H. Ma et al. / Tetrahedron 68 (2012) 8358e8366
8365
CH2Cl2 (4.0 mL) in a round-bottomed flask was stirred at room
temperature for 18 h. The mixture was subjected to silica gel column
chromatography using a mixture eluent of petroleum ether and
ethyl acetate (1:5 in volume) to afford 13b as yellow solid (34 mg,
65%), Rf¼0.37 (petroleum ether/ethyl acetate¼1:2 in volume); mp
(0.15 equiv, 0.075 mmol, 19 mg), CH3COOOH (400
m
L) in CH2Cl2
(4.0 mL) in a round-bottomed flask was stirred at room temperature
for 24 h. The mixture was subjected to silica gel column chroma-
tography using a mixture eluent of petroleum ether and ethyl acetate
(100:1 in volume) to afford 19b as yellow solid (18 mg, 26%), Rf¼0.33
(petroleum ether/ethyl acetate¼100:1 in volume); mp 119e122 ꢀC;
211e214 ꢀC; 1H NMR (400 MHz, CDCl3):
d¼7.74 (d, J¼2.2 Hz, 4H),
6.75e6.72 (m, 4H), 3.94 (s, 4H); 13C NMR (100 MHz, CDCl3):
¼148.47, 145.79, 124.33, 114.75.
1H NMR (400 MHz, CDCl3):
d
¼8.06e8.04 (m, 2H), 7.90 (m, 2H),
d
7.63e7.61 (m, 2H), 7.51e7.42 (m, 2H), 3.15 (s, 1H); 13C NMR
(100 MHz, CDCl3):
d
¼134.73, 133.93, 130.47, 129.18, 126.39, 124.66,
4.4.15. 1,2-Bis(2,30-dimethyl-40-amidodiphenyl)diazene (15b). Accor-
ding to the general procedure 4.2.3, a mixture of 15a (0.5 mmol,
106 mg) and polymer supported-IBA (20 mg), CH3COOOH (450 mL) in
123.68, 123.19, 123.13, 123.11, 82.70, 78.10; HRMS (ESI) Calcd for
C14H9BrN2: 283.9949 [MþH]þ; found: 283. 9943 [MþH]þ.
CH2Cl2 (4.0 mL) in a round-bottomed flask was stirred at room tem-
perature for 15 h. The mixture was subjected to silica gel column
chromatography using a mixture eluent of petroleum ether and ethyl
acetate (5:1 in volume) to afford 15b as red solid (82 mg, 95%), Rf¼0.43
(petroleum ether/ethyl acetate¼4:1 in volume); mp 201e203 ꢀC; 1H
4.4.20. 1-(3-Ethynylphenyl)-2-(4-fluorophenyl)diazene (20b). A mix-
ture of 13a (0.25 mmol, 29.5 mg), 8a (0.5 mmol, 55.5 mg) and IBA
(0.15 equiv, 0.075 mmol, 19 mg), CH3COOOH (400
mL) in CH2Cl2
(4.0 mL) in a round-bottomed flask was stirred at room temperature
for 20 h. The mixture was subjected to silica gel column chromatog-
raphy using a mixture eluent of petroleum ether and ethyl acetate
(100:1 in volume) to afford 20b as yellow solid (26 mg, 48%), Rf¼0.34
(petroleum ether/ethyl acetate¼100:1 in volume); mp 92e94 ꢀC; 1H
NMR (400 MHz, CDCl3):
d¼7.71 (d, J¼8.4 Hz, 2H), 7.52 (s, 2H),
7.46e7.44 (m, 2H), 7.39e7.36 (m, 4H), 6.76 (d, J¼8 Hz, 2H), 3.73 (s, 4H),
2.79 (s, 6H), 2.26 (s, 6H); 13C NMR (100 MHz, CDCl3):
143.49, 138.64, 130.93, 129.38, 129.03, 125.93, 124.57, 122.76, 116.42,
115.43, 18.16, 17.80; MS (FAB): m/z¼420.2 [MþH]þ; Anal. Calcd for
C28H28N4: C, 79.97; H, 6.71; N,13.32; found: C, 79.94; H, 6.75; N,13.36.
