4
Journal of Chemical Research 00(0)
chromatography was performed on Polygram SIL G/UV254 1-([4-bromophenyl]diazenyl)naphthalen-2-ol (3f):29 Red
plates. Visualization was accomplished with shortwave powder; yield 74%; m.p. 168–170°C (lit.32169–170°C); 1H
UV light, or by KMnO4 staining followed by heating. NMR (500MHz, Chloroform-d): δ 16.06 (s, 1H), 8.53 (d,
Flash column chromatography was performed using silica J=8.2Hz, 1H), 7.73 (d, J=9.4Hz, 1H), 7.62-7.54 (m, 6H),
gel (200300 mesh) from Qingdao Haiyang Chemical Co., 7.41 (t, J=7.0Hz, 1H), 6.86 (d, J=9.4Hz, 1H).
Ltd with solvents distilled prior to use.
1-({4-iodophenyl}diazenyl)naphthalen-2-ol (3g):33 Dark red
powder; yield 69%; m.p. 164–166°C; 1H NMR (500MHz,
General procedure for the synthesis of azo
Chloroform-d): δ 16.05 (s, 1H), 8.46 (d, J=8.1Hz, 1H),
compounds
7.74 (d, J=8.7Hz, 2H), 7.68 (d, J=9.4Hz, 1H), 7.56 (d,
To a solution of β-naphthol (1.0mmol, 1.0 equiv.) in DCM J=7.8Hz, 1H), 7.54-7.50 (m, 1H), 7.41 (d, J=8.7Hz, 2H),
(5.0mL) was added the aryl amine (1.5mmol, 1.5 equiv.) 7.38 (t, J=7.5Hz, 1H), 6.81 (d, J=9.4Hz, 1H); 13C NMR
and t-BuONO (1.5mmol, 1.5 equiv.). The reaction mixture (126MHz, Chloroform-d): δ 172.6, 144.5, 140.7, 138.7,
was stirred in air at room temperature for 24h and then con- 133.5, 130.4, 129.1, 128.8, 128.3, 126.1, 124.9, 121.9,
centrated in vacuum. The crude mixture was purified by 120.2, 91.8.
column chromatography on silica gel with a mixture of
petroleum ether and ethyl acetate as eluent to afford the 1-({4-methoxyphenyl}diazenyl)naphthalen-2-ol (3h):29 Red
target compounds.
powder; yield 80%; m.p. 136–138°C (lit.29137–138°C); 1H
NMR (500MHz, Chloroform-d): δ 15.72 (s, 1H), 8.70 (d,
1-(phenyldiazenyl)naphthalen-2-ol (3a):26 Red powder; J=8.3Hz, 1H), 7.82 (d, J=9.0Hz, 2H), 7.76 (d, J=9.2Hz,
1
yield 87%; m.p. 130–132°C (lit.26128–130°C); H NMR 1H), 7.69 (d, J=7.9Hz, 1H), 7.57 (t, J=7.7Hz, 1H), 7.40 (t,
(500MHz, Chloroform-d): δ 8.56 (d, J=8.2Hz, 1H), 7.76- J=7.5Hz, 1H), 7.03 (dd, J=10.4, 9.1Hz, 3H), 3.88 (s, 3H).
7.70 (m, 3H), 7.60 (d, J=7.8Hz, 1H), 7.55 (t, J=7.7Hz,
1H), 7.48 (t, J=7.9Hz, 2H), 7.39 (t, J=7.5Hz, 1H), 7.30 (t, Ethyl-4-({2-hydroxynaphthalen-1-yl}diazenyl)benzoate
J=7.4Hz, 1H), 6.87 (d, J=9.4Hz, 1H).
(3i): Redpowder;yield66%;m.p. 139–141°C(lit.34149°C);
1H NMR (500MHz, Chloroform-d): δ 8.43 (d, J=8.1Hz,
1-(p-tolyldiazenyl)naphthalen-2-ol (3b):29 Red powder; 1H), 8.12 (d, J=8.6Hz, 2H), 7.67-7.64 (m, 3H), 7.58-7.51
yield 88%; m.p. 132–133°C (lit.29130–132°C); H NMR (m, 2H), 7.40 (t, J=7.4Hz, 1H), 6.73 (d, J=9.6Hz, 1H),
1
(500MHz, Chloroform-d): δ 8.62 (d, J=8.3Hz, 1H), 7.73 4.41 (q, J=7.2Hz, 2H), 1.44 (t, J=7.1Hz, 3H); 13C NMR
(d, J=9.3Hz, 1H), 7.68 (d, J=8.3Hz, 2H), 7.63 (d, (126MHz, Chloroform-d): δ 178.0, 166.1, 146.8, 142.3,
J=7.9Hz, 1H), 7.56 (t, J=7.6Hz, 1H), 7.40 (t, J=7.5Hz, 133.5, 131.4, 131.1, 129.5, 129.0, 128.4, 127.8, 126.8,
1H), 7.29 (d, J=8.1Hz, 2H), 6.93 (d, J=9.3Hz, 1H), 2.42 126.2, 122.2, 116.9, 61.2, 14.5.
