Reaction, identification, and fluorescence of aminoperfluorophenazines

Article abstract of DOI:10.1016/j.tet.2008.06.079

Perfluorophenazine regiospecifically reacted with monoalkyl-, dialkyl-, and arylamines to afford the corresponding 2-amino-substituted derivatives. 2-(Ethylamino)- and 2-(diethylamino)perfluorophenazine reacted with another molar amount of ethylamine and

Full text of DOI:10.1016/j.tet.2008.06.079

Tetrahedron 64 (2008) 8830–8836
Contents lists available at ScienceDirect
Tetrahedron
journal homepage: www.elsevier.com/locate/tet
Reaction, identification, and fluorescence of aminoperfluorophenazines
,
a
a
a
a
Masaki Matsui a , Masayuki Suzuki , Izumi Nunome , Yasuhiro Kubota , Kazumasa Funabiki ,
*
Motoo Shiro b, Shinya Matsumoto c, Hisayoshi Shiozaki d
a Department of Materials Science and Technology, Faculty of Engineering, Gifu University, Yanagido, Gifu 501-1193, Japan
b X-ray Research Laboratory, Rigaku Corporation, 3-9-12 Matubara-cho, Akishima, Tokyo 196-8666, Japan
c Department of Environmental Sciences, Faculty of Education and Human Sciences, Yokohama National University, 79-2 Tokiwadai, Hodogaya-ku, Yokohama 240-8501, Japan
d Leather Testing Center, Technology Research Institute of Osaka Prefecture, 1-18-13 Kishibe-naka, Suita, Osaka 564-0002, Japan
a r t i c l e i n f o
a b s t r a c t
Article history:
Received 20 May 2008
Received in revised form 16 June 2008
Accepted 20 June 2008
Available online 25 June 2008
Perfluorophenazine regiospecifically reacted with monoalkyl-, dialkyl-, and arylamines to afford the cor-
responding 2-amino-substituted derivatives. 2-(Ethylamino)- and 2-(diethylamino)perfluorophenazine
reacted with another molar amount of ethylamine and diethylamine to preferentially provide the 2,7-
disubstituted derivatives, respectively. Perfluoro(2,7-dimethylphenazine) was allowed to react with ethyl-
amine to give the 1-ethylamino derivative. These regiospecific reactions were explained by the density
functional theory (DFT) calculations. Perfluorophenazine reacted with ethylenediamine to afford the
2,3-cyclized and N,N0-bis(2-perfluorophenazinyl) derivatives. These amino-substituted products showed
UV–vis absorption (lmax) and fluorescence maxima (Fmax) in the range of 439–536 and 524–613 nm in
hexane, respectively. Some of them exhibit intense fluorescence.
Ó 2008 Published by Elsevier Ltd.
1. Introduction
herein the reaction, identification, and fluorescence properties of
aminoperfluorophenazines.
Phenazines are important compounds due to their application
to dyes and medicine. Fluoro- and perfluorophenazines are syn-
thesized by the chemical1 and electrochemical oxidation2 of fluo-
roanilines. Perfluorophenazine has been reported to react with
a hydroxide ion and dimethylamine to give the 2-hydroxy and 2-
dimethyl-amino derivatives, respectively.3 The photochemical re-
action of perfluorophenazine in aqueous acetonitrile has been
reported to produce the 2-hydroxy derivative.4 However, it was
pointed out that the thermal reaction of perfluorophenazine with
a hydroxide ion might produce the 1-hydroxy derivative.4 As
fluorine atoms on the aromatic ring show complicated fluorine–
fluorine coupling in the 19F NMR spectroscopy, identification of
perfluoroaromatic compounds is difficult. Thus, the reaction of
perfluorophenazine with nucleophiles is not clearly understood.
Therefore, it is of importance to clarify the reaction. Furthermore, as
fluoro-, fluoroalkyl-, perfluoroalkyl-sulfonyl-, and fluoroalkanoyl-
substituted compounds show unique properties, the properties of
fluorine-containing dyes are also of interest from the viewpoint of
their applications.5 Though a few kinds of fluoroalkyl-substituted
dyes such as coumarins and perylenediimides have been reported
to show strong fluorescence, no perfluoroaromatic compounds
showing intense fluorescence have been reported so far. We report
2. Results and discussion
2.1. Reaction and identification
Perfluorophenazine (1) was allowed to react with a molar
amount of amines 2 in the presence of triethylamine (TEA) to
regiospecifically provide the 2-amino-substituted products 3 as
shown in Scheme 1 and Table 1.
F
F
F
F
F
F
N
N
R1
F
F
F
N
F
F
a
2
N
F
F
F
F
F
F
1
3
F
N
N
R1
b
2
7
R2
F
F
F
R1 = alkylNH, dialkylN, arylNH
R2 = EtNH, Et2N
4a 74 % (from 3a)
4d 76 % (from 3d)
Scheme 1. Reaction of 1 with amines 2. Reagents and conditions: (a) 2 (R1H, 1.2 molar
amounts), DMF, TEA, 0–25 ꢀC, 3–24 h. (b) 2 (R2H, 1.2 molar amounts), DMF, TEA,
0–25 ꢀC, 24 h.
* Corresponding author.
E-mail address: matsui@apchem.gifu-u.ac.jp (M. Matsui).
0040-4020/$ – see front matter Ó 2008 Published by Elsevier Ltd.
doi:10.1016/j.tet.2008.06.079

M. Matsui et al. / Tetrahedron 64 (2008) 8830–8836
8831
Table 1
Reaction of 1 with amines 2a
Run
Compd
R1
Time (h)
Yieldb of 3 (%)
1
2
3
4
5
6
7
8
a
b
c
d
e
f
EtNH
c-HexNH
Me2N
Et2N
(CH2)4N
PhNH
3
3
3
3
3
24
24
8
74
92
96
75
91
27
67
85
g
h
4-MeOC6H4NH
4-Et2NC6H4NH
a
A DMF solution (10 mL) of 1 (0.5 mmol) was reacted with amines 2 (0.6 mmol) in
the presence of TEA (0.55 mmol) at 0–25 ꢀC.
b
Isolated yields.
