy Ch a in Len gth on th e
Hyd r ogen a tion of 1,2-Bisa lk oxy-4,5-d in itr oben zen e
TABLE 2. Com p a r ison of Tr icon d en sa tion for Wor k u p
a n d in Situ Con d ition
2
a
2b
2c
2d
3a
3b
3c
3d
R
time
C6H13
1 d, ∆ 1 d, ∆ 1 d, ∆
H2, Pd/C (2atm) 6 h
C8H17
C10H21
C12H25
2 d, ∆
R
C6H13
30
75
C8H17
25
68
C10H21
24
65
C12H25
25
60
N2H4, Pd/C
yield (%)
workup
in situ
6 h
60
90
12 h, ∆ 1 d, ∆
61
88
yield (%) N2H4, Pd/C
63
40
90
H2, Pd/C (2atm) 90
silica gel and recrystallization from acetone or ethanol,
and the purity was confirmed using MALDI mass spec-
troscopy and elemental analysis.
deficiency in the HATN core is maintained even with the
introduction of six alkoxy chains, and favorable aromatic
stacking interaction leads to the formation of both
hexagonal and rectangular columnar mesophase.
The liquid crystal properties of 3a -d studied using
polarizing microscopy and differential scanning calori-
metry are summarized in Table 3. For all series 3
compounds, no thermal decomposition was detected on
the basis of reversible heating/cooling cycles. It is also
noted that with longer alkoxy side chains 3b and 3c
suffered severe supercooling; on the other hand, for the
shorter chain analogue 3a , the temperatures and enthal-
pies for melting and crystallization are not much differ-
ent. Previously, we have shown that the side chain length
has to reach six carbon atoms, 3a , for the rectangular
columnar-phase formation assigned by its mosaic texture
and X-ray diffractomogram. In this work, all the com-
pounds exhibited single enantiotropic mesophase except
3b in which two liquid crystal phases were detected.
Compound 3b-d melted from isotropic to give a bire-
fringent fluid phase with large regions of uniform extinc-
tion that is typical of columnar liquid crystal phase. The
ease of homeotropic alignment in these compounds can
be attributed to the large and flat aromatic core and
suggests a low surface tension of the mesophases. An
additional mesophase identifiable by a new texture with
an in-grown needle feature when 3b was further cooled
from the first columnar phase to 174 °C was also
observed, and this fluid phase was maintained until it
crystallized at 61 °C. The clearing temperatures are
found to be chain-length dependent and decrease as the
alkoxy chains lengthened. The small enthalpies of the
columnar to isotropic transition are indicative of disor-
dered mesophases. Surprisingly, compounds 3a -d ex-
hibit a very wide mesophase range of over 150 °C.
All the materials have been investigated by variable-
temperature XRD experiments, and the results are
summarized in Table 4. Only broad halos are observed
at wide angle for all compounds at all mesophases,
Resu lts a n d Discu ssion
As reported, all attempts to synthesize the hexaalkoxy
via nucleophilic substitution of the hexakis(chloro)diqui-
noxazlino[2,3-a:2′,3′-c]phenazine using various alkoxides
afforded the desired 3 in very poor yield along with a
1
8
complex mixture of products. We reported an alterna-
tive synthetic approach to 3 by the direct condensation
of hexaketocyclohexane with 1,2-bisalkoxy-4,5-diami-
nobenzene of different chain lengths to afford the
2
,3,8,9,14,15-hexaalkoxydiquinoxalino[2,3-a: 2′,3′-c]phena-
zines 3a -d , respectively (Scheme 1). The hexaketocyclo-
hexane19 has to be freshly prepared; otherwise, the yield
of the condensation product drops significantly. Reduc-
tion of 1,2-bisalkoxy-4,5-dinitrobenzene to produce 1,2-
bisalkoxy-4,5-diaminobenzene can be achieved using
palladium on charcoal in the presence of hydrazine or
hydrogen. It is noteworthy to point out that the length
of time required for the reduction increases dramatically
with the alkyl chain length due to the poorer solubility
(Table 1). The most common condition used for the
tricondensation reaction involved refluxing in acetic acid,
but we have used ethanol in the presence of a small
amount of acetic acid. This alternative synthetic condition
allows the air-sensitive 1,2-bisalkoxy-4,5-diaminobenzene
obtained from reduction in ethanol to be tricondensed
directly with hexaketocyclohexane, thus avoiding un-
necessary workup (Table 2). The compounds synthesized
were easily purified by chromatographic separation on
(19) Berger, P. J . Am. Chem. Soc. 1942, 64, 67.
