JOURNAL OF CHEMICAL RESEARCH 2008 723
Table
1
Nitration of aromatic compounds using AMA and
General procedure for nitration of aromatic compounds
Mg(N03
h
6H20
CAUTION: The isolation of nitrated products must be
carried out carefully with due precautions as some such
compounds are known human carcinogens.
Entry
Aromatic
compounds
Reaction
time
Nitrated
compound/% yield"
NO,
3
0 min
o - 0 H
(
1) Aromatic compounds without amino groups
Mg(N03h-6H20 (1 mmol) was added to a mixture of MeS03H
1.0 ml) and A1203 (0.27 g, 3.0 mmol). After a few minutes the
0
2
N
-0-0 Hd -~ H
2a' (45)
Ia
(
2
a
(47)
aromatic compound (1 mmol) was added to this mixture. The mixture
was stirred at room temperature for the appropriate time (Table 1).
Then the mixture was poured into water (20 ml) and extracted four
times with ethyl acetate (40 ml). The organic layer was washed with a
saturated solution of sodium bicarbonate (20 ml), dried over Na2S04
and evaporated under reduced pressure. The resulting product was
purified by preparative TLC (silica) using a solvent mixture of
EtOAc-hexane, 1:2 as eluent to afford the pure nitrated derivative.
N 02
2
90 min
H
0 2 C - o - O
H
2
b (98)
N 02
3
C
1 - o - 0 H
60 min
C1-d-OH
Ie
2
e (95)
(
2) Aromatic compounds with amino groups
N 02
The reaction conditions were as described above but the work-up
was a little different. After the reaction was completed the mixture
was poured into a saturated solution of sodium bicarbonate (20 ml)
and extracted five times with ethyl acetate (40 ml). Then the organic
layer was dried over Na2S04 and evaporated under reduced pressure.
The resulting product was purified as described above.
4
H
2 N - 0 - 0 H
6h
H
2 N - o - O
H
Id
2
d (98)
N 02
5
6
0 2 N - 0 - 0 H
24 h
4
-Nitrophenol (2a): Yellow powder; m.p. 112-114°C (lit.,42
14°C); IR(KBr) (vrnax/cm-I): 3331, 1614, 1592, 1500, 1346; IH NMR
250 MHz, CDCI3): /)8.18 (d, 2H, J= 5.50 Hz, ArIl), 7.00 (d, 2H,
J= 5.49 Hz,ArIl), 6.35 (s, lH,-OH); GC-MS/EI: m/z (%) = 139(M+, 14),
09 (50), 81 (33),65 (84), 53 (31),46 (22), 39 (100), 30 (77), 28 (41).
-Nitrophenol (2a'): Yellow powder; m.p. 42-44°C (lit.,4o 45°C);
IR(KBr) (vrnax/cm-I): 3241, 1623, 1606, 1593, 1538, 1479; IH NMR
250 MHz, CDCI3): /) 10.5 (s, lH, -OH), 8.10 (d, lH, J = 8.50 Hz,
Ie
02N-o-OH
1
2
e (95)
(
N 02
35 min
1
O
H
C
- o - O
H
2
2
f (98)
(
N 02
7
8
O
H
C
- 0 - 0 M
e
3
0 min
ArIl), 7.59 (m, lH, ArIl), 7.16 (d, lH, J = 8.4 Hz, ArIl), 7.00 (m,
lH, ArIl); GC-MS/EI: m/z (%) = 139 (M+, 40), 109 (35), 81 (55),65
60),53 (38), 39 (100), 30 (66).
4-Hydroxy-3-nitrobenzoic acid (2b): Yellow powder; m.p. 179-
O
H
c - - d - O
M
e
Ig
(
2
g (95)
0
2N
182°C (lit.,43 184°C); IR(KBr) (vrnax/cm-I): 3309,3089,2842, 1689,
4h
1
627,1539,1434,1342; IH NMR (250 MHz, DMSO): /) 11.73 (brs,
C
l ~ C
H
O
lH, -C02H), 10.23 (brs, lH, -OH), 8.33 (s, lH, ArIl), 7.98 (d, lH,
J= 7.9 Hz), 7.16 (d, lH,J= 7.9 Hz,ArIl); GC-MS/EI: m/z (%) = 183
2
h (87)
(
M+, 7), 149 (22),129 (17), 97 (38), 57 (100).