Figure 2. ORTEP drawing of 4d.
The 19F NMR spectrum of 3a, obtained by the reaction of 1 with
ethylamine (2a), showed seven signals at ꢁ157.34 (1F), ꢁ153.47
(1F), ꢁ152.94 (1F), ꢁ151.94 (1F), ꢁ151.16 (1F), ꢁ150.04 (1F), and
ꢁ143.05 (1F) ppm. The EIMS spectrum showed the molecular ion
peak at m/z 349. The elemental analysis data indicated the mo-
lecular formula of C14H6F7N3. It is clear that this compound is
ethylamino-substituted perfluorophenazine. However, these data
are not sufficient to identify whether the product is 1- or 2-ethyl-
amino derivative. Therefore, the X-ray crystallography of 3a, crys-
tallized from a dichloromethane–hexane mixed solution, was
performed. The ORTEP drawing is depicted in Figure 1. It is clear
that only 2-(ethylamino)perfluorophenazine is isolated. The
phenazine ring is planar and the other component atoms are lo-
cated on the same plane.
Perfluoro(2,7-dimethylphenazine) (5) smoothly reacted with
ethylamine (2a) to preferentially give 1-ethylamino derivative 6a in
a 47% yield as shown in Scheme 2. The 19F NMR spectrum of 6a
showed seven signals at ꢁ166.48 (1F), ꢁ150.97 to ꢁ150.89 (1F),
ꢁ136.29 to ꢁ136.14 (1F), ꢁ127.67 to ꢁ127.47 (1F), ꢁ119.87 to
ꢁ119.65 (1F), ꢁ56.12 to ꢁ56.02 (3F), and ꢁ52.40 (3F) ppm. The
EIMS spectrum showed the molecular ion peak at m/z 449. The
elemental analysis showed the component C16H6F11N3. The ORTEP
drawing of 6a is shown in Figure 3. It is clear that the reaction of 5
with 2a gave 1-ethylaminoperfluoro(2,7-dimethylphenazine) (6a).
The phenazine ring is slightly distorted due to steric repulsion
between the neighboring trifluoromethyl and ethylamino groups.
The ethylamino group at the 1-position and trifluoromethyl group
at the 2-position are slightly deviated toward the opposite direction
from the phenazine ring.
F
F
F
F
F
F
NHEt
F
N
N
CF3
F
F
N
N
CF3
F
F3C
F3C
F
5
6a 47 %
Scheme 2. Reaction of 5 with ethylamine (2a). Reagents and conditions: ethylamine
(2a, 1.2 molar amounts), DMF, TEA, 0–25 ꢀC, 1 h.
Figure 1. ORTEP drawing of 3a.
The reaction of 1 with diamines 7a and 7b is shown in Scheme 3.
Compound 1 was allowed to react with ethylenediamine (7a) to
provide both 2,3-cyclized and N,N0-bis(2-perfluorophenazinyl) de-
rivatives 8a and 9a. The EIMS spectrum of 8a revealed the mole-
cular ion peak at m/z 344. The 19F NMR spectrum showed only three
signals at ꢁ163.76 (2F), ꢁ160.91 to ꢁ160.88 (2F), and ꢁ156.45 to
ꢁ156.42 (2F) ppm. The elemental analysis data also supported the
structure. Thus, the compound 8a was identified as the 2,3-cyclized
Compound 1 smoothly reacted with alkylamines 2a, 2b, 2c, 2d,
and 2e to provide 3a, 3b, 3c, 3d, and 3e in good yields, respectively.
When compound 1 was allowed to react with aromatic amines 2f,
2g, and 2h, longer reaction time was required to complete the
reaction due to low nucleophilicity of the aromatic amines. The
yield of 3f was low because of the formation of unidentified
products.
The reaction of 2-ethylamino- and 2-(diethylamino)-
perfluorophenazines 3a and 3d with another molar amount of
amines 2a and 2d preferentially gave the 2,7-diamino derivatives
4a and 4d, respectively, as shown in Scheme 1. The 19F NMR
spectrum of 4d showed three signals at ꢁ154.65 (2F), ꢁ141.62 (2F),
and ꢁ136.01 (2F) ppm. The EIMS spectrum indicated the molecular
ion peak at m/z 430. The elemental analysis data showed the
component C20H20F6N4. Again, it is not clear whether the product is
2,7- or 2,8-disubstituted derivative. Figure 2 shows the ORTEP
drawing of 4d, crystallized from a dichloromethane–hexane mixed
solution. Thus, the product 4d was identified as 2,7-bis(diethyl-
amino)perfluorophenazine. The phenazine ring is planar. The
fluorine and nitrogen atoms are located on the same plane. The
ethyl groups on the amino moieties are projected out of the plane.
The reaction of 3a with 2a also gave 2,7-bis(ethylamino) derivative
4a, whose 19F NMR spectrum was similar to that of 4d.
Figure 3. ORTEP drawing of 6a.

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M. Matsui et al. / Tetrahedron 64 (2008) 8830–8836
F
F
F
at the 1- and 2-positions, TS1 and TS2, respectively, are shown in
F
F
F
F
H
N
Figure 4. The structures were characterized in two ways: (a) the
frequency calculations yielded only one imaginary frequency of
193i and 127i cmꢁ1 for TS1 and TS2 structures, respectively, and (b)
the imaginary frequency vibrational mode for the transition states
clearly showed that the mode leads to the reaction path direction.
The TS2 structure was calculated to be 1.50 kcal molꢁ1 more stable
than TS1 structure, indicating that the activation energy to produce
the 2-substituted derivative is less than that to produce the 1-
substituted product. In the TS1 structure, the phenazine ring was
distorted from planar structure due to steric and/or electronic re-
pulsion between the diethylamino-nitrogen and the nitrogen atom
at the 10-position. TS2 structure could prevent such repulsion by
distorting two fluorine atoms attaching to the 1- and 3-positions.
