Chemistry of Heterocyclic Compounds 2021, 57(5), 581–587
H Ar); 7.30–7.29 (2H, m, H Ar); 6.90 (1H, s, H Ar); 6.87
2-(5,6-Dimethyl-1H-benzimidazol-2-yl)phenol (3i). Yield
(1H, d, J = 8.0, H Ar); 2.35 (3H, s, CH3). 13C NMR
spectrum (DMSO-d6), δ, ppm: 158.0 (C–OH); 151.9
(C=N); 142.0; 126.0 (2C); 122.5; 120.1 (2C); 117.8; 117.4
(2C); 111.4; 110.0; 21.1 (CH3). Found, m/z: 224.0944
[M+H]+. C14H12N2O. Calculated, m/z: 224.0950.
1.763 g (74%), white solid, mp 238–239°C. IR spectrum,
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ν, cm–1: 3256 (NH), 1636 (C=N), 1590 (C=C). H NMR
spectrum (DMSO-d6), δ, ppm (J, Hz): 13.24 (1H, s, NH);
12.94 (1H, s, OH); 8.00 (1H, d, J = 7.6, H Ar); 7.46 (1H, s,
H Ar); 7.34 (2H, t, J = 7.7, H Ar); 6.99 (2H, m, H Ar); 2.33
(6H, s, 2CH3). 13C NMR spectrum (DMSO-d6), δ, ppm:
157.9 (C–OH); 150.8 (C=N); 131.3 (2C); 125.9 (2C); 119.0
(2C); 117.9; 117.1 (2C); 112.8; 111.5; 20.0 (2CH3). Found,
m/z: 238.1101 [M+H]+. C15H14N2O. Calculated, m/z: 238.1106.
2-(5,6-Dimethyl-1H-benzimidazol-2-yl)-6-methylphenol
(3j). Yield 1.539 g (61%), yellow solid, mp 297–298°C.
IR spectrum, ν, cm–1: 3342 (NH), 1632 (C=N), 1601
2-(1H-Benzimidazol-2-yl)-4-methylphenol (3d). Yield
1.637 g (73%), yellow solid, mp 247–248°C. IR spectrum,
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ν, cm–1: 3289 (NH), 1637 (C=N), 1586 (C=C). H NMR
spectrum (DMSO-d6), δ, ppm (J, Hz): 13.16 (1H, s, NH);
12.94 (1H, s, OH); 7.91 (1H, s, H Ar); 7.72 (1H, s, H Ar);
7.64 (1H, s, H Ar); 7.29 (2H, s, H Ar); 7.20 (1H, d, J = 8.3,
H Ar); 6.97 (1H, d, J = 8.3, H Ar); 2.35 (3H, s, CH3).
13C NMR spectrum (DMSO-d6), δ, ppm: 155.9 (C–OH);
151.8 (C=N); 141.0; 133.2; 132.4; 127.6; 126.2; 123.1;
122.3; 117.9; 117.0; 112.2; 111.5; 20.2 (CH3). Found, m/z:
224.0942 [M+H]+. C14H12N2O. Calculated, m/z: 224.0950.
2-(1H-Benzimidazol-2-yl)-6-methoxyphenol (3e). Yield
1.754 g (73%), white solid, mp 217–218°C. IR spectrum,
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(C=C). H NMR spectrum (DMSO-d6), δ, ppm (J, Hz):
13.64 (1H, s, NH); 13.00 (1H, s, OH); 7.91 (1H, d, J = 7.6,
H Ar); 7.55 (1H, s, H Ar); 7.42 (1H, s, H Ar); 7.30 (1H, d,
J = 7.2, H Ar); 6.96 (1H, t, J = 7.6, H Ar); 2.42 (3H, s,
CH3); 2.40 (3H, s, CH3); 2.32 (3H, s, CH3). 13C NMR
spectrum (DMSO-d6), δ, ppm: 156.2 (C–OH); 151.2
(C=N); 139.3; 132.1; 132.0; 131.6; 130.8; 125.5; 123.3;
118.4; 117.9; 111.8; 111.4; 20.0 (CH3); 19.9 (CH3); 15.8
(CH3). Found, m/z: 252.1257 [M+H]+. C16H16N2O.
