Solvent-free, one-pot conjugate addition of benzyl bromides to β-nitroalkenes mediated by magnesium powder

Article abstract of DOI:10.1055/s-0028-1083329

A convenient and efficient methodology for conjugate addition of benzyl bromides to β-nitrostyrenes mediated by magnesium powder in one pot under solvent-free conditions at 0 °C has been developed. Advantages of this method are excellent yields, short rea

Full text of DOI:10.1055/s-0028-1083329

PAPER
597
Solvent-Free, One-Pot Conjugate Addition of Benzyl Bromides to
b-Nitroalkenes Mediated by Magnesium Powder
O
a
ne-Pot Conjugate
Add
e
ition of Ben
i
zyl Bromide
S
to
b
-Nitroalk
h
enes i,a Jin-Xian Wang*a,b
Institute of Chemistry, Department of Chemistry, Northwest Normal University, 967 An Ning Road (E.), Lanzhou 730070, P. R. of China
Fax +86(931)7768159; E-mail: Wangjx@nwnu.edu.cn
b
State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou 730000, P. R. of China
Received 30 June 2008; revised 16 October 2008
achieved the solvent-free conjugate addition of orga-
nozinc halides to b-nitrostyrenes in the absence of a cata-
lyst;16 polyfunctional nitro compounds were obtained in
two to three steps from the b-nitrostyrenes. To make the
Abstract: A convenient and efficient methodology for conjugate
addition of benzyl bromides to b-nitrostyrenes mediated by magne-
sium powder in one pot under solvent-free conditions at 0 °C has
been developed. Advantages of this method are excellent yields,
short reaction times, operational simplicity, and avoidance of the application of nitroalkenes even more attractive, we have
use of organic solvents.
focused our attempts on the development of more conve-
nient, rapid, and ‘green’ reactions mediated by inexpen-
sive metals, instead of organometallics, as reaction
substrates.
Key words: b-nitrostyrenes, benzyl bromide, conjugate addition,
solvent-free, magnesium powder
Herein, we report our improvements: a handy and low-
cost conjugate addition, mediated by magnesium powder,
of benzyl bromide reagents to b-nitrostyrenes in one pot
under solvent-free and catalyst-free conditions to give the
corresponding 1,2-diaryl-2-nitropropanes in high to ex-
cellent yields.
Conjugate addition of organometallic reagents to power-
ful Michael acceptors has a vital function in the formation
of C–C bonds.1 Among good acceptors for conjugate ad-
dition, b-nitrostyrenes, due to their strongly electron-
withdrawing group,2 can be easily transformed into a
variety of valuable functionalities such as amines,
ketoximes, hydroxylamines, and nitroalkanes.3 Therefore,
conjugate addition to b-nitrostyrenes has received much
attention in recent years.
In order to investigate the effects of different metals and
solvents on the yields of the reaction, a mixture of b-ni-
trostyrene (1a), benzyl bromide (2a), solvent, and metal
was stirred at 0 °C (Table 1).
There have been many reports on the conjugate addition
of b-nitrostyrenes mediated by organometallics including
Grignard reagents,4 alkyllithiums,5 and organoalumi-
nums.6 However, most of them were not satisfactory due
to undesirable side reactions and poor conversion.7 More-
over, the organometallic reagents needed to be prepared
beforehand and the process was rigorous. Researchers
have also focused their works on catalytic 1,4-conjugate
addition to nitrostyrenes using, for example, copper metal
or copper salts.8 Later, these reactions were promoted by
metallic indium,9 samarium,10 and zinc11 in organic sol-
vent in the absence of a catalyst. The progress of these ap-
proaches is gratifying, but one of the drawbacks is
chemical pollution caused by the use of organic solvents.
Hence, we should make an effort to explore more effi-
cient, environmentally benign, handier procedures.
We first examined various metals for the mediation of the
reaction. From Table 1, it can be seen that most of the
metals examined, such as tin, iron, aluminum, and zinc,
did not give rise to the expected products even after pro-
longed reaction times (Table 1, entries 1–4), only magne-
sium powder gave the desired product 3a after 1.5 hours
(Table 1, entry 5).
