Aminobromination of β-Nitrostyrene Derivatives
the reaction mixture and the addition of aqueous Na2SO3 before
the workup.
ArCH), 4.14 (s, 2 H, OCH2Me), 2.35 (s, 3 H, ArCH3), 1.25 (t, 3
H, OCH2CH3) ppm. 13C NMR (75.45 MHz, CDCl3): δ = 154.9,
139.8, 130.5, 129.3 (2), 128.8 (2), 94.2, 64.8, 62.1, 21.2, 14.4 ppm.
C12H14Br2N2O4 (410.06): calcd. C 35.15, H 3.44, N 6.83; found C
35.24, H 3.49, N 6.75.
2,2-Dibromo-1-[(ethyoxycarbonyl)amino]-2-nitro-1-phenylethane
(1b): White solid (1865 mg, 94% yield) obtained from β-nitrosty-
rene (1a, 745 mg. 5.0 mmol); m.p. 96–97 °C (EtOH). 1H NMR
(300 MHz, CDCl3): δ = 7.43–7.40 (m, 5 H, Ar), 6.02 (d, J = 9.9 Hz,
1 H, NH), 5.77 (s, 1 H, PhCH), 4.14 (s, 2 H, OCH2Me), 1.25 (t, 3
H, OCH2CH3) ppm. 13C NMR (75.45 MHz, CDCl3): δ = 154.4,
133.1, 129.2, 128.5 (2), 128.1 (2), 93.4, 64.5, 61.6, 13.9 ppm.
C11H12Br2N2O4 (391.03): calcd. C 33.36, H 3.05, N 7.07; found C
33.43, H 3.08, N 7.01.
2,2-Dibromo-1-(2-bromo-4,5-dimethoxyphenyl)-1-[(ethyoxycarbon-
yl)amino]-2-nitroethane (7b): White solid (2225 mg, 83% yield) ob-
1
tained from 7a (1440 mg. 5.0 mmol); m.p. 149–150 °C (EtOH). H
NMR (300 MHz, CDCl3): δ = 7.08 (s, 2 H, Ar), 6.66 (d, J = 9.6 Hz,
1 H, Ar), 5.79 (s, 1 H, ArCH), 4.13 (d, J = 6.0 Hz, 2 H, OCH2Me),
3.90 (s, 6 H, ArOCH3), 1.25 (s, 3 H, OCH2CH3) ppm. 13C NMR
(75.45 MHz, CDCl3): δ = 154.6, 150.5 (2), 148.7, 126.1, 115.7,
110.7, 93.3, 62.8, 62.2, 56.2 (2), 14.3 ppm. C13H15Br3N2O6 (534.98):
calcd. C 29.19, H 2.83, N 5.24; found C 29.30, H 2.88, N 5.19.
2,2-Dibromo-1-(4-bromophenyl)-1-[(ethyoxycarbonyl)amino]-2-nitro-
ethane (2b): White solid (2300 mg, 97% yield) obtained from 2a
(1140 mg, 5.0 mmol); m.p. 50–52 °C (EtOH). 1H NMR (300 MHz,
CDCl3): δ = 7.51 (d, J = 8.4 Hz, 2 H, Ar), 7.36 (d, J = 7.8 Hz, 2
H, Ar), 6.01 (s, 2 H, ArCH), 4.12 (d, J = 6.3 Hz, 2 H, OCH2Me),
1.23 (s, 3 H, OCH2CH3) ppm. 13C NMR (75.45 MHz, CDCl3): δ =
155.0, 132.7, 131.8 (2), 130.7 (2), 124.1, 93.3, 64.6, 62.3, 14.4 ppm.
C11H11Br3N2O4 (474.93): calcd. C 27.82, H 2.33, N 5.90; found C
27.93, H 2.38, N 5.85.
2,2-Dibromo-1-[(ethyoxycarbonyl)amino]-1-(4-methoxyphenyl)-2-
nitroethane (8b): Colorless oil (1879 mg, 88% yield) obtained from
1
8a (895 mg. 5.0 mmol). H NMR (300 MHz, CDCl3): δ = 7.39 (d,
J = 8.4 Hz, 2 H, Ar), 6.88 (d, J = 8.4 Hz, 2 H, Ar), 6.09 (s, 1 H,
NH), 5.99 (d, J = 9.3 Hz, 1 H, ArCH), 4.10 (t, 2 H, OCH2Me),
3.78 (s, 3 H, ArOCH3), 1.23 (t, 3 H, OCH2CH3) ppm. 13C NMR
(75.45 MHz, CDCl3): δ = 160.5, 155.2, 130.3 (2), 125.4, 113.9 (2),
94.7, 64.7, 62.0, 55.3, 13.9 ppm. C12H14Br2N2O5 (426.06): calcd. C
33.83, H 3.31, N 6.58; found C 33.91, H 3.36, N 6.55.
