The Journal of Organic Chemistry
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132 mg; yield 42%; mp 143−144 °C; 1H NMR (500 MHz, CDCl3) δ
1.64−1.60 (m, 2H), 1.71−1.70 (m, 4H), 3.30−3.28 (m, 4H), 6.93 (d,
2H, J = 8 Hz), 7.20 (d, 1H, J = 16 Hz), 7.55 (d, 2H, J = 8 Hz), 7.68−
7.65 (m, 1H), 7.75−7.71 (m, 1H), 7.80 (d, 1H, J = 16 Hz), 8.05−8.02
(m, 2H), 9.01 (s, 1H); 13C NMR and JMOD (125 MHz, CDCl3) δ
152.5 (C), 151.5 (C), 144.6 (CH), 142.6 (C), 141.2 (C), 136.6 (CH),
130.2 (CH), 129.1 (CH), 129.0 (CH), 128.9 (CH),128.7 (CH), 126.0
(C), 121.5 (CH), 115.3 (CH), 49.5 (CH2), 25.6 (CH2), 24.4 (CH2).
Anal. Calcd for C21H21N3: C, 79.97; H, 6.71; N, 13.32. Found: C,
80.19; H, 6.67; N, 13.12.
(CH), 124.0 (C), 123.3 (CH), 120.3 (CH), 112.1 (CH), 40.3 (CH3).
Anal. Calcd for C14H15N3: C, 74.64; H, 6.71; N, 18.65. Found: C,
74.55; H, 6.73; N, 18.58.
General Procedure for Suzuki Cross-Coupling Reactions. A
stirred mixture of bromo derivative (0.5 mmol), arylboronic acid (1
mmol), Pd(PPh3)4 (0.025 mmol), aqueous 1 M sodium carbonate (1
mmol, 1 mL), and ethanol (1 mL) in degassed toluene (10 mL) was
heated under nitrogen for 15 h. The reaction mixture was cooled,
filtered, and dissolved with a mixture of EtAcO and water 1:1 (50 mL)
and the organic layer separated. The aqueous layer was extracted with
EtAcO (2 × 25 mL). The combined organic extracts were dried with
MgSO4 and the solvents evaporated.
4-[2-(4′-N,N-Dimethylamino-biphenyl-4-yl)-vinyl]-pyrimidine
(9a): Yellow solid; purified by recrystallization from CHCl3; 114 mg;
yield 76%; mp > 250 °C; 1H NMR (500 MHz, CDCl3) δ 3.01 (s, 6H),
6.81 (d, 2H, J = 8 Hz), 7.06 (d, 1H, J = 16 Hz), 7.31 (d, 1H, J = 5 Hz),
7.55 (d, 2H, J = 8 Hz), 7.61 (d, 2H, J = 8 Hz), 7.62 (d, 2H, J = 8 Hz),
7.91 (d, 1H, J = 16 Hz), 8.66 (d, 1H, J = 5 Hz), 9.16 (s, 1H); 13C
NMR and JMOD (125 MHz, CDCl3) δ 162.5 (C), 158.9 (CH), 157.3
(CH), 150.3 (C), 142.4 (C), 137.4 (CH), 133.2 (C), 128.2 (CH),
128.0 (C), 127.6 (CH), 126.4 (CH), 124.6 (CH), 118.6 (CH), 112.7
(CH). Anal. Calcd for C20H19N3: C, 79.70; H, 6.35; N, 13.94. Found:
C, 79.70; H, 6.36; N, 14.02.