Next we explored the conjugate addition of benzyl bro-
mide (2a) to b-nitrostyrene (1a) mediated by magnesium
using different solvents. We found that the desired prod-
uct 3a was not observed after prolonged reaction times
when distilled water or dimethyl sulfoxide was used as
solvent (Table 1, entries 6 and 7). When the solvent was
diethyl ether, ethanol, or N,N-dimethylformamide
(Table 1, entries 8–10), b-nitrostyrene (1a) could be ben-
zylated to give 1-nitro-2,3-diphenylpropane (3a) in low
yields. Even the use of magnesium in tetrahydrofuran,
which was very efficient for the conjugate addition of b-
nitrostyrene (1a), did not improve our results and gave
moderate yields (Table 1, entry 11). It is noteworthy that
the product yield was higher (72%) in the absence of sol-
vent in comparison to that in tetrahydrofuran (56%).
Hence, solvent-free conditions were necessary for suc-
cessful conjugate addition to b-nitrostyrenes, which is a
great improvement in reducing chemical pollution.
Much research work on 1,4-conjugate addition reactions
conducted by organozinc halides has been performed in
our laboratory. We have studied the smooth conjugate ad-
dition between b-nitrostyrenes and functionalized orga-
nozinc halides using copper(II) acetate12 as a catalyst
instead of copper(I) cyanide–bis(lithium chloride),13,14
and nickel(II) catalyst.15 In addition, we have successfully
SYNTHESIS 2009, No. 4, pp 0597–0601
x
x
.
x
x
.2
0
0
9
Advanced online publication: 27.01.2009
DOI: 10.1055/s-0028-1083329; Art ID: F14708SS
© Georg Thieme Verlag Stuttgart · New York

598
W. Shi, J.-X. Wang
PAPER
Table 1 Conjugate Addition of Benzyl Bromide (2a) to b-Nitro-
styrene (1a) Mediated by Different Metals in Different Solventsa
Table 2 Addition Reactions of Benzyl Bromide to Nitroalkenes
Mediated by Magnesium in One Pot under Solvent-Free Conditionsa
O2N
Ar2CH2Br 2
Mg, solvent-free, 0 °C
NO2
Br
NO2
Ar1
NO2
Ar2
2a
Ar1
M, solvent, 0 °C
1
3
1a
3a
Entry Ar1
Ar2
Product Time Yieldb,c,d
(h) (%)
Entry
Mediator
Solvent
–
Time (h) Yieldb,c (%) of 3a
1
2
Sn
10
10
10
10
1.5
26
18
5
n.r.
n.r.
n.r.
n.r.
72
1
2
Ph
Ph
3a
3b
3c
3d
3e
3f
1.5 72 (66)
Fe
–
4-ClC6H4
4-MeOC6H4
4-MeC6H4
2-MeOC6H4
2-ClC6H4
2,4-Cl2C6H3
3,4-(MeO)2C6H3
3-BrC6H4
2-furyl
Ph
2
2
78 (67)
85 (81)
3
Al
–
3
Ph
4
Zn
–
4
Ph
1.5 84
5
Mg
Mg
Mg
Mg
Mg
Mg
Mg
–
5
Ph
2
2
2
2
2
77 (70)
6
H2O
DMSO
Et2O
EtOH
DMF
THF
n.r.
n.r.
42
6
Ph
83 (76)
80
7
7
Ph
3g
3h
3i
8
8
Ph
77
9
5
33
9
Ph
72
10
11
5
37
10
11
12
13
14
15
16
Ph
3j
1.5 75 (72)
1.5 80 (78)
4.5
56
2-thienyl
Ph
Ph
3k
3l
a Reaction conditions: Mg powder or other metals (4 mmol), BnBr
(2a, 4 mmol), b-nitrostyrene (1a, 2 mmol), solvent (2 mL), 0 °C.
b Isolated yields.
4-ClC6H4
4-ClC6H4
4-ClC6H4
4-BrC6H4
4-BrC6H4
3
3
3
3
3
75 (73)
71
4-MeOC6H4
4-MeC6H4
Ph
3m
3n
3o
3p
c n.r. = no reaction; almost all of the b-nitrostyrene was recycled.