Hence, it is reasonable that the planar TS2 structure is more stable
than the distorted TS1 structure.
The potential energy profile along the intrinsic reaction co-
ordinate (IRC) of the reaction at the 2-position is shown in Figure 5.
The reaction was exothermic. The potential energy curve showed
a plateau before reaching at TS2. The plateau edge is indicated as
PE2. The structures at PE2 and TS2 together with selected bond
length are shown in Figure 6. The PE2 structure indicates that the
nitrogen atom of 2d is approaching the carbon atom at the
F
F
N
N
F
F
N
N
1
F
F
N
H
F
8a 29 %
F
F
F
F
F
F
F
H
N
H
N
N
F
F
F
F
N
N
+
n
F
N
F
F
9a (n = 2) 21 %
9b (n = 4) 22 %
Scheme 3. Reaction of 1 with diamines 7a and 7b. Reagents and conditions: ethyl-
enediamine (7a, n¼2, 1.2 molar amounts), DMF, TEA, 0–25 ꢀC, 1.5 h, and 1,4-di-
aminobutane (7b, n¼4, 1.2 molar amounts), DMF, 0–25 ꢀC, 3 h.
derivative. The EIMS spectrum of 9a showed the molecular ion peak
at m/z 668. The 19F NMR spectrum of 9a showed seven signals at
ꢁ156.95 (2F), ꢁ156.82 (2F), ꢁ156.74 to ꢁ156.66 (2F), ꢁ155.04 (2F),
ꢁ154.37 (2F), ꢁ154.13 (2F), and ꢁ143.01 (2F) ppm. The reaction of 1
with butane-1,4-diamine (7b) afforded only N,N0-bis(2-per-
fluorophenazinyl) derivative 9b.
2.2. DFT calculations for regiospecific reactions
To elucidate the regiospecific substitution reactions of per-
fluorophenazines with amines, the DFT calculations were per-
formed with the Gaussian 03W program.6 The structures were
optimized at the B3LYP/6-31G
zero-point energy corrections, which were scaled by a factor of
0.9804.10 The calculated partial charge and fukui function (f
),
*
level.7–9 All the energies include the
*
which did not reproduce the reaction, and cartesian coordinates of
the optimized structures are shown in Supplementary data.
Firstly, the reaction of 1 with amines 2 to produce the 2-amino
derivatives 3 was examined. The reaction of 1 with 2d was in-
vestigated in detail. The geometries of 1, 2d, transition-state
structures, (diethylamino)perfluoro-phenazines, and hydrogen
fluoride were optimized. The optimized transition-state structures
Figure 5. Calculated potential energy profile along the intrinsic coordination for re-
action of 1 with 2d at 2-position.
Figure 4. Optimized transition-state structures TS1 and TS2 leading to 1- and 2-diethylamino derivatives in reaction of 1 with 2d.

M. Matsui et al. / Tetrahedron 64 (2008) 8830–8836
8833
Figure 6. SH2 and TS2 structures and selected bond length (Å).
2-position of 1. The TS2 structure depicts that the C–N linkage is
formed at the 2-position and, at the same time, hydrogen fluoride is
eliminating. Thus, the regiospecific substitution reaction of 1 with
amines 2 proceeds by way of four-centered transition state to
produce the 2-amino derivatives 3.
Figure 8. Optimized transition-state structures TS271, TS273, and TS274 leading to
1-, 3-, and 4-ethylamino derivatives in the reaction of 5 with 2a.
Next, the reaction of 3d with 2d to form 2,7-bis(diethylamino)
derivative 4d was examined. The calculated transition-state struc-
tures, TS26, TS27, TS28, and TS29 are shown in Figure 7. The TS27
structure was calculated to be most stable followed by TS28, TS26,
and TS29 structures. This result supports that 2-amino-
perfluorophenazines 3 regiospecifically react with amines 2 to give
the 2,7-disubstituted products 4.
Finally, the regiospecific reaction of 5 with ethylamine (2a) to
produce the 1-ethylamino derivative 6a was examined. TS271
structure was calculated to be most stable followed by TS274 and
TS273 structures as shown in Figure 8. This result clearly shows that
the substitution reaction of 5 with 2a regiospecifically proceeds at
the 1-position.
1.5
1.0
0.5
0
1000
800
Hexane
UV-vis
FL
Ethanol
Dichloromethane
Toluene
600
Hexane
Toluene
Dichloro- 400
methane
200
2.3. UV–vis absorption and fluorescence spectra
Ethanol
0
300
400
500
Wavelength / nm
600
700
The UV–vis absorption and fluorescence spectra of 3a in various
solvents are shown in Figure 9. Compound 3a showed positive sol-
vatochromism as normally observed for non-ionic dyes. The dipole
moment of 3a in the ground and excited states were calculated to be
5.32 and 9.19 D, respectively, supporting its positive
Figure 9. UV–vis absorption and fluorescence spectra of 3a in various solvents. Solid
and dotted lines represent UV–vis absorption and fluorescence spectra, respectively.
Measured at the concentration of 1ꢂ10ꢁ4 mol dmꢁ3 at 25 ꢀC.
Figure 7. Optimized transition-state structures TS26, TS27, TS28, and TS29 leading to 2,6-, 2,7-, 2,8-, and 2,9-bis(diethylamino) derivatives in the reaction of 3d with 2d.

