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LI ET AL.
(m, 7H), 2.20 (d, J = 12.2 Hz, 1H), 2.29 (d, J = 12.7 Hz,
1H), 2.77 (brs, 1H), 2.91 (dd, J = 16.6, 6.1 Hz, 1H), 3.69
(s, 3H), 7.27 (s, 1H), 8.03 (d, J = 8.7 Hz, 2H), 8.09 (d,
J = 8.7 Hz, 2H), 10.15 (brs, 2H); 13C NMR (150 MHz,
CDCl3): δ16.6, 18.6, 20.8, 25.1, 25.4, 36.7, 37.6, 38.3, 44.9,
47.6, 52.2, 100.7, 122.9, 123.8, 125.3, 128.5, 129.3, 129.5,
139.5, 146.7, 149.5, 150.1, 168.6, 178.9; ESI-MS: m/z [M
+ H]+ calcd for C26H28BrN4O5: 555.1236; found:
555.1248.
2H), 7.20 (s, 1H), 7.77 (d, J = 8.2 Hz, 2H), 9.80 (brs, 1H),
10.44 (brs, 1H); 13C NMR (150 MHz, CDCl3): δ 16.6, 18.5,
20.6, 21.6, 24.5, 25.4, 36.7, 37.6, 38.4, 44.7, 47.6, 52.3,
100.5, 118.5, 122.3, 125.5, 126.1, 127.9, 129.5, 140.3, 142.6,
147.2, 150.6, 178.9; ESI-MS: m/z [M + H]+ calcd for
C26H31BrN3O4S: 560.1212; found: 560.1223.
3.3.3 | Compound 8c
1
Light yellow solid, yield 70%, m.p. 242–244ꢀC; H NMR
3.3 | General procedure for the synthesis
of N-(1H-benzo[d]imidazol-2-yl)-
benzenesulfonamide derivatives (8a–h)
(600 MHz, CDCl3): δ 1.19 (s, 3H), 1.26 (s, 3H), 1.46 (t,
J = 11.8 Hz, 1H), 1.53 (dd, J = 12.5, 7.6 Hz, 1H), 1.65–
1.85 (m, 5H), 2.18 (d, J = 12.5 Hz, 1H), 2.25 (d,
J = 12.4 Hz, 1H), 2.81 (m, 1H), 2.97 (dd, J = 17.2, 6.3 Hz,
1H), 3.67 (s, 3H), 3.81 (s, 3H), 6.83 (d, J = 8.2 Hz, 2H),
7.19 (s, 1H), 7.80 (d, J = 8.3 Hz, 2H), 9.90 (brs, 1H), 10.51
(brs, 1H); 13C NMR (150 MHz, CDCl3): δ 16.6, 18.6, 20.6,
24.5, 25.4, 36.7, 37.6, 38.4, 44.7, 47.6, 52.3, 55.6, 100.4,
114.0, 118.6, 122.2, 125.5, 127.9, 128.0, 135.3, 147.2, 150.7,
162.4, 178.9; ESI-MS: m/z [M + H]+ calcd for
C26H31BrN3O5S: 576.1161; found: 576.1163.
To a solution of compound 6 (81 mg, 0.2 mmol) in 2 ml
of pyridine was added 0.6 mmol of corresponding
substituted benzenesulfonyl chloride. The mixture was
stirred at 100ꢀC for 6 hr, and the reaction was monitored
by TLC. At the end of reaction, the mixture was poured
into water (50 ml) and extracted with EtOAc (3 × 50 ml).
The organic phase was combined, washed with water,
saturated NaHCO3 solution, and brine, dried over anhy-
drous Na2SO4 and concentrated in vacuo. The residue
was purified by column chromatography on silica gel and
eluted with petroleum ether-acetone (100:1–10:1, vol/vol)
to afford compounds 8a–h.
