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and the solution was stirred at 110–120 °C for 5 h. The reaction
mixture was then neutralized with 40% NaOH aq sol. Excess hydra-
zine and 1-heptanol were removed under reduced pressure, and
then the pH value was adjusted to 3.2–3.5 with 1 M HCl. The pre-
cipitated product was collected by filtration, washed by 5% ice NaCl
aq soln and recrystallized (CH2Cl2/CH3OH) to afford compound 1 as
white powder, yield 95%, mp 155–157 °C (lit.15 mp 154–155 °C).
4.1.5.5. 1H-Benzo[d][1,2,3]triazol-1-yl 4-methoxybenzoate (7).
White crystal, yield 82%, mp 158–159 °C. 1H NMR (CDCl3, d ppm):
8.12 (d, J = 8.3 Hz, 1H, Bt Ar–H), 7.96 (d, J = 8.5 Hz, 2H, Ar–H), 7.57–
7.52 (m, 1H, Bt Ar–H), 7.40–7.37 (m, 2H, Bt Ar–H), 7.16–7.12 (d,
J = 8.5 Hz, 2H, Ar–H), 4.01 (s, 3H, OCH3). ESI-MS: 270.1 [M+H]+.
Anal. Calcd for C14H11N3O3: C, 62.45; H, 4.12; N, 15.61. Found: C,
62.36; H, 4.04; N, 15.71.
4.1.3. Synthesis of 6-methoxy-1H-benzo[d][1,2,3]triazol-1-ol (2)
Compound 2 was obtained as white powder in 90% yield from
1-chloro-4-methoxy-2-nitrobenzene (938 mg, 5 mmol), 1-hepta-
nol (10 mL), and hydrazine hydrate (1.2 mL, 25 mmol) in a similar
manner as described for the preparation of compound 1, mp
169–171 °C (lit.19 mp 168–170 °C).
4.1.5.6. 1H-Benzo[d][1,2,3]triazol-1-yl 3,5-dimethoxybenzoate
(8). White crystal, yield 84%, mp 162–163 °C. 1H NMR (CDCl3, d
ppm): 8.10 (d, J = 8.2 Hz, 1H, Bt Ar–H), 7.58–7.54 (m, 1H, Bt Ar–
H), 7.45–7.40 (m, 2H, Bt Ar–H), 7.36 (d, J = 2.2 Hz, 2H, Ar–H), 6.86
(d, J = 2.2 Hz, 1H, Ar–H), 3.98 (s, 6H, OCH3). ESI-MS: 300.1
[M+H]+. Anal. Calcd for C15H13N3O4: C, 60.20; H, 4.38; N, 14.04.
Found: C, 60.26; H, 4.16; N, 14.28.
4.1.4. Synthesis of 1H-benzo[d][1,2,3]triazole (17)
To a solution of benzene-1,2-diamine (541 mg, 5 mmol) in
AcOH (10 mL), NaNO2 aq soln (25 mL, 1 M) was added and the
solution was stirred at 70–80 °C for 1 h. And then the pH value
was adjusted to 4.4–4.6 by 40% NaOH aq soln and 1 M HCl. The pre-
cipitated product was collected by filtration, washed by 5% ice NaCl
aq soln and recrystallized (CH2Cl2/CH3OH) to afford compound 17
as white powder, yield 90%, mp 98–100 °C (lit.20 mp 99–101 °C).
4.1.5.7. 1H-Benzo[d][1,2,3]triazol-1-yl 3,4,5-trimethoxybenzo-
ate (9). White crystal, yield 85%, mp 175–176 °C. 1H NMR (CDCl3,
d ppm): 8.12 (d, J = 8.4 Hz, 1H, Bt Ar–H), 7.60–7.54 (m, 1H, Bt Ar–
H), 7.52 (s, 2H, Ar–H), 7.50–7.43 (m, 2H, Bt Ar–H), 4.00 (s, 3H,
OCH3), 3.97 (s, 6H, OCH3). 13C NMR (CDCl3, d ppm): 162.4, 153.4
(2C), 144.2, 143.6, 128.9, 128.7, 124.8, 120.6, 119.1, 108.4, 108.1
(2C), 61.1, 56.5 (2C). EI-MS m/z (%): 212 (100), 197 (56), 195 (27),
119 (12), 91 (9). ESI-MS: 330.1 [M+H]+. Anal. Calcd for
4.1.5. General synthesis method of benzotriazoles 3–16 and
18–24
C16H15N3O5: C, 58.36; H, 4.59; N, 12.76. Found: C, 58.65; H, 4.62;
N, 12.64.