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M. Matsui et al. / Tetrahedron 64 (2008) 8830–8836
1.5
1.0
0.5
0
1000
800
600
400
200
0
The UV–vis absorption and fluorescence spectra of selected
3a
phenazine (1')
phenazine derivatives are indicated in Figures 10 and 11. Their
spectral data are listed in Table 2. The lmax of phenazines 10 and 1
were observed at 362 and 367 nm in hexane, respectively, there
being no remarkable difference between the fluorine-free and
FL
UV-vis
4a
4a
3a
perfluoro derivatives. The molar absorption coefficient (3
) of 10
(15,200) was larger than that of 1 (7460). The lmax of 2-amino de-
rivatives 3a–h (456–509 nm) were more bathochromic than 1
(367 nm). 2,7-Disubstituted derivatives 4a and 4d (439 and
476 nm, respectively) were more bathochromic than 1 (362 nm). 1-
Ethylamino derivative 6a (536 nm) was more bathochromic than 5
(414 nm). The lmax of 8a, 9a, and 9b were observed at 441, 465, and
473 nm in dichloromethane, respectively. Thus, the introduction of
alkylamino and arylamino group(s) into perfluorophenazines
caused bathochromic shift. The lmax of 3h in ethanol shifted
from 550 to 468 nm by addition of a drop of diluted hydro-
chloric acid. These results indicate that the 2-amino-substituted
perfluorophenazines have intramolecular charge-transfer chro-
mophoric system from the amino substituent(s) to pyrazine
moiety.
No fluorescence was observed for fluorine-free 10. Non-amino-
substituted perfluorophenazines 1 and 5 showed weak fluores-
cence. Interestingly, amino-substituted perfluorophenazines 3a,
3b, 3c, 3d, 3e, 3f, 4a, 4d, 8a, 9a, and 9b were fluorescent com-
pounds, showing Fmax in the range of 524–583 nm. In a series of 2-
(4-substituted anilino) derivatives 3f, 3g, and 3h, the fluorescence
intensity decreased with increasing electron-donating ability of the
substituent at the 4-position. This result is opposite to the known
information that fluorescence intensity increases by introducing
electron-donating substituents. N,N0-Bis[perfluoro(2-phenazinyl)]
derivatives 9a and 9b were less fluorescent than alkylamino de-
rivatives 3a, 3b, 3c, 3d, and 3e. Though no fluorescence was ob-
served for 3h and 6a, compounds 3a, 3b, 3c, 3d, 3e, 3f, and 4d were
1
1
300
400
500
Wavelength / nm
600
700
Figure 10. UV–vis absorption and fluorescence spectra of 1, 10, 3a, and 4a in hexane.
Solid and dotted lines represent UV–vis absorption and fluorescence spectra, re-
spectively. Measured at the concentration of 1ꢂ10ꢁ4 mol dmꢁ3 at 25 ꢀC.
solvatochromism. The Fmax of 3a also showed positive sol-
vatochromism. The fluorescence intensity drastically decreased in
polar solvents.
1000
1.5
8a
3a
FL
9a
UV-vis
800
600
400
200
0
1.0
3a
0.5
0
9a
5
6a
intensely fluorescent compounds (Ff>0.88). No such intensely
fluorescent perfluoroaromatic compounds have been reported so
far. These new materials have potential applications for emitters in
OLED and solid-state organic dye laser.
5
8a
300
400
500
Wavelength / nm
600
700
3. Conclusions
Figure 11. UV–vis absorption and fluorescence spectra of 3a, 5, 6a, 8a, and 9a. Solid
and dotted lines represent UV–vis absorption and fluorescence spectra, respectively.
Compounds 3a, 5, and 6a were measured in hexane at the concentration of
1ꢂ10ꢁ4 mol dmꢁ3 at 25 ꢀC. Compounds 8a and 9a were measured in dichloromethane
at the concentration of 1ꢂ10ꢁ4 mol dmꢁ3 at 25 ꢀC.
Some novel aminoperfluorophenazines were synthesized and
identified by X-ray crystallography. The regiospecific reactions of
perfluorophenazines with amines were elucidated by DFT
Table 2
UV–vis absorption and fluorescence spectra of phenazines
R1
R2
lmax (nm)
3
Fmaxa (nm)
Ffb
a
Run
Compd
1
2
3
4
5
6
7
8
10
1
d
362
367
456
460
467
470
491
460
479
509
439
476
414
15,200
7460
7070
7200
7000
7230
8000
8100
7700
7400
8800
10,400
3360
3000
13,300
12,300
14,400
dc
dc
F
F
F
F
F
F
F
F
F
466
524
545
546
551
560
537
613
dc
0.06
3a
3b
3c
3d
3e
3f
3g
3h
4a
4d
5
EtNH
c-HexNH
Me2N
Et2N
(CH2)4N
C6H5NH
4-MeOC6H4NH
4-Et2NC6H4NH
EtNH
Et2N
CF3
d
0.94
0.92
0.97
0.98
0.88
0.97
<0.01
dc
9
10
11
12
13
14
15
16
17
F
EtNH
Et2N
CF3
d
d
d
d
560
559
465
dc
583d
579d
583d
0.47
0.92
0.09
dc
0.04d
0.33d
0.26d
6a
8a
9a
9b
536
441d
465d
473d
d
d
d
a
b
c
Measured in hexane at the concentration of 1ꢂ10ꢁ4 mol dmꢁ3 at 25 ꢀC otherwise cited.
Determined using quinine sulfate in 0.1 mol dmꢁ3 of sulfuric acid (Ff¼0.55, lex¼366 nm).
No fluorescence.
d
Measured in dichloromethane at the concentration of 1ꢂ10ꢁ4 mol dmꢁ3 at 25 ꢀC.

M. Matsui et al. / Tetrahedron 64 (2008) 8830–8836
8835
calculations. Perfluorophenazine reacted with ethylenediamine to
provide 2,3-cyclized and N,N0-bis(2-phenazinyl) derivatives. The
amino-substituted products were fluorescent compounds, the Fmax
being in the range of 524–613 nm. Some of the products were in-
tensely fluorescent compounds showing Ff higher than 0.88. This is
the first report that perfluoroaromatic compounds show highly
intense fluorescence.
16.3 Hz, 1F), ꢁ74.78 (t, J¼16.3 Hz, 1F), ꢁ74.25 (t, J¼16.3 Hz, 1F),
ꢁ73.08 (t, J¼16.3 Hz, 1F), ꢁ68.83 (br s, 1F), ꢁ57.02 (br s, 1F); EIMS
(70 eV) m/z (rel intensity) 349 (Mþ; 100), 348 (80), 333 (26), 306
(32), 174 (25). Anal. Calcd for C16H6F7N3: C, 48.15; H, 1.73; N, 12.03%.