2-[2-(4-N,N-Diphenylamino-phenyl)-vinyl]-quinoxaline (4f): Yel-
low solid; purified by column chromatography (SiO2, CH2Cl2); 180
1
mg; yield 45%; mp 115−116 °C; H NMR (500 MHz, CDCl3) δ
7.11−7.07 (m, 4H), 7.15 (dd, 4H, J1 = 8.5 Hz, J2 = 1.5 Hz), 7.27 (d,
1H, J = 16 Hz), 7.30 (dd, 4H, J1 = 8 Hz, J2 = 8.5 Hz), 7.52 (d, 2H, J =
8 Hz), 7.70−7.67 (m, 1H), 7.76−7.73 (m, 1H), 7.81 (d, 1H, J = 16
Hz), 8.05−8.03 (m, 2H), 9.02 (s, 1H); 13C NMR and JMOD (125
MHz, CDCl3) δ 151.1 (C), 149.0 (C), 147.2 (C), 144.5 (CH), 142.6
(C), 141.4 (C), 136.0 (CH), 130.3 (CH), 129.5 (CH), 129.2 (CH),
129.1 (CH), 129.0 (CH), 128.5 (CH), 125.2 (CH), 123.7 (CH),
123.1 (CH), 122.4 (CH). Anal. Calcd for C28H21N3: C, 84.18; H, 5.30;
N, 10.52. Found: C, 84.50; H, 5.26; N, 10.23.
2-(Ferrocenyl-vinyl)-quinoxaline (4g): Red solid; purified by
crystallization from a mixture of CH2Cl2/n-heptane; 153 mg; yield
45%; mp 137−138 °C; H NMR (500 MHz, CDCl3) δ 4.19 (s, 5H),
4-[2-(4′-N,N-Diphenylamino-biphenyl-4-yl)-vinyl]-pyrimidine
1
(9b): Yellow solid; purified by crystallization from a mixture of
1
CH2Cl2/n-heptane; 187 mg; yield 88%; mp 125−126 °C; H NMR
4.42 (s, 2H), 4.62 (s, 2H), 6.97 (d, 1H, J = 16 Hz), 7.73−7.67 (m,
2H), 7.72 (d, 1H, J = 16 Hz), 8.08−8.05 (m, 2H), 8.97 (s, 1H); 13C
NMR and JMOD (125 MHz, CDCl3) δ 151.0 (C), 144.1 (CH), 142.6
(C), 141.2 (C), 136.7 (CH), 130.2 (CH), 129.2 (CH), 128.9 (CH),
128.7 (CH), 122.8 (CH), 82.2 (C), 70.4 (CH), 69.6 (CH), 68.0
(CH). Anal. Calcd for C20H16FeN2: C, 70.61; H, 4.74; N, 8.23. Found:
C, 70.37; H, 4.69; N, 8.00.
(500 MHz, CDCl3) δ 7.05 (d, 1H, J = 16 Hz), 7.06 (d, 2H, J = 8 Hz),
7.11 (t, 2H, J = 7 Hz), 7.14 (d, 4H, J = 7.5 Hz), 7.29−7.26 (m, 4H),
7.32 (d, 1H, J = 5 Hz), 7.50 (d, 2H, J = 8 Hz), 7.62 (d, 2H, J = 8 Hz),
7.65 (d, 2H, J = 8 Hz), 7.92 (d, 1H, J = 16 Hz), 8.67 (d, 1H, J = 5 Hz),
9.17 (s, 1H); 13C NMR and JMOD (125 MHz, CDCl3) δ 162.3 (C),
158.9 (CH), 157.4 (CH), 147.7 (C), 147.5 (C), 141.7 (C), 137.2
(CH), 134.0 (C), 133.8 (C), 129.4 (CH), 128.2 (CH), 127.6 (CH),
126.9 (C), 125.1 (CH), 124.6 (CH), 123.6 (CH), 123.2 (CH), 118.7
(CH). Anal. Calcd for C30H23N3: C, 84.68; H, 5.45; N, 9.87. Found:
C, 84.86; H, 5.79; N, 9.51.
General Procedure for the Synthesis of 2-Arylvinylpyrazines
and 3-Arylvinylpyridazines. A stirred mixture of methyldiazine
(282 mg, 3 mmol) and KButO (448 mg, 4 mmol) and the
corresponding aldehyde (2 mmol) in refluxing THF (20 mL) was
heated under reflux for 2 h under nitrogen. The mixture was allowed
to cool, water was added, and the THF was evaporated under vacuum.