78
67
In order to explore the applications of this reaction, we
performed it using benzyl bromide (2a) and substituted
benzyl bromides 2 and nitroalkenes 1 under solvent-free
conditions directly mediated by magnesium at 0 °C
(Table 2). The results in Table 2 reveal that the nature of
the substitution pattern on the phenyl ring of the nitroalk-
ene 1 plays a major role in determining the yields of the
reaction. High yields can be achieved with shorter times
in the case of many nitrostyrenes 1 bearing electron-
donating groups or moderate electron-withdrawing
groups on the phenyl ring Ar1. However, b-nitrostyrenes
1 bearing strong electron-withdrawing groups, such as the
4-ClC6H4
65
a All reactions were performed with Ar2CH2Br 2 (4 mmol), Mg pow-
der (4 mmol), b-nitroalkenes 1 (2 mmol), 0 °C, solvent-free condi-
tions.
b Isolated yields.
c All products were characterized by IR, 1H NMR, 13C NMR, MS.
d Values in brackets are from the reaction of organozinc reagents
without solvent.16b
All chemicals were obtained from commercial sources. Melting
nitro group, on phenyl ring Ar1 did not give products 3 points were measured on an X-4 electrothermal micro melting point
apparatus and are uncorrected. IR spectra were measured using an
even after prolonged reaction times. The heterocyclic ni-
Alpha Centauri FT-IR spectrophotometer. 1H NMR and 13C NMR
troalkenes also gave adducts 3j and 3k in moderate yields
and short times (Table 2, entries 10 and 11).
spectra (400 MHz and 100 MHz, respectively) were recorded on
Bruker AC-E 400 MHz spectrometer in CDCl3 with TMS as an in-
In conclusion, we have developed a new and convenient ternal standard. Mass spectra were performed on QP-1000A GC-
MS spectrometer by EI ionization at 70 eV. Elemental analyses
were performed on a Perkin-Elmer PE 2400 instrument. Purifica-
tion of products was performed by flash chromatography on 200–
procedure for the conjugate addition of benzyl bromides
to b-nitroalkenes mediated by magnesium powder in one
pot under solvent-free and catalyst-free conditions. Com-
300 mesh silica gel (petroleum ether–EtOAc, 15:1). All the isolated
pared with previously reported methods,12–14,16b the ad-
products were characterized by IR, 1H and 13C NMR, and MS, and
vantages of the present method are: (a) excellent yields
when magnesium powder is used as medium (the yields
elemental analysis for all the new compounds.
increased to 72–85% from 66–81%); (b) the reaction time 1,2-Diaryl-3-nitropropanes 3; General Procedure
Mg powder (4 mmol) and nitroalkene 1 (2 mmol) were placed in a
dried round-bottom flask. Then benzyl bromide 2 (4 mmol) was
added slowly. The resulting mixture was stirred at 0 °C and the re-
is shortened to 1.5–3 hours from 3–5 hours; and (c) the
simplicity of the operation.
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One-Pot Conjugate Addition of Benzyl Bromides to b-Nitroalkenes
599
action was monitored (TLC). After complete conversion, sat.
NH4Cl soln (10 mL) was poured into the mixture. The mixture was
extracted with Et2O (3 × 10 mL) and the organic layer was separat-
ed, dried (anhyd MgSO4), and evaporated. The crude mixture was
subjected to column chromatography (silica gel, PE–EtOAc) to give
the pure product.
MS (EI, 70 eV): m/z = 271 (M+), 224, 210, 180, 134, 91, 77.
2-(2-Chlorophenyl)-1-nitro-3-phenylpropane (3f)
Pale yellow oil.16b
IR (KBr): 3064, 3029, 2922, 2860, 1552, 1478, 1438 cm–1.
1H NMR (400 MHz, CDCl3): d = 7.39–7.37 (m, 1 H, Harom), 7.29–
7.12 (m, 8 H, Harom), 4.74–4.69 (m, 1 H, CH2), 4.61–4.57 (m, 1 H,
CH2), 4.39–4.35 (m, 1 H, CH), 3.13–3.07 (m, 1 H, CH2), 2.97–2.92
(m, 1 H, CH2).
13C NMR (100 MHz, CDCl3): d = 137.4, 136.4, 134.0, 130.2, 129.1,
128.6, 127.8, 127.2, 126.9, 77.4, 41.8, 38.4.
1-Nitro-2,3-diphenylpropane (3a)
Yellow oil.16a
IR (KBr): 3063, 3030, 2923, 2825, 1601, 1551, 1496, 1500 cm–1.