Calculated, m/z: 252.1263.
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ν, cm–1: 3335 (NH), 1626 (C=N), 1593 (C=C). H NMR
spectrum (DMSO-d6), δ, ppm (J, Hz): 13.28 (2H, s, OH,
NH); 7.76–7.69 (3H, m, H Ar); 7.32 (2H, s, H Ar); 7.09
(1H, d, J = 7.9, H Ar); 6.98 (1H, t, J = 8.0, H Ar); 3.87
(3H, s, OCH3). 13C NMR spectrum (DMSO-d6), δ, ppm:
152.0 (C–OH); 148.6 (C=N); 148.4; 140.8; 133.1; 123.3;
122.5; 118.7; 118.0; 117.6; 113.9; 112.6; 111.6; 55.7
(OCH3). Found, m/z: 240.0895 [M+H]+. C14H12N2O2.
Calculated, m/z: 240.0899.
2-(5,6-Dimethyl-1H-benzimidazol-2-yl)-5-methylphenol
(3k). Yield 1.716 g (68%), yellow solid, mp 238–239°C.
IR spectrum, ν, cm–1: 3235 (NH), 1648 (C=N), 1585
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(C=C). H NMR spectrum (DMSO-d6), δ, ppm (J, Hz):
13.24 (1H, s, NH); 12.91 (1H, s, OH); 7.95 (1H, d, J = 7.0,
H Ar); 7.56–7.42 (2H, m, H Ar); 6.97–6.81 (2H, m, H Ar);
2.39 (6H, s, 2CH3); 2.38 (3H, s, CH3). 13C NMR spectrum
(DMSO-d6), δ, ppm: 157.8 (C–OH); 151.1 (C=N); 141.5;
139.4; 131.8; 131.5; 130.7; 125.7; 120.0; 117.8; 117.3;
111.3; 110.2; 21.1 (CH3); 20.0 (CH3); 19.9 (CH3). Found, m/z:
252.1256 [M+H]+. C16H16N2O. Calculated, m/z: 252.1263.
2-(5,6-Dimethyl-1H-benzimidazol-2-yl)-4-methylphenol
(3l). Yield 1.791 g (71%), yellow solid, mp 244–246°C.
IR spectrum, ν, cm–1: 3278 (NH), 1637 (C=N), 1581
2-(1H-Benzimidazol-2-yl)-5-methoxyphenol (3f). Yield
1.850 g (77%), white solid, mp 238–239°C. IR spectrum,
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ν, cm–1: 3347 (NH), 1619 (C=N), 1590 (C=C). H NMR
spectrum (DMSO-d6), δ, ppm (J, Hz): 13.46 (1H, s, NH);
13.08 (1H, s, OH); 8.02 (1H, d, J = 8.6, H Ar); 7.70 (1H, s,
H Ar); 7.62 (1H, s, H Ar); 7.28 (2H, d, J = 4.3, H Ar); 6.67
(2H, dt, J = 6.3, J = 2.4, H Ar); 3.84 (3H, s, OCH3).
13C NMR spectrum (DMSO-d6), δ, ppm: 162.2 (C–OH);
160.0 (C=N); 152.1; 140.8; 127.3; 122.8; 122.2; 117.5 (2C);
111.2; 106.5; 105.7; 101.5; 55.3 (OCH3). Found, m/z:
240.0899 [M+H]+. C14H12N2O2. Calculated, m/z: 240.2573.