3
182 J . Org. Chem., Vol. 69, No. 9, 2004

Synthesis of Hexakis(alkoxy)diquinoxalino[2,3-a:2′,3′-c]phenazines
F IGURE 1. Variable-temperature XRD patterns of 3b.
TABLE 3. P h a se Beh a vior s of 3a -d a
compd
n
phase transitions
3
3
3
3
a
b
c
d
6
97.1 (32.11)
186.6 (5.06)
z K y179.5 (-4.98)z Colrd
229.9 (1.95)
225.6 (-1.78)z I
K y
y
1
2
9
2.1 (-31.59)
8
10
12
114.5 (84.65)
K y61.3 (-36.90)z Colrd
176.0b
224.4 (1.16)
y173.5bz Colhd y221.5 (-1.08)z I
86.0 (76.38)
214.6 (1.41)
K y 0.8 (-56.84)z Colhd y212.5 (-1.28)z I
1
4
94.2 (106.87)
K y52.0 (-2.78)z Colhd
206.1 (2.35)
y206.1 (-1.46)z I
a
-1
The transition temperatures (°C) and enthalpies (in parentheses/kJ mol ) were determined by DSC at 10 °C/min K, crystalline
phase; Colr, rectangular columnar; Colh, hexagonal columnar; I, isotropic. n denotes the length of the alkoxy chains. b Observed by POM
studies but not detected in DSC measurements.
TABLE 4. Va r ia ble-Tem p er a tu r e XRD Da ta for Com p ou n d s 3a -d
compd
mesophase
lattice constant (Å)
obsd (calcd) spacing (Å)
Miller indices
halos obsd (Å)
4.70, 3.58
3
3
a
Colrd at 198 °C
a ) 40.00
b ) 19.15
a ) 25.51
a ) 24.93
a ) 43.68
b ) 22.20
a ) 42.70
b ) 21.76
a ) 27.94
20.00
17.28
22.09
21.59
21.84
19.79
21.35
19.39
24.20
(200)
(110)
(100)
(100)
(200)
(110)
(200)
(110)
(100)
(110)
(100)
(110)
b
Colhd at 207 °C
Colhd at 160 °C
Colrd at 146 °C
4.58, 3.57
4.62, 3.66
4.64, 3.60
Colrd at 128 °C
Colhd at 195 °C
Colhd at 198 °C
4.66, 3.61
4.64, 3.71
4.75, 3.53
3
3
c
1
3.87 (13.97)
25.50
4.68 (14.72)
d
a ) 29.44
1
indicating a disordered liquidlike organization. The XRD
variable-temperature measurements and POM of 3b are
shown in Figures 1 and 2, and two columnar mesophases
are revealed. When cooled from the isotropic melt, a
hexagonal lattice with a dominant (100) reflection in the
small angle region was identified and the d spacing
shrinks with decreasing temperature. Upon further cool-
ing, a rectangular columnar phase that was not detected
by DSC measurements evolves and is assigned based on
the two intense low angle peaks indexed to (110) and
correspond to the estimated intercolumn core-to-core
distance, ca. 24.2, 26.8, and 29.3 Å for 3b, 3c, and 3d ,
respectively, when the cores are center-aligned within
columns and the all-trans alkoxy chains are fully pen-
etrating. The longer intercolumn distance observed could
be attributed to the deviation from the central-aligned
arrangement or less penetration of the side chains. More
importantly, the deviation is chain-length dependent
whereby an almost perfect match was found for 3d .