To a solution of triazole (1, 2, or 17, 2.5 mmol) and substituted
benzoic acid (hydroxyl or methoxyl, 2.5 mmol) in CH2Cl2 (30 mL),
EDCÁHCl (575 mg, 3 mmol) was added at rt. After being stirred
for 24 h, the mixture was evaporated under reduced pressure to
give a residue. The residue was purified by silica gel chromatogra-
phy (PE/EtOAc = 1:1) and recrystallized from PE/EtOAc to afford
benzotriazole (3–16 or 18–24).
4.1.5.8. 6-Methoxy-1H-benzo[d][1,2,3]triazol-1-yl benzoate
(10). White crystal, yield 81%, mp 96–97 °C. 1H NMR (CDCl3, d
ppm): 8.26–8.24 (m, 2H, Ar–H), 8.02 (d, J = 8.4 Hz, 1H, Bt Ar–H),
7.78–7.74 (m, 1H, Ar–H), 7.60–7.57 (m, 2H, Ar–H), 7.46–7.42 (m,
1H, Bt Ar–H), 7.10–7.05 (m, 1H, Bt Ar–H), 3.92 (s, 3H, OCH3). ESI-
MS: 270.1 [M+H]+. Anal. Calcd for C14H11N3O3: C, 62.45; H, 4.12;
N, 15.61. Found: C, 62.35; H, 4.02; N, 15.76.
4.1.5.1. 1H-Benzo[d][1,2,3]triazol-1-yl benzoate (3). White solid,
yield 80%, mp 82–83 °C. 1H NMR (CDCl3, d ppm): 8.29–8.25 (m, 2H,
Ar–H), 8.11 (d, J = 8.3 Hz, 1H, Bt Ar–H), 7.80–7.76 (m, 1H, Ar–H),
7.61–7.58 (m, 2H, Ar–H), 7.55–7.51 (m, 1H, Bt Ar–H), 7.32–7.29
(m, 2H, Bt Ar–H). ESI-MS: 240.1 [M+H]+. Anal. Calcd for
4.1.5.9. 6-Methoxy-1H-benzo[d][1,2,3]triazol-1-yl 4-hydroxy-
benzoate (11). White crystal, yield 78%, mp 185–186 °C. 1H
NMR (CDCl3, d ppm): 8.05 (d, J = 8.2 Hz, 1H, Bt Ar–H), 7.95 (d,
J = 8.4 Hz, 2H, Ar–H), 7.49–7.44 (m, 1H, Bt Ar–H), 7.18–7.13 (m,
1H, Bt Ar–H), 7.21 (d, J = 8.4 Hz, 2H, Ar–H), 3.95 (s, 3H, Bt OCH3).
ESI-MS: 286.1 [M+H]+. Anal. Calcd for C14H11N3O4: C, 58.95; H,
3.89; N, 14.73. Found: C, 58.81; H, 3.78; N, 14.85.
C13H9N3O2: C, 65.27; H, 3.79; N, 17.56. Found: C, 65.36; H, 3.95;
N, 17.34. All spectral data agreed with previously reported data.21
4.1.5.2. 1H-Benzo[d][1,2,3]triazol-1-yl 4-hydroxybenzoate (4).