3.3.4 | Compound 8d
1
Light yellow solid, yield 62%, m.p. 128–130ꢀC; H NMR
(600 MHz, CDCl3): δ 1.20 (s, 3H), 1.27 (s, 3H), 1.46 (t,
J = 12.4 Hz, 1H), 1.55 (dd, J = 13.1, 7.6 Hz, 1H), 1.65–
1.85 (m, 5H), 2.19 (d, J = 11.3 Hz, 1H), 2.26 (d,
J = 13.4 Hz, 1H), 2.80 (m, 1H), 2.92 (dd, J = 17.2, 6.6 Hz,
1H), 3.68 (s, 3H), 7.07 (t, J = 8.5 Hz, 2H), 7.22 (s, 1H),
7.91 (dd, J = 8.6, 5.2 Hz, 2H), 9.66 (brs, 1H), 10.24 (brs,
1H); 13C NMR (150 MHz, CDCl3): δ 16.6, 18.5, 20.6, 24.5,
25.4, 36.7, 37.6, 38.4, 44.7, 47.6, 52.3, 100.6, 116.0 (d,
J = 22.4 Hz), 118.5, 122.5, 125.4, 127.7, 128.7 (d,
J = 9.2 Hz), 139.4 (d, J = 3.1 Hz), 147.4, 150.4, 164.7 (d,
J = 251.7 Hz), 178.9; ESI-MS: m/z [M + H]+ calcd for
C25H28BrFN3O4S: 564.0961; found: 564.0972.
3.3.1 | Compound 8a
Yellow solid, yield 75%, m.p. 136–138ꢀC; 1H NMR
(600 MHz, CDCl3): δ 1.18 (s, 3H), 1.25 (s, 3H), 1.45 (td,
J = 12.7, 3.2 Hz, 1H), 1.52 (dd, J = 13.1, 8.0 Hz, 1H),
1.60–1.85 (m, 5H), 2.18 (dd, J = 12.5, 1.8 Hz, 1H), 2.25 (d,
J = 12.9 Hz, 1H), 2.80 (m, 1H), 2.97 (dd, J = 17.5, 6.7 Hz,
1H), 3.66 (s, 3H), 7.20 (s, 1H), 7.36 (t, J = 7.9 Hz, 2H),
7.46 (t, J = 7.4 Hz, 1H), 7.88 (d, J = 7.4 Hz, 2H); 13C
NMR (150 MHz, CDCl3): δ16.5, 18.5, 20.5, 24.5, 25.4,
36.7, 37.6, 38.3, 44.6, 47.6, 52.3, 100.5, 118.7, 122.3, 125.5,
126.0, 127.9, 128.9, 131.9, 143.2, 147.2, 150.7, 178.9; ESI-
MS: m/z [M + H]+ calcd for C25H29BrN3O4S: 546.1055;
found: 546.1069.
3.3.5 | Compound 8e
1
Light yellow solid, yield 76%, m.p. 229–230ꢀC; H NMR
(600 MHz, CDCl3): δ 1.19 (s, 3H), 1.26 (s, 3H), 1.44 (td,
J = 12.3, 3.9 Hz, 1H), 1.52 (dd, J = 12.8, 7.9 Hz, 1H),
1.60–1.85 (m, 5H), 2.17 (dd, J = 12.1, 1.7 Hz, 1H), 2.25 (d,
J = 13.1 Hz, 1H), 2.80 (m, 1H), 2.94 (dd, J = 17.4, 6.7 Hz,
1H), 3.67 (s, 3H), 7.21 (s, 1H), 7.31 (d, J = 8.6 Hz, 2H),
7.80 (d, J = 8.6 Hz, 2H), 10.01 (brs, 1H), 10.52 (brs, 1H);
13C NMR (150 MHz, CDCl3): δ 16.5, 18.5, 20.5, 24.5, 25.4,
36.7, 37.6, 38.3, 44.6, 47.6, 52.3, 100.6, 118.6, 122.5, 125.5,
127.5, 127.8, 129.1, 138.2, 141.8, 147.3, 150.5, 178.9; ESI-
3.3.2 | Compound 8b
1
Light yellow solid, yield 64%, m.p. 217–219ꢀC; H NMR
(600 MHz, CDCl3): δ 1.19 (s, 3H), 1.26 (s, 3H), 1.46 (t,
J = 12.3 Hz, 1H), 1.53 (dd, J = 12.8, 7.8 Hz, 1H), 1.65–
1.85 (m, 5H), 2.19 (dd, J = 12.9, 1.7 Hz, 1H), 2.25 (d,
J = 11.9 Hz, 1H), 2.37 (s, 3H), 2.79 (m, 1H), 2.94 (dd,
J = 17.3, 6.6 Hz, 1H), 3.67 (s, 3H), 7.17 (d, J = 8.1 Hz,