Therefore, the hydrophobic interactions between the side
chains override the conformational freedom, which dis-
rupts long-range, three-dimensional order for chain
length of up to 12 carbon atoms. No attempt was made
to search for the upper limit of the chain length. The
enforced intracolumnar stacking is also revealed by the
corresponding average core-to-core correlation within
columns observed as broad shoulders of 3.5∼3.7 Å at the
wider angle side of the amorphous halos. These values
are smaller than the 3.7∼4.0 Å reported for the thioether
(200). Hence, for 3b, it appears that the Drd phase slowly
transforms to a Dhd structure. This behavior has not been
observed for the hexaazaphenylene system.
The XRD measurements of 3c and 3d exhibit only the
signal corresponding to a single hexagonal columnar
mesophase. We have observed a crossover from the
discotic rectangular phases (Drd) to discotic hexagonal
phases (Dhd) with increasing side-chain length. The lattice
constants of the compounds with hexagonal phase do not
J . Org. Chem, Vol. 69, No. 9, 2004 3183

Ong et al.
F IGURE 2. POM of 3b.
analogues17 but are significantly larger than 3.18 Å for
hexakis(alkylcarboxamido)hexaazatriphenylene with
strong hydrogen bonds to enforce the intracolumnar
stacking order which resulted in a high carrier-mobility.2
Nevertheless, the increasing core-core attraction of
HATN units while maintaining minimal constrain of the
six alkoxy side chains has encouraged molecular stacking
and led to the formation of a liquid crystalline mesophase.
To determine the ability of 3 to behave as an electron
carrier mesogen, the redox properties of 3 were studied
by cyclic voltammetry (CV), and the greatest drawback
is the insolubility of these compounds in polar solvents.
In dichloromethane using Pt electrodes and at ambient
temperature, 3a showed three reduction waves at -1.25,
Furthermore, 3a -d can be rapidly constructed in a
single step by the condensation of hexaketocyclohexane
with 1,2-bisalkoxy-4,5-diaminobenzene. Future work will
focus on the synthesis of new difunctionalized members
of the family.
Exp er im en ta l Section
Gen er a l P r oced u r e for th e P r ep a r a tion of 1,2-Bis-
a lk oxyben zen e. In a two-neck round-bottom flask (1 L) fitted
with a condenser with a nitrogen inlet containing acetone (500
mL) were added catechol (10 g, 0.09 M) and potassium
carbonate and the mixture stirred at room temperature for 1
h. After this time, the 1-bromoalkane (0.23 M) was added, and
the reaction mixture was refluxed for 2 days. The solid residue
from the reaction mixture was filtered, and the filtrate was
evaporated to dryness. The crude product was then dissolved
in ether and the ether layer washed with water and brine.
-
4 6
1.53, and -1.81 V (conditions: 0.05M Bu NPF in
dichloromethane, 200mV/s, V vs Ag/AgCl) associated,
however, with two corresponding oxidation peaks in the
reverse scanning. The intensity of the second oxidation
peak is approximately twice that of the other peaks,
indicating the coalescence of two oxidation processes into
one. It should be mentioned that attempts to separate
this two-electron oxidation wave into two peaks by
varying the scan rate was not successful. We have
revealed for the first time that the HATN core in 3a can
behave as an electron-acceptor even with the incorpora-
tion of six alkoxy side chains. General speaking, 3a
exhibits similar electron-accepting ability as HAT (-1.42
4
The ether extract was dried over MgSO and evaporated. The
excess 1-bromaoalkane was further removed by distillation
under reduced pressure to give the respective 1,2-bisalkoxy-
benzene.
1,2-Bish exyloxyben zen e: colorless oil (96% yield); 1H
NMR (CDCl
3
, 200 MHz) δ 6.85 (s, 4H), 3.96 (t, 4H, J ) 6.6
Hz), 1.86-1.72 (m, 4H), 1.50-1.30 (m, 12H), 0.89 (t, 6H, J )
+
6
.2 Hz); MS m/z 278 (M , <1), 194 (16), 110 (100), 85 (12).
Anal. Calcd for C18
H, 10.84.