-Chloro-2-nitrophenol (2e): Yellow powder; m.p. 84-86°C (lit.,42
5-89°C); IR(KBr) (vrnax/cm-I): 3490, 1631, 1531, 1469, 1384,
C
H
O
C
H
O
4
8
9
Q -O H 40 min
0
2N-o-OH
1346, 1238; IH NMR (250 MHz, DMSO): /) 11.33 (brs, lH, -OH),
7.90 (s, lH, ArIl), 7.54 (d, lH,J= 8.9 Hz), 7.14 (d, lH,J= 8.9 Hz,
ArIl); GC-MS/EI: m/z (%) = 173 (M+, 16), 156 (7), 143 (26), 128
I i
2i (90)
HO
HO
(10),115 (41), 99 (39), 73 (29),63 (100),51 (20),37 (13), 30 (26).
1
0
30 min
4-Amino-2-nitrophenol (2d): Yellow powder; m.p. 123-125°C
o-O H
02N-o-OH
(lit.,42 125-127°C); IR(KBr) (vrnax/cm-I): 3460, 3255, 2958, 1627,
Ij
2j (85)
1
546, 1469, 1373, 1234; IH NMR (250 MHz, DMSO): /)9.64 (brs,
N 02
2
H, -NH2), 8.92 (brs, lH, -OH), 7.30 (s, lH, ArIl), 7.23 (d, lH,
1
1
24 h
H2N-0-Br
J= 8.4 Hz), 7.09 (d, lH,J= 8.4 Hz,ArIl); GC-MS/EI: m/z (%) = 154
(M+, 5), 137 (14),124 (6),108 (12), 79 (47), 53(100), 28 (10).
Ik
H
2
N-o-B r
2
,4-Dinitrophenol (2e): Yellow powder; m.p. 107-110°C (lit.,42
08-112°C); IR(KBr) (vrnax/cm-I): 3587,3529, 1608, 1569, 1531,
523,1438,1357,1280; IH NMR (250 MHz, DMSO): /) 11.02 (brs,
2
k (95)
N 02
1
1
1
1
2
3
o - C
l
20 h
>
2 N
D
- C
l
o - C
l
11
lH, -OH), 8.65 (s, lH, ArIl), 8.26 (d, lH, J= 9.3 Hz), 7.22 (d, lH,
J= 9.2 Hz, ArIl); GC-MS/EI: m/z (%) = 184 (M+, 4),167 (10),129
2
1(35)b 21' (65)b
(10), 111 (12),85 (22), 69 (100).
02N
24 h
4-Hydroxy-3-nitrobenzaldehyde (21): Yellow powder; m.p. 138-
1
40°C (lit.,43 140-141°C); IR(KBr) (vrnax/cm-I): 3236,2816, 1693,
o-CN
1
620, 1562, 1423, 1334, 1269, 1126; IH NMR (250 MHz, CDCI3):
2
m (82)
/)11.01 (brs, lH, -OH), 9.94 (s, lH, -CHO), 8.63 (s, lH, ArIl), 8.14
(d, lH,J= 3.5 Hz), 7.33 (d, lH,J= 3.5 Hz,ArIl); GC-MS/EI: m/z
0
2N
1
1
4
5
48 h
(%) = 167 (M+, 10), 149 (25), 129 (11), 111 (11),85 (23), 69 (100).
4
-Methoxy-3-nitrobenzaldehyde (2g): Yellow powder; m.p. 99-
o-N0
2
1
1
01°C (lit.,42 97-100°C); IR(KBr) (vrnax/cm-I): 3487, 3001, 2623,
697, 1620, 1539, 1431, 1357, 1288; IH NMR (250 MHz, DMSO):
2
n (31)
H
0 D - 0 H
6h
decomposed
/)9.84 (s, lH, -CHO), 8.10 (s, lH, ArIl), 8.07 (d, lH, J= 8.7 Hz,
ArIl), 7.45 (d, lH,J= 8.7 Hz,ArIl), 3.96 (s, 3H,-OMe); GC-MS/EI:
m/z (%) = 181 (M+, 6), 167 (11), 149 (11), 129 (8), 111 (8),85 (13),
1
0
6
9 (100).
4
-Chloro-3-nitrobenzaldehyde (2h): Yellow powder; m.p. 140-
1
6
6h
decomposed
O -O H
1
47°C (lit.,42 148-150°C); IR(KBr) (vrnax/cm-I): 3101,2873,2715,
2596, 1701, 1593, 1431, 1330; IH NMR (250 MHz, DMSO): /) 10.1
s, lH, -CHO), 8.22 (s, lH, ArIl), 7.90 (d, lH, J = 3.1 Hz, ArIl), 7.55
Ip
(
"
Yields are of the isolated compounds.
bProportions were
(d, lH, J= 3.1 Hz, ArIl); GC-MS/EI: m/z (%) = 185 (M+, 9), 167
determined by'H NMR.
(10),149 (22), 129 (15), 97 (19), 73 (45),57(100).