Found: C, 47.93; H, 1.76; N, 11.91%.
4.3.4. 2-Diethylamino-1,3,4,6,7,8,9-heptafluorophenazine (3d)
Mp 132.0–132.5 ꢀC; 1H NMR (CDCl3)
d
¼1.26 (t, J¼7.1 Hz, 6H),
4. Experimental
4.1. Instruments
3.54 (q, J¼7.1 Hz, 4H); 19F NMR (CDCl3, ext. CF3CO2H)
¼ꢁ75.88 (t,
d
J¼14.9 Hz, 1F), ꢁ74.00 (t, J¼14.9 Hz, 1F), ꢁ73.86 (t, J¼15.8 Hz, 1F),
ꢁ73.48 (t, J¼15.8 Hz, 1F), ꢁ72.39 (t, J¼15.8 Hz, 1F), ꢁ65.52 (d,
J¼15.8 Hz, 1F), ꢁ56.00 (d, J¼14.9 Hz, 1F); EIMS (70 eV) m/z (rel in-
tensity) 377 (Mþ; 39), 362 (100), 334 (71). Anal. Calcd for
Melting points were measured with a Yanagimoto MP-S2 micro-
melting-point apparatus. NMR spectra were recorded on JEOL
ECA500 and Varian Inova 400 and 500 spectrometers. Mass spectra
were taken on a Shimadzu QP-1000 spectrometer. UV–vis absorp-
tion and fluorescence spectra were measured with Shimadzu
UV-160A and Hitachi F-4500 spectrometers, respectively. Elemen-
tal analysis was performed with a Yanaco MT-6 CHN corder.
C16H10F7N3: C, 50.93; H, 2.67; N, 11.14%. Found: C, 50.98; H, 2.62;
N, 11.15%.
4.3.5. 1,3,4,6,7,8,9-Heptafluoro-2-pyrrolidinophenazine (3e)
Mp 278.5–279.0 ꢀC; 1H NMR (CDCl3)
d
¼2.04–2.07 (m, 4H),
3.93–3.97 (m, 4H); 19F NMR (CDCl3, ext. CFCl3)
d
¼ꢁ155.72 (t,
J¼16.6 Hz, 1F), ꢁ153.65 (t, J¼14.0 Hz, 1F), ꢁ152.31 (t, J¼16.6 Hz, 1F),
ꢁ151.59 (br s, 1F), ꢁ151.48 (t, J¼16.6 Hz, 1F), ꢁ150.63 (t, J¼16.6 Hz,
1F), ꢁ133.89 (br s, 1F); EIMS (70 eV) m/z (rel intensity) 375 (Mþ;
100), 374 (80), 332 (32), 319 (49), 305 (23). Anal. Calcd for
4.2. Materials
Ethylamine (2a), dimethylamine (2c), diethylamine (2d), 4-
methoxyaniline (2g), and butane-1,4-diamine (7b) were purchased
from Nakarai Tesque Co., Ltd. Phenazine (10), cyclohexylamine (2b),
pyrrolidine (2e), aniline (2f), N,N-diethyl-p-phenylenediamine
(2h), and ethylenediamine (7a) were purchased from Tokyo Kasei
Co., Ltd. Perfluorophenazine (1) and perfluoro(2,7-dimethylphe-
nazine) (5) were prepared as described in the literature.11
C16H8F7N3: C, 51.21; H, 2.15; N, 11.20%. Found: C, 51.23; H, 2.42; N,
11.19%.
4.3.6. 2-Anilino-1,3,4,6,7,8,9-heptafluorophenazine (3f)
Mp 207.0–208.0 ꢀC; 1H NMR (CDCl3)
d
¼6.44 (br s, 1H), 7.14–7.20
(m, 3H), 7.35–7.39 (m, 2H); 19F NMR (CDCl3, ext. CF3CO2H)
d
¼ꢁ76.25 (t, J¼15.9 Hz, 1F), ꢁ75.08 (t, J¼15.9 Hz, 1F), ꢁ74.74 (t,
4.3. Reaction of phenazines with amines
J¼15.9 Hz, 1F), ꢁ74.65 (t, J¼15.9 Hz, 1F), ꢁ73.06 (t, J¼15.9 Hz, 1F),
ꢁ64.46 (d, J¼15.9 Hz, 1F), ꢁ62.21 (d, J¼15.9 Hz, 1F); EIMS (70 eV)
m/z (rel intensity) 397 (Mþ; 100), 378 (65), 377 (94). Anal. Calcd for
To a DMF solution (10 mL) of phenazines 1, 3, or 5 (0.5 mmol)
and triethylamine (0.55 mmol) was added an amine 2 or 7
(0.6 mmol). Then, the mixture was stirred. After the reaction was
completed, the reaction mixture was poured into water (100 mL).
The product was extracted with ethyl acetate, purified by column
chromatography (SiO2, 3a, 3b, 3c, 3d, 3e, 3f, 3g, 3h, and 9b: chlo-
roform; 4a, and 4d, and 6a: toluene; 8a and 9a: chloroform–ethyl
acetate¼1:1), and recrystallized (3a and 4d: hexane; 3b, 3c, 3d, 3e,
3f, 3g, 3h, 4a, 6a, 8a, 9a, and 9b: benzene). The physical and spectral
data are shown below.
C
18H6F7N4: C, 54.42; H, 1.52; N, 10.58%. Found: C, 54.24; H, 1.60; N,
10.34%.
4.3.7. 1,3,4,6,7,8,9-Heptafluoro-2-(4-methoxyanilino)-
phenazine (3g)
Mp 195.0–196.0 ꢀC; 1H NMR (CDCl3)
d
¼3.84 (s, 3H), 6.36 (br,1H),
6.92 (d, J¼9.7 Hz, 2H), 7.16 (d, J¼9.7 Hz, 2H); 19F NMR (CDCl3, ext.