1H NMR (400 MHz, CDCl3): d = 7.47–7.04 (m, 10 H, Harom), 4.65–
4.52 (m, 2 H, CH2), 3.81–3.74 (m, 1 H, CH), 3.07–2.93 (m, 2 H,
CH2).
MS (EI, 70 eV): m/z = 275 (M+), 245, 227, 214, 178, 138, 91, 77.
13C NMR (100 MHz, CDCl3): d = 139.0, 137.7, 129.0, 128.8, 128.6,
2-(2,4-Dichlorophenyl)-1-nitro-3-phenylpropane (3g)
White solid; mp 69 °C.
IR (KBr): 3079, 3025, 2957, 2916, 1587, 1549, 14734, 1442 cm–1.
127.7, 127.5, 126.8, 79.5, 46.0, 40.0.
MS (EI, 70 eV): m/z = 241 (M+), 211, 104, 91, 77.
1H NMR (400 MHz, CDCl3): d = 7.41–7.40 (s, 1 H, Harom), 7.30–
7.21 (m, 4 H, Harom), 7.11 (d, J = 8.0 Hz, 3 H, Harom), 4.71–4.57 (m,
2 H, CH2), 4.36–4.29 (m, 1 H, CH), 3.09–2.92 (m, 2 H, CH2).
13C NMR (100 MHz, CDCl3): d = 138.6, 137.2, 135.8, 133.9, 130.5,
129.9, 129.2, 128.4, 127.5, 78.7, 42.2, 39.2.
2-(4-Chlorophenyl)-1-nitro-3-phenylpropane (3b)
Pale yellow solid; mp 105–107 °C (Lit.16a 104–106 °C).
IR (KBr): 3027, 2915, 2858, 1549, 1487, 1435 cm–1.
1H NMR (400 MHz, CDCl3): d = 7.29–7.21 (m, 5 H, Harom), 7.10–
7.04 (m, 4 H, Harom), 4.58 (d, J = 8.0 Hz, 2 H, CH2), 3.77–3.73 (m,
1 H, CH), 2.96 (dd, J = 8.0, 4.4 Hz, 2 H, CH2).
MS (EI, 70 eV): m/z = 309 (M+), 263, 248, 178, 91, 75.
13C NMR (100 MHz, CDCl3): d = 137.5, 137.3, 133.5, 129.0, 129.0,
128.8, 128.7, 126.9, 79.3, 45.4, 40.0.
Anal. Calcd for C15H13Cl2NO2: C, 58.08; H, 4.22; N, 4.52. Found:
C, 58.00; H, 4.56; N, 4.08.
MS (EI, 70 eV): m/z = 275 (M+), 244, 228, 214, 178, 138, 91, 77.
2-(3,4-Dimethoxyphenyl)-1-nitro-3-phenylpropane (3h)
White solid; mp 75–77 °C.
2-(4-Methoxyphenyl)-1-nitro-3-phenylpropane (3c)
White solid; mp 81 °C (Lit.16b 78–79 °C).
IR (KBr): 3056, 3005, 2939, 2837, 1593, 1548, 1517, 1460, 1425
cm–1.
IR (KBr): 3020, 2921, 2841, 1550, 1511, 1438 cm–1.
1H NMR (400 MHz, CDCl3): d = 7.27–7.18 (m, 3 H, Harom), 7.07–
7.05 (m, 2 H, Harom), 6.81–6.73 (m, 1 H, Harom), 6.70 (d, J = 8.0 Hz,
1 H, Harom), 6.58 (s, 1 H, Harom), 4.57 (d, J = 6.8 Hz, 2 H, CH2), 3.85
(s, 3 H, OCH3), 3.81 (s, 3 H, OCH3), 3.72–3.69 (m, 1 H, CH), 3.03–
2.91 (m, 2 H, CH2).
13C NMR (100 MHz, CDCl3): d = 148.9, 148.4, 137.8, 131.4, 129.1,
128.5, 126.7, 119.3, 111.3, 110.8, 79.7, 55.9, 55.8, 45.6, 40.1.
1H NMR (400 MHz, CDCl3): d = 7.28–7.18 (m, 3 H, Harom), 7.09–
7.06 (m, 4 H, Harom), 6.83 (d, J = 8.8 Hz, 2 H, Harom), 4.56 (d, J = 7.2
Hz, 2 H, CH2), 3.78 (s, 3 H, OCH3), 3.75–3.69 (m, 1 H, CH), 3.08–
2.90 (m, 2 H, CH2).