30 2
H O : C, 77.65; H, 10.86. Found: C, 77.44;
1
,2-Bisoctyloxyben zen e: white solid (95% yield); mp 25-
1
2
3
6 °C; H NMR (CDCl , 200 MHz) δ 6.88 (s, 4H), 3.98 (t, 4H,
and -1.72 V in CH
deficient than HAT-hexacarboxytriimide (-0.35 V in
3
CN vs SCE)20 but is less electron
J ) 6.6 Hz), 1.90-1.72 (m, 4H), 1.35-1.20 (m, 20H), 0.88 (t,
+
6H, J ) 6.0 Hz); MS m/z 334 (M , <1), 222 (4), 110 (100). Anal.
1
6
1
CH
3
CN vs SCE). Furthermore, the downfield H NMR
38 2
Calcd for C22H O : C, 78.99; H, 11.45. Found: C, 78.92; H,
1
1.58.
aromatic signals at δ 7.85 of 3a also support the electron-
withdrawing ability of the HATN core.
1
,2-Bisd ecyloxyben zen e: white solid (98% yield); mp 41-
1
4
2 °C; H NMR (CDCl , 200 MHz) δ 6.88 (s, 4H), 3.99 (t, 4H,
3
J ) 6.6 Hz), 1.85-1.74 (m, 4H), 1.46-1.20 (m, 28H), 0.88 (t,
+
Su m m a r y a n d Con clu sion
6H, J ) 6.8 Hz); MS m/z 390 (M , <1) 250 (13), 140 (5), 110
(
46 2
100). Anal. Calcd for C26H O : C, 79.94; H, 11.87. Found:
In conclusion, we have shown that HATN-hexaalkoxy
3) can indeed behave as an electron-deficient liquid
C, 79.94; H, 11.92.
1,2-Bisd od ecyloxyben zen e:21 White solid (95% yield); mp
(
1
4
4
(
7-48 °C; H NMR (CDCl
3
, 200 MHz) δ 6.85 (s, 4H), 3.97 (t,
crystal material. Considering the fact that these com-
pounds contain six electron-donating alkoxy groups, it
is important to determine their ease of accepting elec-
trons. Also for 3, we observe a transition from discotic
rectangular phases to discotic hexagonal phases, and 3b
possesses both phases.
H, J ) 6.0 Hz), 1.83-1.75 (m, 4H), 1.46-1.18 (m, 36H), 0.87
t, 6H, J ) 6.4 Hz); MS m/z 446 (M , <1), 277 (6), 110 (100),
+
7
1 (15).
Gen er a l P r oced u r e for th e P r ep a r a tion of 1,2-Bis-
a lk oxy-4,5-d in itr oben zen e. To a two neck round-bottom
flask containing dichloromethane (50 mL), acetic acid (50 mL),
(
20) Masschelein, A.; Kirsch-De Mesmaeker, A.; Verhoeven, C.;
(21) Antonisse, M. M. G.; Snellink-Ru e¨ l, B. H. M.; Yigit, I.; Eng-
bersen, J . F. J .; Reinhoudt, D. N. J . Org. Chem. 1997, 62, 9034.
Nasielski-Hinkens, R. Inorg. Chim. Acta 1987, 129, L13.
3
184 J . Org. Chem., Vol. 69, No. 9, 2004

Synthesis of Hexakis(alkoxy)diquinoxalino[2,3-a:2′,3′-c]phenazines
and 1,2-bisalkoxybenzene (10 g) cooled to 0 °C was added
slowly 65% nitric acid (30 mL). The reaction was allowed to
warm to room temperature and stirred for a further 1 h. The
mixture was again cooled to 0 °C, 100% nitric acid (15 mL)
was added slowly, the mixture was allowed to warm to room
temperature, and the progress of the reaction was monitored
by TLC. After completion of the reaction, the reaction mixture
was poured into ice-water and the dichloromethane layer
Gen er a l P r oced u r e
for
th e
P r ep a r a tion
of
2,3,8,9,14,15-Hexa k is(a lk oxy)d iqu in oxa lin o-[2,3-a :2′,3′-c]-
p h en a zin es. To a solution of 1,2-bisalkoxy-4,5-diaminoben-
zene (15 mM) and hexaketocyclohexane (4 mM) in ethanol (20
mL) obtained after filtration of the hydrogenation reaction was
added acetic acid (3 mL). The reaction mixture was refluxed
under nitrogen for 24-48 h. Ethanol was then removed and
the residue dissolved in dichloromethane followed by washing
separated. The organic layer was further washed with NaHCO
aq) and brine and dried over MgSO . Removal of the solvent
gave the crude product that was recrystallized from ethanol.