CF3CO2H)
d¼ꢁ74.83 (t, J¼15.3 Hz, 1F), ꢁ73.73 (t, J¼16.6 Hz, 1F),
ꢁ73.63 (t, J¼16.6 Hz, 1F), ꢁ73.09 (t, J¼16.6 Hz, 1F), ꢁ71.63 (t, J¼
16.6 Hz, 1F), ꢁ66.68 (d, J¼15.3 Hz, 1F), ꢁ61.69 (d, J¼15.3 Hz, 1F);
EIMS (70 eV) m/z (rel intensity) 427 (Mþ; 100), 412 (75), 364 (18),
344 (27). Anal. Calcd for C19H4F7N3O: C, 53.41; H, 1.89; N, 9.83%.
Found: C, 53.34; H, 2.13; N, 9.80%.
4.3.1. 2-Ethylamino-1,3,4,6,7,8,9-heptafluorophenazine (3a)
Mp 143.0–143.5 ꢀC; 1H NMR (CDCl3)
d
¼1.41 (t, J¼7.1 Hz, 3H),
3.79 (quin d, J¼7.1 and 3.8 Hz, 2H), 4.63 (br s, 1H); 19F NMR (CDCl3,
ext. CFCl3)
d¼ꢁ157.34 (d, J¼14.4 Hz, 1F), ꢁ153.47 (t, J¼14.4 Hz, 1F),
ꢁ152.94 (t, J¼16.4 Hz, 1F), ꢁ151.94 (t, J¼16.4 Hz, 1F), ꢁ151.16 (t,
J¼16.4 Hz,1F), ꢁ150.04 (t, J¼16.4 Hz,1F), ꢁ143.05 (d, J¼14.4 Hz,1F);
EIMS (70 eV) m/z (rel intensity) 349 (Mþ; 44), 334 (100). Anal. Calcd
for C14H6F7N3: C, 48.15; H, 1.73; N, 12.03%. Found: C, 47.76; H, 1.92;
N, 12.02%.
4.3.8. 2-[4-(Diethylamino)anilino]-1,3,4,6,7,8,9-
heptafluorophenazine (3h)
Mp 171.0–171.5 ꢀC; 1H NMR (CDCl3)
d
¼1.18 (t, J¼7.3 Hz, 6H), 3.37
(q, J¼7.3 Hz, 4H), 6.32 (br, 1H), 6.66 (d, J¼8.3 Hz, 2H), 7.10 (d,
J¼8.3 Hz, 2H); 19F NMR (CDCl3, ext. CFCl3)
¼ꢁ153.08 to ꢁ153.02
d
(m, 1F), ꢁ152.45 to ꢁ152.38 (m, 1F), ꢁ151.69 to ꢁ151.61 (m, 1F),
ꢁ151.10 to ꢁ151.02 (m, 1F), ꢁ149.97 to ꢁ149.90 (m, 1F), ꢁ146.72 to
ꢁ146.64 (m, 1F), ꢁ139.68 to ꢁ139.60 (m, 1F); EIMS (70 eV) m/z (rel
intensity) 468 (Mþ; 76), 453 (100), 424 (23), 377 (23), 376 (20).
Anal. Calcd for C22H15F7N4: C, 56.42; H, 3.23; N, 11.96%. Found: C,
56.29; H, 3.23; N, 11.91%.
4.3.2. 2-Cyclohexylamino-1,3,4,6,7,8,9-heptafluorophenazine (3b)
Mp 129.0–130.0 ꢀC; 1H NMR (CDCl3)
d
¼1.23–1.84 (m, 8H), 2.20
(d, J¼9.2 Hz, 2H), 3.97 (br s, 1H), 4.55 (s, 1H); 19F NMR (CDCl3, ext.
CFCl3)
d¼ꢁ156.26 (d, J¼13.5 Hz, 1F), ꢁ153.42 (t, J¼13.5 Hz, 1F),
ꢁ153.13 (t, J¼16.7 Hz, 1F), ꢁ152.04 (t, J¼16.7 Hz, 1F), ꢁ151.20
(t, J¼16.7 Hz, 1F), ꢁ150.15 (t, J¼16.7 Hz, 1F), ꢁ142.80 (d, J¼13.5 Hz,
1F); EIMS (70 eV) m/z (rel intensity) 403 (Mþ; 51), 360 (23), 340
(25), 321 (100). Anal. Calcd for C18H12F7N3: C, 53.61; H, 3.00; N,
10.42%. Found: C, 53.41; H, 2.96; N, 10.24%.
4.3.9. 2,7-Bis(ethylamino)-1,3,4,6,8,9-hexafluorophenazine (4a)
Mp 159.5–160.0 ꢀC; 1H NMR (CDCl3)
d
¼1.34 (t, J¼7.1 Hz, 6H),
3.51 (br, 4H), 4.39 (br, 2H); 19F NMR (CDCl3, ext. CFCl3)
d
¼ꢁ154.02
to ꢁ153.98 (m, 2F), ꢁ153.60 (br s, 2F), ꢁ152.62 to ꢁ152.59 (m, 2F);
EIMS (70 eV) m/z (rel intensity) 374 (Mþ; 86), 359 (58), 329 (100).
Anal. Calcd for C16H12F6N4: C, 51.34; H, 3.23; N, 14.97%. Found: C,
51.55; H, 3.61; N, 15.07%.