The mixture was then extracted with EtAcO (3 × 25 mL) and dried
(MgSO4) and the solvent evaporated.
4-[2-(4′-N,N-Methoxy-biphenyl-4-yl)-vinyl]-pyrimidine (9c): Beige
solid; purified by recrystallization from CHCl3/n-heptane; 84 mg;
1
yield 58%; mp 215−216 °C; H NMR (500 MHz, CDCl3) δ 3.86 (s,
3H), 6.99 (d, 2H, J = 8 Hz), 7.08 (d, 1H, J = 16 Hz), 7.32 (d, 1H, J = 5
Hz), 7.57 (d, 2H, J = 8 Hz), 7.60 (d, 2H, J = 8 Hz), 7.65 (d, 2H, J = 8
Hz), 7.92 (d, 1H, J = 16 Hz), 8.68 (s br, 1H), 9.17 (s, 1H); 13C NMR
and JMOD (125 MHz, CDCl3) δ 162.3 (C), 159.6 (C), 158.9 (CH),
157.4 (CH), 141.9 (C), 137.2 (CH), 133.9 (C), 132.8 (C), 128.2
(CH), 128.1 (CH), 127.1 (CH), 125.1 (CH), 118.7 (CH), 114.4
(CH). Anal. Calcd for C19H18N2O: C, 78.59; H, 6.25; N, 9.65. Found:
C, 78.63; H, 6.16; N, 9.49.
2-[2-(4-N,N-Dimethylamino-phenyl)-vinyl]-pyrazine (6a): Yellow
solid; purified by column chromatography (SiO2, EtOAc/petroleum
ether, 3:7); 117 mg; yield 26%; mp 117−118 °C; 1H NMR (500 MHz,
CDCl3) δ 3.03 (s, 6H), 6.72 (d, 2H, J = 8 Hz), 6.94 (d, 1H, J = 16
Hz), 7.49 (d, 2H, J = 8 Hz), 7.67 (d, 1H, J = 16 Hz), 8.31 (d, 1H, J = 3
Hz), 8.48 (dd, 1H, J1 = 3 Hz, J2 = 2 Hz), 8.58 (d, 1H, J = 2 Hz); 13
C
NMR and JMOD (125 MHz, CDCl3) δ 152.3 (C), 151.0 (C), 144.2
(CH), 143.4 (CH), 141.6 (CH), 135.5 (CH), 128.7 (CH), 124.2 (C),
119.3 (CH), 112.2 (CH), 40.3 (CH3). Anal. Calcd for C14H15N3: C,
74.64; H, 6.71; N, 18.65. Found: C, 74.87; H, 6.67; N, 18.86.
2-[2-(4-N,N-Diphenylamino-phenyl)-vinyl]-pyrazine (6b): Yellow
solid; purified by column chromatography (SiO2, EtOAc/petroleum
ether, 3:7); 237 mg; yield 34%; mp 135−136 °C; 1H NMR (500 MHz,
CDCl3) δ 7.03 (d, 1H, J = 16 Hz), 7.09−7.05 (m, 4H), 7.14 (dd, 4H,
J1 = 8.5 Hz, J2 = 1 Hz), 7.30−7.27 (m, 4H), 7.45 (d, 2H, J = 8 Hz),
7.68 (d, 1H, J = 16 Hz), 8.36 (d, 1H, J = 3 Hz), 8.51 (dd, 1H, J1 = 3
Hz, J2 = 2 Hz), 8.61 (d, 1H, J = 2 Hz); 13C NMR and JMOD (125
MHz, CDCl3) δ 151.7 (C), 148.7 (C), 147.2 (C), 144.3 (CH), 143.6
(CH), 142.25 (CH), 134.7 (CH), 129.6 (C), 129.4 (CH), 128.3
(CH), 125.0 (CH), 123.6 (CH), 122.6 (CH), 121.9 (CH). Anal.