2,2-Dibromo-1-(4-chlorophenyl)-1-[(ethyoxycarbonyl)amino]-2-nitro-
ethane (3b): White solid (2063 mg, 96% yield) obtained from 3a
1
(918 mg. 5.0 mmol); m.p. 50–51 °C (EtOH). H NMR (300 MHz,
CDCl3): δ = 7.41 (d, J = 8.4 Hz, 2 H, Ar), 7.36 (d, J = 7.5 Hz, 2
H, Ar), 6.00 (d, J = 9.3 Hz, 1 H, NH), 5.78 (d, J = 9.3 Hz, 1 H,
2,2-Dibromo-1-[(ethyoxycarbonyl)amino]-2-nitro-1-(3,4,5-tri-
methoxyphenyl)ethane (9b): White solid (2041 mg, 84% yield) ob-
ArCH), 4.13 (t, 2 H, OCH2Me), 1.25 (t, 3 H, OCH2CH3) ppm. 13
C
1
tained from 9a (1195 mg. 5.0 mmol); m.p. 122–124 °C (EtOH). H
NMR (75.45 MHz, CDCl3): δ = 154.8, 135.9, 132.1, 130.4 (2),
128.8 (2), 93.3, 64.4, 62.3, 14.4 ppm. C11H11Br2ClN2O4 (430.48):
calcd. C 30.69, H 2.58, N 6.51; found C 30.75, H 2.62, N 6.45.
NMR (300 MHz, CDCl3): δ = 6.64 (s, 2 H, Ar), 5.93 (d, J = 9.0 Hz,
1 H, NH), 5.76 (d, J = 8.7 Hz, 1 H, ArCH), 4.16 (s, 2 H, OCH2Me),
3.87 (s, 9 H, ArOCH3), 1.27 (t, 3 H, OCH2CH3) ppm. 13C NMR
(75.45 MHz, CDCl3): δ = 155.0, 153.1 (2), 139.0, 128.7, 106.3 (2),
93.8, 65.2, 62.2, 60.9, 56.2 (2), 14.4 ppm. C14H18Br2N2O7 (486.11):
calcd. C 34.59, H 3.73, N 5.76; found C 34.67, H 3.76, N 5.70.
2,2-Dibromo-1-[(ethyoxycarbonyl)amino]-2-nitro-1-(4-nitrophenyl)-
ethane (4b) and Ethyl (4-Nitrobenzylidene)carbamate (d): The prod-
ucts were obtained from 4a (970 mg. 5.0 mmol). Data for 4b: White
solid (1968 mg, 89 % yield); m.p. 78–80 °C (EtOH). 1H NMR
(300 MHz, CDCl3): δ = 8.26 (d, J = 8.4 Hz, 2 H, Ar), 7.70 (d, J =
8.7 Hz, 2 H, Ar), 6.14 (d, J = 9.9 Hz, 1 H, NH), 5.79 (d, J = 9.9 Hz,
1 H, ArCH), 4.16 (d, J = 6.3 Hz, 2 H, OCH2Me), 1.25 (t, 3 H,
OCH2CH3) ppm. 13C NMR (75.45 MHz, CDCl3): δ = 154.7, 148.6,
140.5, 130.3 (2), 123.7 (2), 91.9, 64.3, 62.5, 14.4 ppm.
C11H11Br2N3O6 (441.03): calcd. C 29.96, H 2.51, N 9.53; found C
30.04, H 2.55, N 9.50. Data for d: White solid (78 mg, 7% yield);
m.p. 145–146 °C (EtOH). 1H NMR (300 MHz, CDCl3): δ = 8.43
(s, 1 H, Ar), 8.33 (d, J = 8.7 Hz, 2 H, Ar), 8.02 (d, J = 8.7 Hz, 2
H, Ar), 4.30 (d, J = 10.2 Hz, 2 H, OCH2Me), 1.34 (t, 3 H,
OCH2CH3) ppm. 13C NMR (75.45 MHz, CDCl3): δ = 164.1, 151.0,
150.3, 139.6, 129.0 (2), 123.9 (2), 62.9, 14.2 ppm. C10H10N2O4
(222.20): C 54.05, H 4.54, N 12.61; found C 54.16, H 4.58, N 12.56.
2,2-Dibromo-1-(4-bromo-3,5-dimethoxyphenyl)-1-[(ethyoxycarbon-
yl)amino]-2-nitroethane (10e) and 4-Bromo-3,5-dimethoxy-β-nitro-
styrene (10f): The products were obtained from 10a (1045 mg.
5.0 mmol). Data for 10e: White solid (1463 mg, 55% yield); m.p.
