1
714
Can. J. Chem. Vol. 82, 2004
oxidant and extracted with dichloromethane. The organic
phase was washed several times with water and dried with
anhydrous sodium sulfate. The solvent was removed in a ro-
tary evaporator, and the resulting mixture was passed
through a silica gel column using hexane as the solvent to
obtain the corresponding fluoroazobenzene as a crystalline
orange solid. In the case of 2-fluoro-substituted anilines,
fluorophenazines were obtained in low to moderate yields as
yellow crystalline solids.
C H F N ]; exact mass for C H F N : 254.0466; observed:
254.0476.
6
3
2
2
12
6
4
2
3,3′,4,4′-Tetrafluoroazobenzene (2g)
–
1
Orange crystals; yield 60%; mp 70–72 °C. IR (neat, cm )
1
1275 (C–F). H NMR (CDCl ) δ (ppm): 7.36 (m, 2H, aro-
3
1
9
matic), 7.78 (m, 4H, aromatic). F NMR (CDCl ) δ (ppm):
–129.3 (s, 2F), –132.4 (s, 2F). EI-MS (70 eV) m/z: 254
3
+
+
+
(41%) [M ], 141 (45%) [M – C H F ], 113 (100%) [M –
6
3 2
C H F N ]; exact mass for C H F N : 254.0466; observed:
6
3
2
2
12
6
4
2
2
,2′-Difluoroazobenzene (2a)
254.0471.
–
1
Orange crystals; yield 52%; mp 94–96 °C. IR (neat, cm )
1
1
219 (C–F). H NMR (CDCl ) δ (ppm): 7.5 (m, 4H, aro-
2,2′,3,3′,4,4′,5,5′,6,6′-Decafluoroazobenzene (2h)
3
matic CH), 7.73 (m, 2H, aromatic), 8.05 (td, 2H, aromatic).
Red–orange crystals; yield 60%; mp 142–143 °C. IR
1
9
–1
1
F NMR (CDCl ), δ (ppm): –121.3 (s, 2F). EI-MS (70 eV)
(neat, cm ) 1258 (C–F). H NMR (CDCl ) δ (ppm): 7.36
3
3
+
+
19
m/z: 218 (45%) [M ], 123 (48%) [M – C H F], 95 (100%)
(m, 2H, aromatic), 7.78 (m, 4H, aromatic). F NMR
6
4
+
+
[
M – C H FN ], 75 (25%) [M – C H F N ]; exact mass
(CDCl ) δ (ppm): –151.9 (m, 6F), –164.7 (m, 4F). EI-MS
6
4
2
6
5
2
2
3
for C H F N : 218.0653; observed: 218.0663.
(70 eV) exact mass for C F N : 361.9901; observed
1
2
8
2
2
12 10
2
3
61.9890.
3
,3′-Difluoroazobenzene (2b)
–
1
Orange crystals; yield 50%; mp 70–72 °C. IR (neat, cm )
3,8-Difluorophenazine (3d)
Yellow crystals; yield 20%; mp 169–171 °C. IR
1
1
247 (C–F). H NMR (CDCl ) δ (ppm): 7.24 (m, 2H, aro-
3
–
1
matic), 7.52 (q, 2H, aromatic), 7.62 (dd, 2H, aromatic), 7.78
(neat, cm ) 1535 (C=C), 1478 (C=C), 1638 (C=N), 1201
d, 2H, aromatic). 19F NMR (CDCl ) δ (ppm): –108 (s, 2F).
1
(
(C–F). H NMR (CDCl3) δ (ppm): 8.35 (m, 1H, aromatic),
3
+
+
19
EI-MS (70 eV) m/z: 218 (32%) [M ], 123 (22%) [M –
8.42 (m, 1H, aromatic), 8.54 (m, 1H, aromatic), F NMR
+
+
C H F], 95 (100%) [M – C H FN ], 75 (24%) [M – C H F N ];
exact mass for C H F N : 218.0653; observed: 218.0655.
(CDCl3) δ (ppm): –125 (s, 2F). EI-MS (70 eV) exact mass
for C12H6F2N2: 216.0499; observed 216.0480.
6
4
6
4
2
6 5 2 2
1
2
8
2
2
4
,4′-Difluoroazobenzene (2c)
2,7-Difluorophenazine (3e)
–1
Orange crystals; yield 94%; mp 99–100 °C. IR (neat, cm )
Yellow crystals; yield 25%; mp 205–206 °C. IR
1
–1
1
231 (C–F). H NMR (CDCl ) δ (ppm): 7.3 (dd, 4H, aro-
(neat, cm ) 1533 (C=C), 1487 (C=C), 1639 (C=N), 1104
3
1
9
1
matic), 8.04 (dd, 4H, aromatic). F NMR (CDCl ) δ (ppm):
(C–F). H NMR (CDCl3) δ (ppm): 8.25 (m, 1H, aromatic), 8.