Calcd for C24H19N3: C, 82.49; H, 5.48; N, 12.03. Found: C, 82.28; H,
5.67; N, 11.81.
2-[2-(4′-N,N-Dimethylamino-biphenyl-4-yl)-vinyl]-quinoxaline
(10a): Orange solid; purified by crystallization from a mixture of
1
CHCl3/n-heptane; 105 mg; yield 60%; mp 208−209 °C; H NMR
(500 MHz, CDCl3) δ 3.02 (s, 6H), 6.82 (d, 2H, J = 8 Hz), 7.40 (d,
1H, J = 16 Hz), 7.57 (d, 2H, J = 8 Hz), 7.64 (d, 2H, J = 8 Hz), 7.72−
7.69 (m, 3H), 7.78−7.75 (m, 1H), 7.91 (d, 1H, J = 16 Hz), 8.08−8.05
(m, 2H), 9.06 (s, 1H); 13C NMR and JMOD (125 MHz, CDCl3) δ
150.9 (C), 150.2 (C), 144.5 (CH), 142.5 (C), 142.1 (C), 141.5 (C),
136.3 (CH), 133.6 (C), 130.3 (CH), 129.2 (CH), 129.1 (CH), 128.1
(C), 128.0 (2 × CH), 127.6 (CH), 126.5 (CH), 124.4 (CH), 112.7
(CH), 40.5 (CH3); HRMS (ESI+, TOF) m/z calculated for C24H22N3
(MH+), 352.1814; found, 352.1814.
2-[2-(4′-N,N-Diphenylamino-biphenyl-4-yl)-vinyl]-quinoxaline
(10b): Yellow solid; purified by crystallization from a mixture of
1
CHCl3/n-heptane; 214 mg; yield 90%; mp 131−132 °C; H NMR
(500 MHz, CDCl3) δ 7−11−7.07 (m, 4H), 7.15 (dd, 4H, J1 = 8.5 Hz,
J2 = 1.5 Hz), 7.27 (d, 1H, J = 16 Hz), 7.30 (dd, 4H, J1 = 8 Hz, J2 = 8.5
Hz), 7.52 (d, 2H, J = 8 Hz), 7.57 (d, 2H, J = 8 Hz), 7.64 (d, 2H, J = 8
Hz), 7.70−7.67 (m, 1H), 7.76−7.73 (m, 1H), 7.91 (d, 1H, J = 16 Hz),
8.08−8.07 (m, 2H), 9.06 (s, 1H); 13C NMR and JMOD (125 MHz,
CDCl3) δ 150.8 (C), 147.64 (C), 147.56 (C), 144.5 (CH), 142.5 (C),
141.6 (C), 141.5 (C), 136.1 (CH), 134.5 (C), 133.9 (C), 132.2 (CH),
123.1 (CH), 129.4 (CH), 129.2 (CH), 128.6 (CH), 128.5 (CH),
3-[2-(4-N,N-Dimethylamino-phenyl)-vinyl]-pyridazine (8): Orange
solid; purified by column chromatography (SiO2, EtOAc); 220 mg;
yield 49%; mp 159−160 °C (lit.33 162 °C); H NMR (500 MHz,
1
CDCl3) δ 3.02 (s, 6H), 6.72 (d, 2H, J = 8 Hz), 7.15 (d, 1H, J = 16
Hz), 7.37 (dd, 1H, J1 = 8 Hz, J2 = 5 Hz), 7.50 (d, 2H, J = 8 Hz), 7.57
(dd, 1H, J1 = 8 Hz, J2 = 2 Hz), 7.60 (d, 1H, J = 16 Hz), 8.97 (dd, 1H,
J1 = 5 Hz, J2 = 2 Hz); 13C NMR and JMOD (125 MHz, CDCl3) δ
159.1 (C), 151.0 (C), 148.9 (CH), 135.4 (CH), 128.7 (CH), 126.2
4094
dx.doi.org/10.1021/jo3004919 | J. Org. Chem. 2012, 77, 4087−4096