13C NMR (100 MHz, CDCl3): d = 158.9, 137.9, 130.9, 129.0, 128.5,
128.5, 126.7, 114.2, 79.8, 55.2, 45.3, 40.1.
MS (EI, 70 eV): m/z = 271 (M+), 224, 180, 134, 91, 77.
MS (EI, 70 eV): m/z = 301 (M+), 255, 241, 210, 165, 91, 77.
Anal. Calcd for C17H19NO4: C, 67.76; H, 6.36; N, 4.65. Found: C,
67.59; H, 6.58; N, 4.34.
2-(4-Methylphenyl)-1-nitro-3-phenylpropane (3d)
White solid; mp 33 °C.
IR (KBr): 3024, 2932, 2856, 1549, 1444, 1381 cm–1.
2-(3-Bromophenyl)-1-nitro-3-phenylpropane (3i)
White solid; mp 35–36 °C.
IR (KBr): 3060, 3028, 2918, 2855, 1595, 1549, 1478, 1434 cm–1.
1H NMR (400 MHz, CDCl3): d = 7.41–7.39 (m, 1 H, Harom), 7.33–
7.28 (m, 1 H, Harom), 7.26–7.16 (m, 4 H, Harom), 7.07 (d, J = 6.4 Hz,
3 H, Harom), 4.59–4.55 (m, 2 H, CH2), 3.76–3.72 (m, 1 H, CH), 3.03–
2.90 (m, 2 H, CH2).
1H NMR (400 MHz, CDCl3): d = 7.29–7.20 (m, 3 H, Harom), 7.13–
7.05 (m, 6 H, Harom), 4.60–4.55 (m, 2 H, CH2), 3.76–3.72 (m, 1 H,
CH), 3.05–2.91 (m, 2 H, CH2), 2.32 (s, 3 H, CH3).
13C NMR (100 MHz, CDCl3): d = 137.9, 137.3, 136.0, 129.5, 129.0,
128.5, 127.3, 126.7, 79.7, 45.6, 40.0, 21.0.
MS (EI, 70 eV): m/z = 255 (M+), 208, 194, 118, 105, 91, 77.
Anal. Calcd for C16H17NO2: C, 75.27; H, 6.71; N, 5.49. Found: C,
75.58; H, 7.05; N, 5.06.
13C NMR (100 MHz, CDCl3): d = 141.4, 137.2, 130.9, 130.5, 130.4,
129.0, 128.7, 127.0, 126.2, 122.9, 79.1, 45.5, 39.8.
MS (EI, 70 eV): m/z = 319 (M+), 271, 258, 192, 91, 77.
2-(2-Methoxyphenyl)-1-nitro-3-phenylpropane (3e)
Yellow oil.16b
Anal. Calcd for C15H14BrNO2: C, 56.27; H, 4.41; N, 4.37. Found: C,
56.23; H, 4.70; N, 3.90.
IR (KBr): 3067, 3026, 2936, 2841, 1551, 1493, 1458 cm–1.
1H NMR (400 MHz, CDCl3): d = 7.25–7.22 (m, 4 H, Harom), 7.21–
7.01 (m, 3 H, Harom), 6.83 (d, J = 8.0 Hz, 2 H, Harom), 4.76 (q, J = 7.6
Hz, 1 H, CH2), 4.61 (q, J = 7.2 Hz, 1 H, CH2), 4.05–4.08 (m, 1 H,
CH), 3.83 (s, 3 H, OCH3), 3.11–2.97 (m, 2 H, CH2).
13C NMR (100 MHz, CDCl3): d = 157.5, 138.6, 129.1, 128.9, 128.6,
128.4, 126.9, 126.5, 120.7, 110.9, 77.9, 55.3, 41.6, 37.8.
2-(2-Furyl)-1-nitro-3-phenylpropane (3j)
Yellow oil.16b
IR (KBr): 3063, 3030, 2924, 2860, 1551, 1501, 1451, 1431 cm–1.