,2-Bish exyloxy-4,5-d in itr oben zen e (1a ): yellow solid
3
-
3
with NaHCO (aq) and brine and drying over MgSO4. Removal
(
4
of the solvent in vacuo gave crude product that has to be
rigorously purified by chromatography separation in silica gel
using dichloromethane as elution and recrystallization from
acetone or ethanol.
1
1
(
76% yield); mp 103-104 °C; H NMR (CDCl , 200 MHz) δ
3
7
1
2
.29 (s, 2H), 4.10 (t, 4H, J ) 6.8 Hz), 1.96-1.79 (m, 4H), 1.52-
2 ,3 ,8 ,9 ,1 4 ,1 5 -H e x a k i s (h e x y l o x y )d i q u i n o x a l i n o -
+
.23 (m, 12H), 0.88 (t, 6H, J ) 6.0 Hz); MS m/z 368 (M , <1),
[2,3-a :2′,3′-c]p h en a zin e (3a ): yellow solid (75% yield); R )
f
84 (5), 200 (12), 184 (28), 135 (20), 85 (100). Anal. Calcd for
0.20 (dichloromethane); H NMR (CDCl , 200 MHz) δ 7.85 (s,
1
3
C
7
18
H
28
O
6
N
2
: C, 58.68; H, 7.66; N, 7.60. Found: C, 58.59; H,
.64; N, 7.60.
,2-Bisoctyloxy-4,5-d in itr oben zen e (1b): yellow solid
6H), 4.30 (t, 12H, J ) 5.6 Hz), 2.07-1.93 (m, 12H), 1.67-1.35
(m, 36H), 0.95 (t, 18H, J ) 6.4 Hz); 13C NMR (CDCl , 125 MHz)
3
1
δ 154.8 (6 × C), 141.6 (6 × C), 141.3 (6 × C), 108.0 (6 × CH),
1
(
(
(
(
63% yield); mp 90-91 °C; H NMR (CDCl3, 200 MHz) δ 7.29
69.8 (6 × CH ), 31.9 (6 × CH ), 29.1 (6 × CH ), 26.0 (6 × CH ),
2
2
2
2
s, 2H), 4.10 (t, 4H, J ) 6.4 Hz), 1.95-1.79 (m, 4H), 1.59-1.22
22.9 (6 × CH ), 14.3 (6 × CH ); MS m/z [MALDI] 985.6 as a
2
3
+
m, 20H), 0.89 (t, 6H, J ) 6.0 Hz); MS m/z 424 (M , <1), 296
2), 200 (2), 184 (9), 111 (14). Anal. Calcd for C22
60 84 6 6
single peak. Anal. Calcd for C H N O : C, 73.14; H, 8.59; N,
H
36
O
6
N
2
: C,
8.53. Found: C, 73.42; H, 8.35; N, 8.11.
,3 ,8 ,9 ,1 4 ,1 5 -H e x a k i s (o c t y l o x y )d i q u i n o x a l i n o -
2,3-a :2′,3′-c]p h en a zin e (3b): yellow solid (68% yield); R
6
2.24; H, 8.55; N, 6.60. Found: C, 62.10; H, 8.63; N, 6.60.
,2-Bisd ecyloxy-4,5-d in itr oben zen e (1c): yellow solid
2
1
[
0
6
f
)
1
(
(
(
(
70% yield); mp 84-85 °C; H NMR (CDCl
3
, 200 MHz) δ 7.29
1
.40 (dichloromethane); H NMR (CDCl
3
, 200 MHz) δ 7.85 (s,
s, 2H), 4.10 (t, 4H, J ) 6.4 Hz), 1.99-1.78 (m, 4H), 1.55-1.21
H), 4.30 (t, 12H, J ) 6.0 Hz), 2.00-1.90 (m, 12H), 1.58-1.41
+
m, 28H), 0.88 (t, 6H, J ) 6.0 Hz); MS m/z 480 (M , <1), 340
3), 200 (3), 184 (6), 111 (11). Anal. Calcd for C26
13
(
3
m, 60H), 0.98 (t, 18H, J ) 6.2 Hz); C NMR (CDCl , 125 MHz)
44 6 2
H O N : C,
δ 154.5 (6 × C), 140.6 (6 × C), 140.4 (6 × C), 107.5 (6 × CH),
6
4.97; H, 9.23; N, 5.83. Found: C, 64.94; H, 9.35; N, 5.86.