d
¼149.90,144.79,
NMR (400 MHz, CDCl3):
d
¼8.03 (s,1H), 7.97e7.93 (m, 3H), 7.59 (s,1H),
7.48 (s,1H), 7.23e7.19 (m, 2H), 3.15 (s,1H); 13C NMR (100 MHz, CDCl3):
d
¼213.94, 134.29, 130.98, 129.14, 128.94, 126.22, 125.08, 124.99,
123.92, 123.47, 123.14, 119.81, 116.23, 116.01, 82.84, 78.51; HRMS (ESI)
4.4.16. 1,2-Bis(4-amidophenyl)diazene (16b). According to the gen-
eral procedure 4.2.1, the mixture of 16a (0.5 mmol, 92 mg) and PIDA
(0.95 equiv, 0.48 mmol, 138 mg) in dry CH2Cl2 (4 mL) was stirred for
3 h, the crude reaction mixture was purified by column chroma-
tography (silica gel, petroleum ether/ethyl acetate¼8:1 in volume)
to afford 16b as yellow solid (59 mg, 65%), Rf¼0.42 (petroleum ether/
ethyl acetate¼5:1 in volume); mp 203e206 ꢀC; 1H NMR (400 MHz,
Calcd for C14H9FN2: 224.0750 [MþH]þ; found: 224.0757 [MþH]þ.
4.4.21. 1-(4-Chlorophenyl)-2-(3-ethynylphenyl)diazene (21b). A mix-
ture of 13a (0.25 mmol, 29.5 mg), 4a (0.5 mmol, 63.5 mg) and IBA
(0.15 equiv, 0.075 mmol, 19 mg), CH3COOOH (400
mL) in CH2Cl2
(4.0 mL) in a round-bottomed flask was stirred at room temperature
for 24 h. The mixture was subjected to silica gel column chroma-
tography using a mixture eluent of petroleum ether and ethyl acetate
(100:1 in volume) to afford 21b as yellow solid (15 mg, 25%), Rf¼0.34
(petroleum ether/ethyl acetate¼100:1 in volume); mp 138e140 ꢀC;
CDCl3):
d
¼7.83 (d, J¼9.2 Hz, 2H), 7.35e7.30 (m, 2H), 7.18 (d, J¼8.0 Hz,
2H), 7.11 (d, J¼8.0 Hz, 2H), 7.05e7.01 (m, 1H), 6.00 (s, 1H); 13C NMR
(100 MHz, CDCl3):
d¼142.3,141.8,139.6,129.8,123.8,119.3,118.5; MS
(FAB): m/z¼364.1 [MþH]þ; Anal. Calcd for C24H20N4: C, 79.10; H,
1H NMR (400 MHz, CDCl3):
d
¼8.04 (s, 1H), 7.89e7.87 (m, 3H),
5.53; N, 15.37; found: C, 79.12; H, 5.56; N, 15.38.
7.61e7.59 (m,1H), 7.51e7.49 (m, 3H), 3.15 (s,1H); 13C NMR (100 MHz,
CDCl3):
d
¼162.32, 146.82, 133.62, 129.03, 125.96, 124.92, 124.01,
4.4.17. 1,2-Bis(2-formylphenyl)diazene (17b). According to the gen-
eral procedure 4.2.2, a mixture of 17a (0.5 mmol, 68.5 mg) and IBA
(0.15 equiv, 0.075 mmol, 19 mg), CH3COOOH (400 mL) in CH2Cl2
123.26, 122.94, 114.23, 83.03, 77.70; HRMS (ESI) Calcd for C14H9ClN2:
240.0454 [MþH]þ; found: 240.0459 [MþH]þ.