1H NMR (400 MHz, CDCl3): d = 7.37 (dd, J = 2.0, 0.8 Hz, 1 H,
Harom), 7.30–7.20 (m, 3 H, Harom), 7.08–7.06 (m, 2 H, Harom), 6.27–
6.26 (m, 1 H, Harom), 6.04 (d, J = 2.4 Hz, 1 H, Harom), 4.61 (dd,
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W. Shi, J.-X. Wang
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J = 12.8, 8 Hz, 1 H, CH2), 4.52 (dd, J = 12.8, 6.4 Hz, 1 H, CH2),
3.92–3.85 (m, 1 H, CH), 3.11 (dd, J = 13.6, 7.6 Hz, 1 H, CH2), 2.94
(dd, J = 13.6, 7.6 Hz, 1 H, CH2).
13C NMR (100 MHz, CDCl3): d = 151.9, 142.2, 137.4, 129.0, 128.6,
127.0, 110.4, 107.5, 77.3, 39.6, 37.3.
IR (KBr): 3030, 2921, 1558, 1487, 1438, 1384 cm–1.
1H NMR (400 MHz, CDCl3): d = 7.36–7.24 (m, 5 H, Harom), 7.11 (d,
J = 6.8 Hz, 2 H, Harom), 6.90 (d, J = 8.4 Hz, 2 H, Harom), 4.60 (d,
J = 7.2 Hz, 2 H, CH2), 3.75–3.68 (m, 1 H, CH), 2.94 (d, J = 8.0 Hz,
2 H, CH2).
MS (EI, 70 eV): m/z = 231 (M+), 184, 91, 77.
13C NMR (100 MHz, CDCl3): d = 138.4, 136.7, 131.6, 130.7, 128.9,
127.8, 127.5, 120.6, 79.5, 45.8, 39.2.
1-Nitro-3-phenyl-2-(2-thienyl)propane (3k)
MS (EI, 70 eV): m/z = 319 (M+), 273, 259, 169, 104, 90, 77.
Yellow oil.16b
Anal. Calcd for C15H14BrNO2: C, 56.27; H, 4.41; N, 4.37. Found: C,
56.23; H, 4.73; N, 4.03.
IR (KBr): 3029, 2922, 1551, 1433 cm–1.
1H NMR (400 MHz, CDCl3): d = 7.30–7.20 (m, 4 H, Harom), 7.12 (d,
J = 6.8 Hz, 2 H, Harom), 6.91 (dd, J = 4.8, 3.6 Hz, 1 H, Harom), 6.81
(d, J = 3.6 Hz, 1 H, Harom), 4.56 (m, J = 7.2 Hz, 2 H, CH2), 4.14–
4.06 (m, 1 H, CH), 3.10 (dd, J = 13.6, 7.2 Hz, 1 H, CH2), 3.00 (dd,
J = 13.6, 7.2 Hz, 1 H, CH2).
13C NMR (100 MHz, CDCl3): d = 141.9, 137.4, 129.0, 128.6, 127.0,
127.0, 125.5, 124.5, 80.0, 41.3, 40.8.
1-(4-Bromophenyl)-2-(4-chlorophenyl)-3-nitropropane (3p)
White solid; mp 86–87 °C.
IR (KBr): 3025, 2922, 1550, 1487, 1430, 1380 cm–1.
1H NMR (400 MHz, CDCl3): d = 7.37 (d, J = 2.0 Hz, 2 H, Harom),
7.36 (d, J = 2.0 Hz, 2 H, Harom), 7.04 (d, J = 7.2 Hz, 2 H, Harom), 6.89
(d, J = 8.0 Hz, 2 H, Harom), 4.57 (d, J = 7.2 Hz, 2 H, CH2), 3.72–3.69
(m, 1 H, CH), 2.95–2.88 (m, 2 H, CH2).
MS (EI, 70 eV): m/z = 247 (M+), 200, 110, 91, 77, 65.
13C NMR (100 MHz, CDCl3): d = 136.9, 136.3, 133.7, 131.7, 130.7,
1-(4-Chlorophenyl)-3-nitro-2-phenylpropane (3l)
129.1, 128.9, 79.2, 45.2, 39.1.
Pale yellow solid; mp 54–55 °C (Lit.16b 50–52 °C).
MS (EI, 70 eV): m/z = 355 (M+ + 2), 293, 178, 169, 103, 90, 77.
IR (KBr): 3030, 2922, 2857, 1555, 1489, 1450 cm–1.
Anal. Calcd for C15H13BrClNO2: C, 50.80; H, 3.69; N, 3.95. Found:
C, 51.00; H, 4.18; N, 3.52.