2-(1H-Benzimidazol-2-yl)-4-methoxyphenol (3g). Yield
1.874 g (78%), white solid, mp 283–284°C. IR spectrum,
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(C=C). H NMR spectrum (DMSO-d6), δ, ppm (J, Hz):
13.03 (1H, s, NH); 12.91 (1H, s, OH); 7.86 (1H, s, H Ar);
7.48 (1H, s, H Ar); 7.38 (1H, s, H Ar); 7.17 (1H, d, J = 7.6,
H Ar); 6.94 (1H, d, J = 8.0, H Ar); 2.34 (9H, s, 3CH3).
13C NMR spectrum (DMSO-d6), δ, ppm: 155.8 (C–OH);
150.9 (C=N); 132.0 (2C); 127.5 (2C); 125.8 (2C); 117.9; 116.8
(2C); 112.4; 111.4; 20.2 (CH3); 19.9 (2CH3). Found, m/z:
252.1268 [M+H]+. C16H16N2O. Calculated, m/z: 252.1263.
2-(5,6-Dimethyl-1H-benzimidazol-2-yl)-6-methoxyphenol
(3m). Yield 1.851 g (69%), yellow solid, mp 239–241°C.
IR spectrum, ν, cm–1: 3318 (NH), 1637 (C=N), 1592
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ν, cm–1: 3314 (NH), 1612 (C=N), 1590 (C=C). H NMR
spectrum (DMSO-d6), δ, ppm (J, Hz): 13.14 (1H, s, NH);
12.77 (1H, s, OH); 7.71 (3H, d, J = 1.7, H Ar); 7.32–7.30
(2H, m, H Ar); 7.04–7.00 (2H, m, H Ar); 3.84 (3H, s, OCH3).
13C NMR spectrum (DMSO-d6), δ, ppm: 152.0 |(C–OH);
151.9 (C=N); 150.8; 139.6; 132.1; 131.6; 130.9; 118.3; 118.0;
117.8; 112.5; 111.4; 109.7; 55.7 (OCH3). Found, m/z:
240.0899 [M+H]+. C14H12N2O2. Calculated, m/z: 240.2573.
2-(1H-Benzimidazol-2-yl)-4-bromophenol (3h). Yield
1.157 g (40%), white solid, mp 220–221°C. IR spectrum,
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(C=C). H NMR spectrum (DMSO-d6), δ, ppm (J, Hz):
13.47 (1H, s, NH); 13.00 (1H, s, OH); 7.67 (1H, d, J = 7.9,
H Ar); 7.56 (1H, s, H Ar); 7.42 (1H, s, H Ar); 7.11 (1H, d,
J = 7.8, H Ar); 6.99 (1H, t, J = 8.0, H Ar); 3.90 (3H, s,
OCH3); 2.40 (6H, s, 2CH3). 13C NMR spectrum (DMSO-d6),
δ, ppm: 151.1 (C–OH); 148.6 (C=N); 148.2; 139.3; 132.1;
131.5; 130.9; 118.5; 117.9; 117.4; 113.6; 112.7; 111.4;
55.7 (OCH3); 19.9 (2CH3). Found, m/z: 268.1207 [M+H]+.
C16H16N2O2. Calculated, m/z: 268.1212.
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ν, cm–1: 3346 (NH), 1636 (C=N), 1582 (C=C). H NMR
spectrum (DMSO-d6), δ, ppm (J, Hz): 13.29 (2H, s, OH,
NH); 8.29 (1H, s, H Ar); 7.70 (1H, s, H Ar); 7.64 (1H, s,
H Ar); 7.51 (1H, d, J = 8.4, H Ar); 7.29 (2H, s, H Ar); 7.01
(1H, d, J = 8.7, H Ar). 13C NMR spectrum (DMSO-d6),
δ, ppm: 157.2 (C–OH, C=N); 150.3 (2C); 133.9 (2C);
128.4 (2C); 123.1; 119.4 (2C); 114.6; 110.1. Found, m/z:
287.9891 [M+H]+. C13H9BrN2O. Calculated, m/z: 287.9898.
2-(5,6-Dimethyl-1H-benzimidazol-2-yl)-5-methoxyphenol
(3n). Yield 1.958 g (73%), yellow solid, mp 294–295°C.
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