(4.0 mL) in a round-bottomed flask was stirred at room tempera-
ture for 15 h. The mixture was subjected to silica gel column
chromatography using a mixture eluent of petroleum ether and
ethyl acetate (1:100 in volume) to afford 17b as white solid (64 mg,
95%), Rf¼0.32 (ethyl acetate); mp 152e154 ꢀC; 1H NMR (400 MHz,
4.4.22. 1-(3-Chlorophenyl)-2-(3-ethynylphenyl)diazene (22b). A mix-
ture of 13a (0.25 mmol, 29.5 mg), 3a (0.5 mmol, 63.5 mg) and IBA
(0.15 equiv, 0.075 mmol, 19 mg), CH3COOOH (400
mL) in CH2Cl2
(4.0 mL) in a round-bottomed flask was stirred at room temperature
for 20 h. The mixture was subjected to silica gel column chroma-
tography using a mixture eluent of petroleum ether and ethyl acetate
(100:1 in volume) to afford 22b as yellow solid (30 mg, 50%), Rf¼0.34
(petroleum ether/ethyl acetate¼100:1 in volume); mp 105e107 ꢀC;
CDCl3):
d
¼7.94 (d, J¼1.6 Hz, 2H), 7.32e7.26 (m, 2H), 6.69e6.66 (m,
4H); 13C NMR (100 MHz, CDCl3):
d
¼173.60, 151.08, 135.11, 132.10,
116.76, 116.44; Anal. Calcd for C14H10N2O4: C, 62.22; H, 3.73; N,
10.37; found: C, 62.23; H, 3.77; N, 10.38.
1H NMR (400 MHz, CDCl3):
d
¼8.05 (s, 1H), 7.91e7.86 (m, 3H), 7.61 (s,
1H), 7.51e7.46 (m, 3H), 3.15 (s, 1H); 13C NMR (100 MHz, CDCl3):
4.4.18. 1-(4-Bromophenyl)-2-(3-ethynylphenyl)diazene (18b). A mix-
ture of 13a (0.25 mmol, 29.5 mg), 7a (0.5 mmol, 86 mg) and IBA
d
¼153.21, 152.07, 135.19, 134.74, 131.37, 131.06, 130.19, 129.93, 129.20,
128.85, 127.66, 126.41, 124.37, 123.69, 123.21, 122.56, 121.84, 121.09,
120.00, 117.96, 82.72, 78.10; HRMS (ESI) Calcd for C14H9ClN2:
240.0454 [MþH]þ; found: 240.0455 [MþH]þ.
(0.15 equiv, 0.075 mmol, 19 mg), CH3COOOH (400
mL) in CH2Cl2
(4.0 mL) in a round-bottomed flask was stirred at room temperature
for 20 h. The mixture was subjected to silica gel column chroma-
tography using a mixture eluent of petroleum ether and ethyl acetate
(100:1 in volume) to afford 18b as yellow solid (46 mg, 65%), Rf¼0.34
(petroleum ether/ethyl acetate¼100:1 in volume); 1H NMR
4.4.23. 1-(3-Ethynylphenyl)-2-(4-methoxyphenyl)diazene (23b). A
mixture of 13a (0.25 mmol, 29.5 mg), 11a (0.5 mmol, 61.5 mg) and
IBA (0.15 equiv, 0.075 mmol, 19 mg), CH3COOOH (400 mL) in CH2Cl2
(400 MHz, CDCl3):
d
¼8.04 (s, 1H), 7.82e7.80 (m, 3H), 7.67e7.65 (m,
(4.0 mL) in a round-bottomed flask was stirred at room tempera-
ture for 20 h. The mixture was subjected to silica gel column
chromatography using a mixture eluent of petroleum ether and
ethyl acetate (100:1 in volume) to afford 23b as yellow solid (31 mg,
52%), Rf¼0.33 (petroleum ether/ethyl acetate¼100:1 in volume); 1H
3H), 7.50e7.48 (m, 1H), 3.15 (s, 1H); 13C NMR (100 MHz, CDCl3):
d
¼152.32,151.7,134.50,132.03,128.96,128.53,125.32,125.30,123.26,
123.07, 83.03, 77.70; HRMS (ESI) Calcd for C14H9BrN2: 283.9949
[MþH]þ; found: 283.9943 [MþH]þ.
NMR (400 MHz, CDCl3):
d¼8.01 (s, 1H), 7.95e7.86 (m, 3H),
4.4.19. 1-(3-Bromophenyl)-2-(3-ethynylphenyl)diazene (19b). A mix-
ture of 13a (0.25 mmol, 29.5 mg), 6a (0.5 mmol, 86 mg) and IBA
7.55e7.46 (m, 2H), 7.04e7.01 (m, 2H), 3.91e3.90 (s, 1H), 3.14 (s, 1H);
13C NMR (100 MHz, CDCl3):
¼162.34, 152.50, 146.85, 133.64,
d