3
+
19
–
106 (s, 2F). EI-MS (70 eV) m/z: 218 (29%) [M ], 123
55 (m, 1H, aromatic), 8.65 (m, H, aromatic). F NMR
+
+
(
[
20%) [M – C H F], 95 (100%) [M – C H FN ], 75 (18%)
M – C H F N ]; exact mass for C H F N : 218.0653; ob-
(CDCl3) δ (ppm): –123.5 (s, 2F). EI-MS (70 eV) exact mass
for C12H6F2N2: 216.0499; observed 216.0489.
6
4
6
4
2
+
6
5
2
2
12
8
2
2
served: 218.0650.
2
,3,4,5,7,8,9,10-Octafluorophenazine (3h)
Yellow crystals; yield 25%; mp 233–234 °C. IR
2
,2′,4,4′-Tetrafluoroazobenzene (2d)
Orange crystals; yield 52%; mp 150–152 °C. IR
–
1
19
(
neat, cm ) 1638 (C=C), 1478 (C=C), 1201 (C–F).
F
–
1
1
NMR (CDCl ) δ (ppm): –155.5 (s, 2F), –157 (s, 2F), –162.4
(
(
neat, cm ) 1270 (C–F). H NMR (CDCl ) δ (ppm): 7.01
m, 4H, aromatic), 7.85 (m, 2H, aromatic). F NMR
3
3
1
9
s, 2F), 166 (s, 2F). EI-MS (70 eV) exact mass for C F N :
(
12 8 2
3
23.9934; observed 323.9920.
(
(
1
2
CDCl ) δ (ppm): –101.2 (s, 2F) –116.3 (s, 2F). EI-MS
3
+
+
70 eV) m/z: 254 (40%) [M ], 141 (45%) [M – C H F ],
6 3 2
+
13 (100%) [M – C H F N ]; exact mass for C H F N :
Acknowledgements
6
3
2
2
12
6
4
2
54.0466; observed: 254.0407.
Financial support by the National Council for Science and
Technology (CONACyT) of Mexico (Grant 0762-M9109) is
gratefully acknowledged. We thank Professor Miguel A.
García-Garibay from the University of California at Los An-
geles for help with MS measurements.
2
,2′,5,5′-Tetrafluoroazobenzene (2e)
Orange crystals; yield 62%; mp 128–130 °C. IR
–
1
1
(
(
(
(
(
2
neat, cm ) 1253 (C–F). H NMR (CDCl ) δ (ppm): 7.25
3
1
9
m, 4H, aromatic), 7.54 (m, 2H, aromatic). F NMR
CDCl ) δ (ppm): –116.3 (s, 2F), –127.8 (s, 2F). EI-MS
3
+
+
70 eV) m/z:254 (45%) [M ], 141 (50%) [M – C H F ], 113
References
6
3 2
100%) [M+ – C H FN ]; exact mass for C H F N :
6
4
2
12
6
4
2
1
2
. H.W. Russ and H. Tappe. Eur. Pat. Appl. EP 629, 667 (1994).
. Y. Onogi, T. Hayashi, Y. Mizushima, and M. Yamamoto. Nip-
pon Kagaku Kaishi, 815 (1990).
54.0466; observed: 254.0477.
2
,2′,6,6′-Tetrafluoroazobenzene (2f)
3
. H. Yamamoto and A. Nishida. Nippon Kagaku Kaishi, 2338
Orange crystals; yield 65%; mp 121–123 °C. IR
(
1985).
–
1
1
(
(
(
(
neat, cm ) 1017 (C–F). H NMR (CDCl ) δ (ppm): 6.85
4. H. Sakai, J. Anzai, A. Ueno, and T. Osa. Nippon Kagaku
Kaishi, 1194 (1985).
5. K. Kimura, T. Suzuki, and M. Yokoyama. Solid State Ionics,
40, 666 (1990).
3
1
9
m, 4H, aromatic), 7.20 (m, 2H, aromatic). F NMR
CDCl ) δ (ppm): –125.3 (s, 4F). EI-MS (70 eV) m/z: 254
47%) [M ], 141 (72%) [M – C H F ], 113 (100%) [M –
3
+
+
+
6
3 2
©
2004 NRC Canada