Vol. 25, No. 8 (2013)
Synthesis of Dicationic Carbazole and 4'-Amino-(3,3'-bipyridine)-4-ol 4633
1
-MeOH 20:1); H NMR (CDCl
(
CH
2
Cl
2
3
) δ: 7.23 (dd, J = 7.9,
42.5 mL 35 % sulphuric acid and heated to 80 ºC. The zinc
powder (4.88 g) was fractionated into the reaction solution.
At the end of adding zinc, 20 mL 35 % sulphuric acid was
dropped into the solution and continued adding zinc powder
(4.88 g) again. The mixture was stirred for 0.5 h and cooled to
room temperature. With 50 % sodium hydroxide solution to
adjust the solution pH to 11 and evaporating the solvent, the
residue was dried in vacuum and extracted successively with
hot ethanol and hot isopropanol. Finally, the extracted liquids
were combined and concentrated to dryness. 4,4'-diamino-3,3'-
bipyridine (5) was separated with neutral alumina column
6
.9 Hz, 1H, H ), 7.45 (d, J = 8.3 Hz, 1H, H ), 8.20 (d, J = 6.5
5
4
-1
6 2
Hz, 1H, H ), 8.39 (s, 1H, H ); IR (KBr, film, νmax, cm ): 3098,
1
593 (C=C, C=N), 1468, 1424, 1245 (N-O), 1014, 891, 667
+
C-Br); MS (ESI) m/z: 174, 176 [M + H] . The H NMR data
1
(
9
were similar to that in the reference .
-Bromo-4-nitropyridine-N-oxide (2) and 5-bromo-2-
nitropyridine (3): 3-Bromopyridine-N-oxide (30 g, 0.172
3
mol) and 48 mL of concentrated sulphuric acid were mixed in
0-5 ºC, then the mixed acid of 48 mL of concentrated sulphuric
acid and 72 mL of concentrated nitric acid was added dropwise.
When the dropping was over, the solution was stirred at 90 ºC
for 5 h. Then the yellow reaction mixture was dumped into
chromatography using CH
Yield: 0.44 g, 47.3 %. m.p. 289-291 ºC (reference value : 283-
285 ºC); R = 0.90 (alumina plate, CH Cl -MeOH 10:1), 0.74
(silica gel plate, CH Cl -MeOH-NH ·H O 30:10:1); H NMR
(DMSO-d ) δ: 5.54 (2H, NH ), 5.56 (2H, NH ), 6.65 (d, J =
5.6 Hz, 2H, H , H5'), 7.87 (s, 2H, H , H2'), 8.03 (d, J = 5.6 Hz,
2H, H , H6'); IR (KBr, νmax, cm ): 3428 (NH ), 3087, 1642,
1583 (C=C, C=N), 1496, 1414, 995, 824; HRMS (ESI) m/z:
2 2
Cl /MeOH (8:1, v:v) as an eluent.
8
2
00 g of crushed ice in mixing fully and adjusted the pH to 7
f
2
2
1
with aqueous ammonia solution, a large number of yellow
needle-like solid was precipitated, filtered, washed using a
small amount of ice water, dried and recrystallized by
dichloromethane/petroleum ether to obtain yellow needle-like
crystals, 3-bromo-4-nitropyridine-N-oxide (2); the mother
liquor was for further distillation and the residue was treated
2
2
3
2
6
2
2
5
2
-1
6
2
+
11 4
calcd. for C10H N [M + H] 187.0984, found 187.0980.
by silica gel column chromatography with CH Cl
2
2
as an eluent.
4'-Amino-(3,3'-bipyridine)-4-ol (6): 4,4'-Dinitro-3,3'-
bipyridine-N,N'-dioxide and the catalyst (10 % Pd/C or Raney
Ni) were added to the ethanol. A suspension was heated to 50
ºC and accessed hydrogen with TLC monitoring the reaction
progress. After the reaction end, the mixture was filtered and
the filtrate was concentrated into dryness. The residue was
The first group was divided into 5-bromo-2-nitropyridine (3)
and the second group was divided into 3-bromo-4-nitropyridine-
N-oxides (2).
3
-Bromo-4-nitropyridine-N-oxides (2): Yield: 18.5 g,
10
4
0
9.1 %. m.p. 159-160 ºC (reference value : 152-153 ºC); R
.19 (CH
f
=
) δ: 8.00 (d, J = 7.2 Hz, 1H,
1
); H NMR (CDCl
2
Cl
2
3
purified by silica gel column chromatography, using CH
2 2
Cl /
H
5
), 8.16 (d, J = 7.2 Hz, 1H, H
6
), 8.48 (d, J = 1.9 Hz, 1H, H
IR (KBr, νmax, cm ): 3099, 1588 (C=C, C=N), 1551 (NO
501, 1339 (NO ), 1294 (N-O), 1254, 1050, 643 (C-Br); MS
APCI) m/z: 219, 221 [M + H] . The H NMR data were similar
2
);
MeOH/NH ·H O (30:10:1, v/v/v) as an eluent. The first group
3
2
-1
2
),
was 4,4'-diamino-3,3'-bipyridine (5) and the second group was
4'-amino-(3,3'-bipyridine)-4-ol (6). Yield was not calculated
in virtue of investigating the solvent and catalyst quantity for
1
2
+
1
(
10
1
to that in the reference .
the catalytic hydrogenation research by H NMR. m.p. 296-
1
2
5
-Bromo-2-nitropyridine (3): Yield: 2.0 g, 5.7 %. m.p.