,2-Bisd od ecyloxy-4,5-d in itr oben zen e (1d ): yellow solid
6
2
9.8 (6 × CH
9.1 (6 × CH
2
2
), 32.1 (6 × CH
), 26.4 (6 × CH
2
2
), 29.6 (6 × CH
), 23.0 (6 × CH
2
2
), 29.6 (6 × CH
), 14.5 (6 × CH
2
3
),
);
1
1
(
(
(
(
72% yield); mp 81-82 °C; H NMR (CDCl , 200 MHz) δ 7.29
3
MS m/z [MALDI] 1153.9 as a single peak. Anal. Calcd for
s, 2H), 4.10 (t, 4H, J ) 6.4 Hz), 1.95-1.79 (m, 4H), 1.59-1.22
C
9
72
H
108
N
6
O
6
: C, 74.96; H, 9.44; N, 7.28. Found: C, 75.04; H,
.41; N, 7.02.
,3 ,8 ,9 ,1 4 ,1 5 -H e x a k i s (d e c y l o x y )d i q u i n o x a l i n o -
2,3-a :2′,3′-c]p h en a zin e (3c): yellow solid (65% yield); R )
+
m, 36H), 0.89 (t, 6H, J ) 5.6 Hz); MS m/z 536 (M , <1), 184
7), 111 (18), 71 (72). Anal. Calcd for C30
52 6 2
H O N : C, 67.13;
2
H, 9.76; N, 5.22. Found: C, 67.00; H, 9.82; N, 5.15.
[
0
6
f
Gen er a l P r oced u r e for th e P r ep a r a tion of 1,2-Bis-
a lk oxy-4,5-d ia m in oben zen e. Meth od A. In a two-neck flask
containing 1,2-bisalkoxy-4,5-dinitrobenzene (0.01 M) and 10%
Pd on carbon (0.3 g) in ethanol (35 mL) was added hydrazine
monohydrate (0.15 M) slowly, and the reaction mixture was
refluxed for 2 days under nitrogen. The hot reaction solution
1
.5 (dichloromethane); H NMR (CDCl
3
, 200 MHz) δ 7.84 (s,
H), 4.30 (t, 12H, J ) 6.4 Hz), 2.11-1.96 (m, 12H), 1.70-1.17
13
(
3
m, 84H), 0.89 (t, 18H, J ) 6.0 Hz); C NMR (CDCl , 125 MHz)
δ 154.4 (6 × C), 141.6 (6 × C), 140.4 (6 × C), 107.5 (6 × CH),
6
2
2
9.8 (6 × CH
9.7 (6 × CH
2
2
), 32.2 (6 × CH
), 29.6 (6 × CH
2
2
), 29.9 (6 × CH
), 29.1 (6 × CH
2
2
), 29.8 (6 × CH
), 26.3 (6 × CH
2
2
),
),
2
was filtered under N and the filtrate partially evaporated
3.0 (6 × CH
2
), 14.4 (6 × CH
3
); MS m/z [MALDI] 1322.5 as a
under vacuo. On cooling, this gave a white precipitate and was
collected by filtration. The diamine is unstable and has to be
used in situ.
Meth od B. To the 1,2-bisalkoxy-4,5-dinitrobenzene (0.01 M)
in ethanol (20 mL) was added 10% Pd on carbon (0.3 g) and
the mixture hydrogenated in a Parr hydrogenator (8-48 h, 2
atm and maybe heating if necessarily). The solution was
filtered under nitrogen, and the residue was washed with a
further amount of dichloromethane. The product was obtained
single peak. Anal. Calcd for C84
N, 6.36. Found: C, 75.91; H, 10.45; N, 6.02.