1
155–157 °C (EtOH). H NMR (300 MHz, CDCl3): δ = 6.89 (d, J
= 9.9 Hz, 1 H, Ar), 6.75 (s, 1 H, Ar), 6.54 (s, 1 H, Ar), 5.73 (s, 1
H, ArCH), 4.12 (d, J = 7.2 Hz, 2 H, OCH2Me), 3.90 (s, 3 H, Ar-
OCH3), 3.83 (s, 3 H, ArOCH3), 1.24 (t, 3 H, OCH2CH3) ppm. 13C
NMR (75.45 MHz, CDCl3): δ = 159.3, 156.5, 154.0, 135.8, 104.2
(2), 99.8, 92.1, 61.9, 56.0, 55.2 (2), 13.8 ppm. C13H15Br3N2O6
(543.98): calcd. C 29.19, H 2.83, N 5.24; found C 29.25, H 2.87, N
5.20. Data for 10f: Yellow solid (345 mg, 24% yield); m.p. 176–
177 °C (EtOH). 1H NMR (300 MHz, CDCl3): δ = 8.44 (d, J =
13.5 Hz, 1 H, Ar), 7.50 (d, J = 13.5 Hz, 1 H, Ar), 6.65 (s, 1 H,
=CHNO2), 6.60 (s, 1 H, CH=), 3.91 (s, 3 H, ArOCH3), 3.85 (s, 3
H, ArOCH3) ppm. 13C NMR (75.45 MHz, CDCl3): δ = 159.4,
157.1, 138.7, 137.7, 131.2, 103.4, 102.1, 56.0, 55.3 ppm.
C10H10BrNO4 (288.09): calcd. C 41.69, H 3.50, N 4.86; found C
41.70, H 3.53, N 4.85.
2,2-Dibromo-1-[(ethyoxycarbonyl)amino]-1-(3-methoxyphenyl)-2-
nitroethane (5b): White solid (2071 mg, 97% yield) obtained from
5a (895 mg. 5.0 mmol); m.p. 108–109 °C (EtOH). 1H NMR
(300 MHz, CDCl3): δ = 7.31 (d, J = 7.5 Hz, 1 H, Ar), 7.03–6.92
(m, 3 H, Ar), 5.98 (d, J = 9.6 Hz, 1 H, NH), 5.75 (d, J = 9.3 Hz,
1 H, ArCH), 4.15 (d, J = 4.2 Hz, 2 H, OCH2Me), 3.81 (s, 3 H,
ArOCH3), 1.25 (t, 3 H, OCH2CH3) ppm. 13C NMR (75.45 MHz,
CDCl3): δ = 159.5, 134.9, 129.6, 121.2 (2), 115.2, 114.8, 93.7, 65.0,
62.1, 55.4, 13.4 ppm. C12H14Br2N2O5 (426.06): C 33.83, H 3.31, N
6.58; found C 33.89, H 3.35, N 6.54.
2,2-Dibromo-1-[(ethyoxycarbonyl)amino]-1-(1-naphthalenyl)-2-nitro-
ethane (11b): Viscous yellowish oil (1781 mg, 80% yield) obtained
from 11a (995 mg. 5.0 mmol). 1H NMR (300 MHz, CDCl3): δ =
8.40 (d, J = 8.1 Hz, 1 H, Ar), 7.92–7.86 (m, 3 H, Ar), 7.52–7.50
(m, 3 H, Ar), 7.08 (d, J = 9.6 Hz, 1 H, Ar), 5.99 (d, J = 9.3 Hz, 1
2,2-Dibromo-1-[(ethyoxycarbonyl)amino]1-(4-methylphenyl)-2- H, ArCH), 4.05 (q, J = 6.3 Hz, 2 H, OCH2Me), 1.16 (t, 3 H,
nitroethane (6b): White solid (1911 mg, 93% yield) obtained from
6a (815 mg. 5.0 mmol); m.p. 40–42 °C (EtOH). 1H NMR
(300 MHz, CDCl3): δ = 7.32 (d, J = 7.2 Hz, 2 H, Ar), 7.18 (d, J =
7.5 Hz, 2 H, Ar), 5.97 (d, J = 9.6 Hz, 1 H, NH), 5.71 (s, 1 H,
OCH2CH3) ppm. 13C NMR (75.45 MHz, CDCl3): δ = 155.2, 133.7,
132.0, 131.3, 130.5, 129.0, 127.2, 126.3, 125.2, 124.9, 123.4, 94.0,
62.2, 58.5, 14.3 ppm. C15H14Br2N2O4 (446.09): calcd. C 40.39, H
3.16, N 6.28; found C 40.47, H 3.23, N 6.25.
Eur. J. Org. Chem. 2011, 5887–5893
© 2011 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjoc.org
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