298 ºC (reference value : 290 ºC); R
CH Cl -MeOH-NH ·H O, 30:10:1, v/v/v); H NMR (DMSO-d
δ: 5.73 (br, 2H, NH ), 6.29 (d, J = 7.1 Hz, 1H, H ), 6.63(d, J =
5.6 Hz, 1H, H5'), 7.75 (dd, J = 7.2, 1.6 Hz, 1H, H ), 7.80 (d, J =
1.6 Hz, 1H, H ), 7.96 (s, 1H, H2'), 8.01 (d, J = 5.6 Hz, 1H, H6');
IR (KBr, νmax, cm ): 3323 (OH), 3228 (NH
1592 (C=C, C=N), 1516, 1384, 1188, 997, 830; HRMS (ESI)
f
= 0.39 (silica gel plate,
11
1
1
60-162 ºC (reference value : 149-151 ºC); R
f
= 0.88 (CH
) δ: 8.20 (d, J = 1.2 Hz, 2H, H , H ), 8.71-
); C NMR (CDCl3) δ: 119.38, 127.10, 142.44,
2 2
Cl );
2
2
3
2
6
)
1
H NMR (CDCl
3
2
3
2
5
1
3
8
.72 (m, 1H, H
50.15, 155.20; IR (KBr, νmax, cm ): 1635 (C=C, C=N), 1529
), 1443, 1376, 1349 (NO ), 1248, 1086, 1008, 856, 683,
23 (C-Br); MS (ESI) m/z: 203, 205 [M + H] . The H NMR,
6
6
-1
1
2
-1
(NO
2
2
2
), 3088, 1633,
+
1
6
13
11,12
+
C NMR and IR data were similar to that in the reference
,4'-Dinitro-3,3'-bipyridine-N,N'-dioxide (4): 3-Bromo-
-nitropyridine-N-oxide (18 g, 0.083 mol) and 21.5 g copper
.
m/z: calcd. for C10
3,6-Diazacarbazole (7): 4,4'-Diamino-3,3'-bipyridine
(1.80 g and 0.0097 mol) and 27.5 g anhydrous ZnCl were
10 3
H N O [M + H] 188.0824, found 188.0825.
4
4
2
powder were added to 90 mL DMF and stirred for 5 h at 105 ºC.
After the reaction over, the reaction solution was filtered. The
cake residue was washed with hot DMF (90 mL × 4 mL, 120-
mixed into round-bottomed flask and heated to 350-375 ºC
for 4 h. Afted cooled to room temperature, 65 mL water was
added to the reaction mixture forming a light black solution
and then 50 % sodium hydroxide solution was used for alka-
lization, gray solid precipitated, filtered and extracted with
hot ethanol (50 mL × 5 mL). Collected ethanol solution was
concentrated into dryness and the residue was purified by silica
1
30 ºC) and combined the filtrate. It evaporated to ca. 40 mL
volume. Cooling to room temperature, it was dropped ca.
0 mL ammonia aqueous solution until it changed into green
3
and a yellow precipitate appeared. Through filtration, dryness
and recrystallization with DMF, 4,4 '-dinitro-3,3'-bipyridine-
N,N'-dioxide (4) as yellow powder was obtained. Yield: 6.62
2 2
gel column chromatography using CH Cl /MeOH (10:1, v:v)
as an eluent to get 3,6-diazacarbazole (7).Yield: 1.08 g, 65.8 %.
8
1
8
g, 57.3 %. m.p. > 300 ºC (reference value > 300 ºC); H NMR
m.p. >300 ºC (reference value >300 ºC); R
f
= 0.18 (CH
) δ: 7.58 (d, J = 5.7 Hz, 2H,
), 8.52 (d, J = 5.7 Hz, 2H, H , H ), 9.46 (s, 2H, H , H ),
12.18 (br, 1H, H ); IR (KBr, νmax, cm ): 2921, 2670 (N-H),
1627, 1577 (C=C, C=N), 1470, 1384, 1204, 803, 663; HRMS
2 2
Cl -
1
(
CF
3
COOD) δ: 8.46-8.48 (m, 2H, H
3
, H3'), 8.82-8.87 (m, 4H,
, H6'); IR (KBr, νmax, cm ): 3071, 1603 (C=C, C=N),
), 1348 (NO ), 1246 (N-O); MS (ESI) m/z:
MeOH 10:1); H NMR (DMSO-d
, H
6
-1
H
2
, H2', H
6
H
1
8
2
7
4
5
-1
1
567, 1517 (NO
38 [M + CH COOH] .
,4'-Diamino-3,3'-bipyridine (5): 4,4'-Dinitro-3,3'-
bipyridine-N,N'-dioxide (1.39 g, 0.0050 mol) was added to
2
2
9
+
3
3
+
4
(ESI) m/z: calcd. for C10
170.0706.
8 3
H N [M + H] 170.0718, found