1H NMR (400 MHz, CDCl3): d = 7.32–7.26 (m, 3 H, Harom), 7.21 (d,
J = 4.8 Hz, 2 H, Harom), 7.20–7.10 (m, 2 H, Harom), 6.95 (d, J = 8.4
Hz, 2 H, Harom), 4.64–4.57 (m, 2 H, CH2), 3.75–3.68 (m, 1 H, CH),
2.96 (m, J = 8.0 Hz, 2 H, CH2).
13C NMR (100 MHz, CDCl3): d = 138.4, 136.2, 132.6, 130.4, 128.9,
128.6, 127.8, 127.5, 79.5, 45.9, 39.1.
Acknowledgment
The work was supported by the National Natural Science Founda-
tion of China (Grant 20272047, 20572086), the Gansu Natural
Science Foundation of China (0308RJZA-100) and Key Laboratory
of Eco-Environment-Related Polymer Material (Northwest Normal
University), Ministry of the Education of China.
MS (EI, 70 eV): m/z = 275 (M+), 244, 227, 214, 178, 125, 104, 91,
77.
1-(4-Chlorophenyl)-2-(4-methoxyphenyl)-3-nitropropane (3m)
White solid; mp 82–84 °C.
IR (KBr): 3038, 2927, 2846, 1611, 1547, 1436 cm–1.
References
1H NMR (400 MHz, CDCl3): d = 7.19 (d, J = 8.8 Hz, 2 H, Harom),
7.02 (d, J = 6.4 Hz, 2 H, Harom), 6.95 (d, J = 8.4 Hz, 2 H, Harom), 6.82
(d, J = 6.8 Hz, 2 H, Harom), 4.56 (d, J = 8.0 Hz, 2 H, CH2), 3.77 (s, 3
H, OCH3), 3.68–3.64 (m, 1 H, CH), 2.93 (d, J = 6.4 Hz, 2 H, CH2).
13C NMR (100 MHz, CDCl3): d = 159.0, 136.3, 132.5, 130.4, 130.3,
128.6, 128.5, 114.3, 79.8, 55.2, 45.2, 39.2.
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Georg Thieme Verlag: Stuttgart, 1995, 2041. (b) Ramkus,
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1545.
MS (EI, 70 eV): m/z = 305 (M+), 180, 134, 125, 91, 89.
(3) (a) Perekalin, V. V.; Lipina, E. S.; Berestovitskaya, V. M.;
Efremov, D. A. Nitroalkenes, Conjugated Nitro
Anal. Calcd for C16H16ClNO3: C, 62.85; H, 5.27; N, 4.58. Found: C,
62.90; H, 5.61; N, 4.16.
Compounds; John Wiley: Chichester, 1994, Chap. 2, 53.
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1-(4-Chlorophenyl)-2-(4-methylphenyl)-3-nitropropane (3n)
White solid; mp 79–80 °C.
IR (KBr): 3022, 2923, 2859, 1551, 1488, 1435 cm–1.
1H NMR (400 MHz, CDCl3): d = 7.19 (d, J = 8.4 Hz, 2 H, Harom),
7.09 (d, J = 7.6 Hz, 2 H, Harom), 7.10–6.94 (m, 4 H, Harom), 4.56 (d,
J = 6.8 Hz, 2 H, CH2), 3.70–3.65 (m, 1 H, CH), 2.93 (d, J = 7.2 Hz,
2 H, CH2), 2.30 (s, 3 H, CH3).
13C NMR (100 MHz, CDCl3): d = 137.5, 136.3, 135.3, 132.5, 130.4,
129.6, 128.6, 127.3, 79.7, 45.5, 39.1, 21.0.
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1996, 37, 6339. (b) Yao, C.-F.; Kao, K.-H.; Liu, J.-T.; Chu,
C.-M.; Wang, Y. Tetrahedron 1998, 54, 791.
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MS (EI, 70 eV): m/z = 289 (M+), 242, 228, 125, 118, 105, 89.
Anal. Calcd for C16H16ClNO2: C, 66.32; H, 6.14; N, 3.97. Found: C,
66.08; H, 6.03; N, 4.15.
1-(4-Bromophenyl)-3-nitro-2-phenylpropane (3o)
White solid; mp 60 °C.
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Synthesis 2009, No. 4, 597–601 © Thieme Stuttgart · New York