White solid, yield 78%, mp 185–186 °C. 1H NMR (CDCl3, d ppm):
8.16 (d, J = 8.3 Hz, 1H, Bt Ar–H), 8.08 (d, J = 8.5 Hz, 2H, Ar–H),
7.64–7.59 (m, 1H, Bt Ar–H), 7.50–7.45 (m, 2H, Bt Ar–H), 7.38 (d,
J = 8.5 Hz, 2H, Ar–H). ESI-MS: 256.1 [M+H]+. Anal. Calcd for
4.1.5.10. 6-Methoxy-1H-benzo[d][1,2,3]triazol-1-yl 3,5-dihydro-
xybenzoate (12). White crystal, yield 72%, mp 205–206 °C. 1H
NMR (CDCl3, d ppm): 8.01 (d, J = 8.4 Hz, 1H, Bt Ar–H), 7.45–7.41
(m, 1H, Bt Ar–H), 7.36 (d, J = 2.3 Hz, 2H, Ar–H), 7.12–7.07 (m, 1H,
Bt Ar–H), 6.85 (d, J = 2.3 Hz, 1H, Ar–H), 3.91 (s, 3H, Bt OCH3). ESI-
MS: 302.1 [M+H]+. Anal. Calcd for C14H11N3O5: C, 55.82; H, 3.68;
N, 13.95. Found: C, 56.02; H, 3.78; N, 13.78.
C13H9N3O3: C, 61.18; H, 3.55; N, 16.46. Found: C, 61.36; H, 3.68;
N, 16.40.
4.1.5.3. 1H-Benzo[d][1,2,3]triazol-1-yl 3,5-dihydroxybenzoate
(5). White solid, yield 75%, mp 193–194 °C. 1H NMR (CDCl3, d
ppm): 8.11 (d, J = 8.1 Hz, 1H, Bt Ar–H), 7.60–7.57 (m, 1H, Bt Ar–
H), 7.46–7.41 (m, 2H, Bt Ar–H), 7.46 (d, J = 2.2 Hz, 2H, Ar–H), 6.90
(d, J = 2.2 Hz, 1H, Ar–H). ESI-MS: 272.1 [M+H]+. Anal. Calcd for
4.1.5.11. 6-Methoxy-1H-benzo[d][1,2,3]triazol-1-yl 3,4,5-trihy-
droxybenzoate (13). White crystal, yield 68%, mp 208–209 °C.
1H NMR (CDCl3, d ppm): 7.99 (d, J = 8.5 Hz, 1H, Bt Ar–H), 7.58 (s,
2H, Ar–H), 7.49–7.45 (m, 1H, Bt Ar–H), 7.21–7.15 (m, 1H, Bt Ar–
H), 3.95 (s, 3H, Bt OCH3). ESI-MS: 318.1 [M+H]+. Anal. Calcd for
C13H9N3O4: C, 57.57; H, 3.34; N, 15.49. Found: C, 57.42; H, 3.61;
N, 15.32.
C14H11N3O6: C, 53.00; H, 3.49; N, 13.24. Found: C, 53.07; H, 3.62;
N, 13.05.
4.1.5.4. 1H-Benzo[d][1,2,3]triazol-1-yl 3,4,5-trihydroxybenzoate
(6). White solid, yield 70%, mp 199–200 °C. 1H NMR (CDCl3, d
ppm): 8.14 (d, J = 8.3 Hz, 1H, Bt Ar–H), 7.70–7.66 (m, 1H, Bt Ar–
H), 7.57 (s, 2H, Ar–H), 7.52–7.44 (m, 2H, Bt Ar–H). ESI-MS: 288.0
[M+H]+. Anal. Calcd for C13H9N3O5: C, 54.36; H, 3.16; N, 14.63.
Found: C, 54.56; H, 3.26; N, 14.36.
4.1.5.12. 6-Methoxy-1H-benzo[d][1,2,3]triazol-1-yl 4-methoxy-
benzoate (14). White crystal, yield 83%, mp 161–162 °C. 1H NMR
(CDCl3, d ppm): 8.03 (d, J = 8.3 Hz, 1H, Bt Ar–H), 7.92 (d, J = 8.5 Hz,
2H, Ar–H), 7.47–7.43 (m, 1H, Bt Ar–H), 7.15–7.12 (m, 1H, Bt Ar–H),
7.18 (d, J = 8.5 Hz, 2H, Ar–H), 4.02 (s, 3H, Ar OCH3), 3.93 (s, 3H, Bt