(s, 3H); 13C NMR (126MHz, Chloroform-d): δ 168.6,
143.7, 139.0, 138.5, 133.7, 130.3, 129.9, 128.7, 128.6, 1-({4-nitrophenyl}diazenyl)naphthalen-2-ol (3j):4 Red pow-
128.2, 125.5, 124.1, 121.8, 119.3, 21.4.
der; yield 86%; m.p. 250–252°C (lit.4249–250°C); 1H NMR
(500MHz, Chloroform-d): δ16.13 (s, 1H), 8.42 (d, J=8.0Hz,
1-({4-[tert-butyl]phenyl}diazenyl)naphthalen-2-ol (3c): Red 1H), 8.32 (d, J=9.1Hz, 2H), 7.71-7.68 (m, 3H), 7.60-7.51
solid; yield 92%; m.p. 87–89°C (lit.3186–88°C); 1H NMR (m, 2H), 7.44 (t, J=7.4Hz, 1H), 6.70 (d, J=9.6Hz, 1H).
(500MHz, Chloroform-d): δ 8.60 (d, J=8.3Hz, 1H), 7.73-
7.70 (m, 3H), 7.62 (d, J=7.8Hz, 1H), 7.56 (t, J=7.7Hz, 1-({3-(trifluoromethyl)phenyl}diazenyl)naphthalen-2-ol
1H), 7.51 (d, J=8.7Hz, 2H), 7.39 (t, J=6.9Hz, 1H), 6.92 (3k): Bright red powder; yield 88%; m.p. 159–160°C
1
(d, J=9.4Hz, 1H), 1.37 (s, 9H); 13C NMR (126MHz, Chlo- (lit.35193–195°C); H NMR (500MHz, Chloroform-d): δ
roform-d): δ 169.4, 151.6, 143.3, 139.2, 133.7, 130.0,128.8, 16.06 (s, 1H), 8.47 (d, J=8.5Hz, 1H), 7.93 (s, 1H), 7.79 (d,
128.7, 128.2, 126.7, 125.5, 124.4, 121.8, 119.0, 34.9, 31.5. J=8.0Hz, 1H), 7.69 (d, J=9.5Hz, 1H), 7.61-7.49 (m, 4H),
7.39 (t, J=7.4Hz, 1H), 6.80 (d, J=9.5Hz, 1H); 13C NMR
1-({4-fluorophenyl}diazenyl)naphthalen-2-ol (3d): Red floc- (126MHz, Chloroform-d): δ 173.9, 145.1, 141.4, 133.4,
1
cule; yield 90%; m.p. 144–146°C (lit.28143–145°C); H 132.3 (q, J=32.9Hz), 130.7, 130.3, 129.4, 128.9, 128.4,
NMR (500MHz, Chloroform-d): δ 15.80 (s, 1H), 8.57 (d, 126.5, 125.1, 123.9 (q, J=272.6Hz), 123.3 (q, J=3.6Hz),
J=8.2Hz, 1H), 7.77-7.70 (m, 3H), 7.62 (d, J=7.9Hz, 1H), 122.1, 121.4, 114.9 (q, J=4.0Hz).
7.54 (t, J=7.7Hz, 1H), 7.38 (t, J=6.9Hz, 1H), 7.16 (t,
J=8.6Hz, 2H), 6.93 (d, J=9.3Hz, 1H); 13C NMR (126MHz, 1-({3-nitrophenyl}diazenyl)naphthalen-2-ol (3l):32 Red pow-
1
Chloroform-d): δ 166.5, 162.5 (d, J=249.3Hz), 143.0 (d, der; yield 90%; m.p. 194–196°C (lit.32194–196°C); H
J=2.9Hz), 138.9, 133.5, 129.9, 128.7, 128.6, 128.3, 125.5, NMR (500MHz, Chloroform-d): δ 16.03 (s, 1H), 8.54 (s,
123.4, 121.7, 121.3 (d, J=8.5Hz), 116.6 (d, J=23.2Hz).
1H), 8.50 (d, J=8.2Hz, 1H), 8.08 (d, J=8.1Hz, 1H), 7.91
(d, J=8.0Hz, 1H), 7.73 (d, J=9.5Hz, 1H), 7.65-7.53 (m,
1-({4-chlorophenyl}diazenyl)naphthalen-2-ol (3e):26 Red 3H), 7.43 (t, J=7.4Hz, 1H), 6.80 (d, J=9.5Hz, 1H).
floccule; yield 64%; m.p. 153–155°C (lit.26158–160°C);
1H NMR (500MHz, Chloroform-d): δ 16.03 (s, 1H), 8.53 1-({2,4-dimethylphenyl}diazenyl)naphthalen-2-ol (3m):
(d, J=8.2Hz, 1H), 7.72 (d, J=9.4Hz, 1H), 7.67 (d, Dark red solid; yield 93%; m.p. 149–150°C (lit.36159–
1
J=8.9Hz, 2H), 7.60 (d, J=7.8Hz, 1H), 7.55 (t, J=7.7Hz, 160°C); H NMR (500MHz, Chloroform-d): δ 8.59 (d,
1H), 7.45-7.38 (m, 3H), 6.87 (d, J=9.4Hz, 1H).
J=8.2Hz, 1H), 7.94 (d, J=8.3Hz, 1H), 7.70 (d, J=9.4Hz,