4.3.3. 2-Dimethylamino-1,3,4,6,7,8,9-heptafluorophenazine (3c)
Mp 152.0–153.0 ꢀC; 1H NMR (CDCl3)
d
¼3.26 (s, 6H); 19F NMR
(CDCl3, ext. CF3CO2H)
d
¼ꢁ76.62 (t, J¼13.8 Hz, 1F), ꢁ74.83 (t, J¼

8836
M. Matsui et al. / Tetrahedron 64 (2008) 8830–8836
4.3.10. 2,7-Bis(diethylamino)-1,3,4,6,8,9-hexafluorophenazine (4d)
C
16H6F11N3, Mw¼449.23, monoclinic, P21/c, Z¼4, a¼10.6161(8),
Mp 190.5–191.0 ꢀC; 1H NMR (CDCl3)
d
¼1.21 (t, J¼7.2 Hz, 6H),
b¼12.2022(9), c¼13.328(1) Å,
b
¼111.433(5)ꢀ, Dcalcd¼1.853 g/cm3,
3.47 (q, J¼7.2 Hz, 4H); 19F NMR (CDCl3, ext. CFCl3)
d
¼ꢁ154.65 (t,
15,540 reflections were collected, 2893 unique (Rint¼0.080), 2093
J¼15.5 Hz, 2F), ꢁ141.62 (d, J¼15.5 Hz, 2F), ꢁ136.01 (d, J¼15.5 Hz,
2F); EIMS (70 eV) m/z (rel intensity) 430 (Mþ; 38), 415 (100), 371
(22), 343 (24). Anal. Calcd for C20H20F6N4: C, 55.81; H, 4.68; N,
13.02%. Found: C, 55.74; H, 4.71; N, 12.95%.
observed (I>2
s(I)), 275 parameters, R1¼0.0455, wR2¼0.1298,
GOF¼0.994, refinement on F2. The measurement was performed on
a Rigaku Raxis-RAPID imaging plate diffractometer with a graphite-
monochromated Cu K
a maximum 2
a maximum 2
a radiation. The data were collected to
q
value of 136.5ꢀ at room temperature for 3a and to
value of 136.4ꢀ at ꢁ180(1) ꢀC under cold N2 gas flow
4.3.11. 1-Ethylamino-3,4,6,8,9-pentafluoro-2,7-bis(trifluoromethyl)-
q
phenazine (6a)
for 4d and 6a. 24, 30, and 26 (D4¼30ꢀ) images were measured
using an oscillation technique for 3a, 4d, and 6a, respectively. An
absorption correction was applied for 4d and 6a, but not applied for
Mp 110.5–111.0 ꢀC; 1H NMR (CDCl3)
d
¼1.43 (t, J¼7.1 Hz, 3H),
3.63–3.67 (m, 2H), 6.87 (br s, 1H); 19F NMR (CDCl3, ext. CFCl3)
d
¼ꢁ166.48 (d, J¼17.1 Hz, 1F), ꢁ150.97 to ꢁ150.89 (m, 1F), ꢁ136.29
3a. The structures were solved by the direct method (SHELX9712
)
to ꢁ136.14 (m, 1F), ꢁ127.67 to ꢁ127.47 (m, 1F), ꢁ119.87 to ꢁ119.65
(m, 1F), ꢁ56.12 to ꢁ56.02 (m, 3F), ꢁ52.40 (s, 3F); EIMS (70 eV) m/z
(rel intensity) 449 (Mþ; 92), 434 (34), 430 (31), 429 (50), 414 (100),
408 (35), 388 (34), 387 (29). Anal. Calcd for C16H6F11N3: C, 42.78; H,
1.35; N, 9.35%. Found: C, 43.78; H, 1.72; N, 9.39%.
and refined by least-squares calculations using the Crystal Structure
program package.13 All non-hydrogen atoms for these compounds
were refined anisotropically. The hydrogen atoms for 3a and 4d
were located on the calculated positions and not refined. For 6a, the
hydrogen atom of the amino group was found in the difference
Fourier map and only the positional parameters were refined. The
other hydrogen atoms were located on the calculated positions and
not refined.
Crystallographic data have been deposited at the CCDC,12 Union
Road, Cambridge CB2 1EZ, UK and copies can be obtained on re-
quest, free of charge, by quoting the publication citation and the
deposition numbers for 3a (CCDC297182), 4d (CCDC297183), and
6a (CCDC297184), respectively.
4.3.12. Pyridazino[2,3-b]-1,2,3,4,6,11-hexafluorophenazine (8a)
Mp>300 ꢀC; 1H NMR (acetone-d6)
d
¼3.71 (br s, 2H), 6.94 (s, 4H);
19F NMR (acetone-d6, ext. CFCl3)
d
¼ꢁ163.76 (s, 2F), ꢁ160.91 to
ꢁ160.88 (m, 2F), ꢁ156.45 to ꢁ156.42 (m, 2F); EIMS (70 eV) m/z (rel
intensity) 344 (Mþ; 93), 343 (100), 328 (26), 207 (35). Anal. Calcd
for C14H6F6N4: C, 48.85; H, 1.76; N, 16.28%. Found: C, 48.61; H, 2.10;
N, 15.98%.
4.3.13 . N,N0-Bis(1,3,4,6,7,8,9-heptafluoro-2-phenazinyl)-ethane-
Supplementary data
1,2-diamine (9a)
Mp 297.0–297.5 ꢀC (dec); 1H NMR (acetone-d6)
d
¼2.78 (s, 4H),
The calculated partial charge, fukui function (f ), and the carte-
*
4.17 (br s, 2H); 19F NMR (acetone-d6, ext. CFCl3)
d¼ꢁ156.95 (t, J¼
sian coordinates of the optimized structures are provided. Sup-
plementary data associated with this article can be found in the
online version, at doi:10.1016/j.tet.2008.06.079.
16.5 Hz, 2F), ꢁ156.82 (br, 2F), ꢁ156.74 to ꢁ156.66 (m 2F), ꢁ155.04
(t, J¼16.5 Hz, 2F), ꢁ154.37 (t, J¼16.5 Hz, 2F), ꢁ154.13 (t, J¼16.5 Hz,
2F), ꢁ143.01 (br s, 2F); EIMS (70 eV) m/z (rel intensity) 668 (Mþ;
20), 335 (100), 334 (95). Anal. Calcd for C26H6F14N6: C, 46.72; H,
0.90; N, 12.57%. Found: C, 46.97; H, 0.69; N, 12.61%.
References and notes
1. Leyva, E.; Monreal, E.; Medina, C.; Leyva, S. Tetrahedron Lett. 1997, 38,
7847–7848.
2. (a) Hudson, A. G.; Pedler, A. E.; Tatlow, J. C. Tetrahedron 1970, 26, 3791–3797; (b)
Hudson, A. G.; Pedler, A. E.; Tatlow, J. C. Tetrahedron Lett. 1968, 17, 2143–2146.