,3,8,9,14,15-H e x a k is (d o d e c y lo x y )d iq u in o x a lin o -
2,3-a :2′,3′-c]p h en a zin e (3d ): yellow solid (60% yield); R
132 6 6
H N O : C, 76.32; H, 10.06;
2
[
0
6
(
f
)
1
.40 (dichloromethane); H NMR (CDCl
H), 4.28 (t, 12H, J ) 6.6 Hz), 2.08-1.80 (m, 12H), 1.60-1.40
, 125
MHz) δ 154.3 (6 × C), 140.5 (6 × C), 140.4 (6 × C), 107.5 (6 ×
CH), 69.8 (6 × CH ), 32.2 (6 × CH ), 30.0 (6 × CH ), 29.9 (6 ×
CH ), 29.7 (6 × CH ), 29.7 (6 × CH ), 29.1
), 29.9 (6 × CH
), 26.4 (6 × CH ), 26.0 (6 × CH ), 23.0 (6 × CH ),
4.4 (6 × CH ); MS m/z [MALDI] 1491.2 as a single peak. Anal.
: C, 77.37; H, 10.55; N, 5.64. Found: C,
7.81; H, 10.47; N, 5.94.
3
, 200 MHz) δ 7.86 (s,
m, 108H), 0.98 (t, 18H, J ) 6.0 Hz); 13C NMR (CDCl
3
2
2
2
in the similar manner as above and has to be used in situ.
1
2
2
2
2
1
,2-Bish exyloxy-4,5-d ia m in ob en zen e (2a ): H NMR
(
1
6 × CH
2
2
2
2
(
CDCl
3
, 200 MHz) δ 6.37 (s, 2H), 3.88 (t, 4H, J ) 5.6 Hz), 2.83
3
(b, 4H), 1.82-1.67 (m, 4H), 1.58-1.21 (m, 12H), 0.89 (t, 6H, J
Calcd for C96
156 6 6
H N O
+
)
6.0 Hz); MS m/z 308 (M , <1), 139 (100), 111 (40).
1
7
1
,2-Bisoct yloxy-4,5-d ia m in ob en zen e (2b ):
H NMR
(
CDCl3, 200 MHz) δ 6.38 (s, 2H), 3.86 (t, 4H, J ) 6.6 Hz), 2.85
(
)
b, 4H), 1.82-1.68 (m, 4H), 1.58-1.21 (m, 20H), 0.91 (t, 6H, J
Ack n ow led gm en t. We thank the National Science
Council of Taiwan for financial support of the work and
the Radiation Center for the use of XRD.
+
5.0 Hz); MS m/z 364 (M , <1), 252 (10), 139 (100), 111 (30).
1
1
,2-Bisd ecyloxy-4,5-d ia m in ob en zen e (2c):
CDCl , 200 MHz) δ 6.38 (s, 2H), 3.88 (t, 4H, J ) 5.8 Hz), 2.85
b, 4H), 1.82-1.67 (m, 4H), 1.50-1.12 (m, 28H), 0.88 (t, 6H, J
H NMR
(
(
)
3
Su p p or tin g In for m a tion Ava ila ble: Variable-tempera-
ture XRD patterns and POM of 3c,d , DSC scanning of 3a -d ,
and UV-vis, CV, and IR spectra of 3a . This material is
available free of charge via the Internet at http://pubs.acs.org.
+
6.0 Hz); MS m/z 420 (M , <1) 280 (6), 139 (100).
1
1
,2-Bisd od ecyloxy-4,5-d ia m in oben zen e (2d ): H NMR
CDCl , 200 MHz) δ 6.32 (s, 2H), 3.89 (t, 4H, J ) 6.0 Hz), 2.83
b, 4H), 1.83-1.69 (m, 4H), 1.56-1.22 (m, 36H), 0.89 (t, 6H, J
(
(
)
3
+
5.8 Hz); MS m/z 476 (M , <1), 308 (5), 138 (2), 139 (100).
J O035840L
J . Org. Chem, Vol. 69, No. 9, 2004 3185