3. Hudson, A. G.; Jenkins, M. L.; Pedler, A. E.; Tatlow, J. C. Tetrahedron 1970, 26,
5781–5787.
4.3.14 . N,N0-Bis(1,3,4,6,7,8,9-heptafluoro-2-phenazinyl)-butane-
1,4-diamine (9b)
Mp 295.0–295.5 ꢀC (dec); 1H NMR (CDCl3)
d
¼2.78 (s, 4H), 3.83
(s, 4H), 6.62 (br s, 2H); 19F NMR (acetone-d6, ext. CFCl3)
d
¼ꢁ158.96
4. Kitamura, T.; Fudemoto, H.; Wada, Y.; Murakoshi, K.; Kusaba, M.; Nakashima,
N.; Majima, T.; Yanagida, S. J. Chem. Soc., Faraday Trans. 1997, 93, 221–229.
5. Matsui, M. Fluorine-Containing Dyes. In Functional Dyes; Kim, S.-H., Ed.;
Elsevier: Amsterdam, 2006; Chapter 7 and references cited therein.
6. Frisch, M. J.; Trucks, G. W.; Schlegel, H. B.; Scuseria, G. E.; Robb, M. A.;
Cheeseman, J. R.; Montgomery, J. A., Jr.; Vreven, T.; Kudin, K. N.; Burant, J. C.;
Millam, J. M.; Iyengar, S. S.; Tomasi, J.; Barone, V.; Mennucci, B.; Cossi, M.;
Scalmani, G.; Rega, N.; Petersson, G. A.; Nakatsuji, H.; Hada, M.; Ehara, M.;
Toyota, K.; Fukuda, R.; Hasegawa, J.; Ishida, M.; Nakajima, T.; Honda, Y.; Kitao,
O.; Nakai, H.; Klene, M.; Li, X.; Knox, J. E.; Hratchian, H. P.; Cross, J. B.; Adamo, C.;
Jaramillo, J.; Gomperts, R.; Stratmann, R. E.; Yazyev, O.; Austin, A. J.; Cammi, R.;
Pomelli, C.; Ochterski, J. W.; Ayala, P. Y.; Morokuma, K.; Voth, G. A.; Salvador, P.;
Dannenberg, J. J.; Zakrzewski, V. G.; Dapprich, S.; Daniels, A. D.; Strain, M. C.;
Farkas, O.; Malick, D. K.; Rabuck, A. D.; Raghavachari, K.; Foresman, J. B.; Ortiz, J.
V.; Cui, Q.; Baboul, A. G.; Clifford, S.; Cioslowski, J.; Stefanov, B. B.; Liu, G.;
Liashenko, A.; Piskorz, P.; Komaromi, I.; Martin, R. L.; Fox, D. J.; Keith, T.;
Al-Laham, M. A.; Peng, C. Y.; Nanayakkara, A.; Challacombe, M.; Gill, P. M. W.;
Johnson, B.; Chen, W.; Wong, M. W.; Gonzalez, C.; Pople, J. A. Gaussian 03,
Revision B.02; Gaussian: Pittsburgh PA, 2003.
(br, 2F), ꢁ157.33 (t, J¼16.0 Hz, 2F), ꢁ156.74 to ꢁ156.66 (m, 2F),
ꢁ155.05 (t, J¼16.0 Hz, 2F), ꢁ154.46 (t, J¼16.0 Hz, 2F), ꢁ154.27 (t,
J¼16.0 Hz, 2F), ꢁ143.37 (br s, 2F); EIMS (70 eV) m/z (rel intensity)
696 (Mþ; 20), 376 (32), 375 (28), 374 (37), 356 (47), 334 (100). Anal.
Calcd for C28H10F14N6: C, 48.29; H, 1.45; N, 12.07%. Found: C, 48.54;
H 1.76; N, 12.05%.
5. X-ray crystallography
The single crystals of compounds 3a, 4d, and 6a were obtained
by a solvent diffusion method using hexane and dichloromethane.
Crystal data for 3a: C14H6F7N3, Mw¼349.21, monoclinic, P21/n, Z¼4,
a¼5.391(3), b¼12.168(7), c¼19.82(1) Å,
b
¼86.99(3)ꢀ, Dcalcd
¼
1.786 g cmꢁ3, 10,700 reflections were collected, 2207 unique
7. Becke, A. D. J. Chem. Phys. 1993, 98, 5648–5652.
8. Lee, C.; Yang, W.; Parr, R. G. Phys. Rev. B 1988, 37, 785–789.
(Rint¼0.062), 1558 observed (I>2 (I)), 229 parameters, R1¼0.052,
s
wR2¼0.133, GOF¼1.152, refinement on F2. Crystal data for 4d:
9. Miehlich, B.; Savin, A.; Stoll, H.; Preuss, H. Chem. Phys. Lett. 1989, 157, 200–206.
10. Wong, M. W. Chem. Phys. Lett. 1996, 256, 391–399.
11. Birchall, J. M.; Haszeldine, R. N.; Kemp, J. E. G. J. Chem. Soc. C 1970, 449–455.
12. Sheldrick, G. M. SHELX97, Program for Crystal Structure Refinement; University of
Go¨ttingen: Go¨ttingen, Germany, 1997.
C
20H20F6N4, Mw¼430.40, triclinic, P-1, Z¼1, a¼5.194(1), b¼9.331(2),
c¼10.250(2) Å,
a
¼108.02(1),
b
¼92.71(1),
g
¼94.34(1)ꢀ, Dcalcd
¼
1.521 g/cm3, 4883 reflections were collected, 1662 unique
(Rint¼0.086), 978 observed (I>2 (I)), 137 parameters, R1¼0.0626,
s
13. Crystal Structure ver 3.70, Crystal Structure Analysis Package, RIGAKU and
RIGAKU/MSC, 2000–2005.
wR2¼0.1713, GOF¼0.956, refinement on F2. Crystal data for 6a: