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2-(o-Nitrobenzylideneamino)benzimidazole (10)
2-(3,4,5-Trimethoxybenzylamino)benzimidazole (14)
Yield 0.56 g (18%), white solid from ethanol, m.p. 107–
111 °C. IR (KBr) m cm–1 = 3380 (sec NH), 2860, 2845
(CH), 1625 (sec NH), 1500 (C=N), 1440 (–OCH3), 1225
Yield 0.70 g (26%), yellow precipitate from ethanol, m.p.
297–299 °C. IR (KBr): m cm–1 = 3390 (sec NH), 2890
(CH), 1645 (C=N), 1560 (sec NH), 1530, 1355 (NO2), 760
(CH aromat.). 1H NMR (DMSO): d = 7.22 (m, 2H), 7.60
(m, 4H), 7.93 (m, 1H), 8.43 (m, 1H), 9.75 (s, 1H), 12.85 (s,
1H). Anal.: C14H10N4O2 (266.26). MS (70 eV) m/z
(%) = 266 (72), 265 (100), 219 (27), 193 (18), 118 (35), 91
(15) 76 (16), 65 (16), 39 (12).
1
(C–O–C), 810, 760 (CH aromat.). H NMR (DMSO):
d = 3.72 (s, 3H), 3.85 (s, 6H), 4.42 (d, J = 4.60 Hz, 2H),
6.83 (m, 4H), 6.88 (t, 1H), 6.97 (s, 1H), 7.15 (m, 1H),
10.83 (br, 1H). Anal.: C17H19N3O3 (313.36). MS (70 eV)
m/z (%) = 315 (12), 313 (100), 298 (5), 282 (25), 267 (8),
212 (8), 142 (18), 118 (20), 91 (25), 65 (10), 39 (8).
2-(p-Trifluoromethylbenzylideneamino)benzimidazole
(11)
2-(o-Bromobenzylamino)benzimidazole (15)
Yield: 2.15 g (70%), white solid crystals from ethanol,
m.p. 213–215 °C. IR (KBr): m cm–1 = 3400 (sec NH), 3040
(CH), 2920 (–CH2–), 1650 (C=N), 1600 (sec NH), 1530
(C=N), 1480, 1450 (CH2), 1280 (NH), 960, 760 (aromat.).
1H NMR (DMSO): d = 4.55 (d, J = 4.52 Hz, 2H), 6.87 (s,
2H), 7.16 (m, 4H), 7.36 (m, 2H), 7.63 (d, J = 7.80 Hz, 1H),
10.91 (s, 1H). Anal.: C14H12N3Br (302.17). MS (70 eV):
m/z (%) = 304 (3), 303 (17), 302 (5), 301 (18), 223 (13),
222 (100), 220 (11), 171 (11), 105 (9), 91 (8), 90 (15).
Yield 1.95 g (67%) yellow precipitate crystallised from
ethanol, m.p. 238–240 °C. IR (KBr): m cm–1 = 3400 (sec
NH), 3000 (CH aromat.), 2840 (CH), 1635 (C=N), 1580
(C=N ring), 870 (CH aromat. 1,4-disubstituted), 750 (CH
1
aromat. 1,2-disubstituted). H NMR (DMSO): d = 7.21
(m, 2H), 7.54 (m, 2H), 7.93 (d, J = 8.04 Hz, 2H), 8.27 (d,
J = 7.99 Hz, 2H), 9.56 (s, 1H), 12.83 (br, 1H). Anal.:
C15H10N3F3 (289.26). MS (70 eV): m/z (%) = 289.1
(47.36), 288.1 (100.00), 262.1 (6.52), 261.1 (4.84), 220.1
(2.36), 118.1 (6.83), 91.1 (3.18), 90.1 (3.39), 65.1 (0.98),
64.1 (1.21), 39.1 (0.44).
2-(p-Bromobenzylamino)benzimidazole (16)
Yield 1.83 g (61%), white crystal from ethanol, m.p.
195–197 °C. IR (KBr): m cm–1 = 3330 (NH), 3030
(–CH–), 2920 (–CH2–), 1650 (C=N), 1620, 1330 (NH),
3.1.2. Reduction of Schiff bases 1–11 with NaBH4, 12–21
1
860, 760 (CH aromat.). H NMR (DMSO): d = 4.45 (d,
One portion of NaBH4 (0.01 mol) was added to boiling
mixture of 0.01 mol of appropriate compound in 250 ml of
isopropanol during heating for 3–4 h (TLC). Then the alco-
hol was refluxed under reduced pressure and 200 ml of water
was added to cold and dry residue. Undissolved residue was
filtered, washed with water (ca. 1500 ml) to neutral reaction.
After drying precipitates were crystallised.
J = 4.31 Hz, 2H), 7.00 (br, 1H), 7.12 (m, 2H), 7.35 (d,
J = 8.60 Hz, 2H), 7.60 (m, 2H), 8.03 (d, J = 8.60 Hz, 2H),
11.0 (s, 1H). Anal.: C14H12N3Br (302.17). MS (70 eV):
m/z (%) = 304 (12), 303 (74), 302 (38), 301 (100), 223 (5),
222 (8), 221 (6), 220 (9), 146 (13), 132 (26), 105 (19), 91
(13), 90 (47), 89 (18), 63 (11), 39 (12).
2-(o-Chlorobenzylamino)benzimidazole (17)
2-(p-Methoxybenzylamino)benzimidazole (12)
Yield 2.01 g (78%), white crystals from ethanol, m.p.
212–214 °C. IR (KBr): m cm–1 = 3320 (sec NH), 1620
(C=N), 1600, 1580 (sec NH), 1450 (CH2), 1350, 1260
(NH), 830, 730 (CH aromat.), 1H NMR (DMSO): d = 4.55
(d, J = 4.52 Hz, 2H), 6.95 (m, 2H), 7.12 (m, 3H), 7.19 (td,
1H), 7.32 (td, 1H), 7.40 (m, 1H), 7.61 (dd, 1H), 10.88 (s,
br, 1H). Anal.: C14H12N3Cl (257.72). MS (70 eV): m/z
(%) = 258 (6), 257 (43), 223 (30), 222 (100), 220 (25), 171
(36), 132 (32), 91 (21), 90 (79), 89 (32), 78 (13), 77 (13),
76 (6), (10), 64 (12), 63 (23), 39 (15).
Yield 1.27 g (50%), white precipitate crystallised from
acetonitrile, m.p. 207–208 °C. IR (KBr): m cm–1 = 3300
(sec NH), (CH), 2820 (–OCH3), 1625 (NH, C=N), 1500
(C=N), 1335 (sec NH, CH), 1050 (NH), 810, 730 (CH
1
aromat.). H NMR (DMSO): d = 3.70 (s, 3H), 4.42 (d,
J = 4.42 Hz, 2H), 6.85 (m, 4H), 7.05 (t, 1H), 7.17 (m, 2H),
7.29 (d, J = 8.58 Hz, 2H), 10.87 (br, 1H). Anal.:
C15H15N3O (253.29). MS (70 eV): m/z (%) = 254 (6), 253
(40), 122 (10), 121 (100), 119 (3), 105 (3), 91 (7), 90 (3),
78 (9), 77 (9), 65 (3), 51 (3), 41 (4), 39 (3).
2-(m-Chlorobenzylamino)benzimidazole (18)
2-(3,4-Dimethoxybenzylamino)benzimidazole (13)
Yield 0.98 g (38%), white solid from ethanol, m.p. 170–
172 °C. IR (KBr): m cm–1 = 3400 (sec NH), 3040 (CH),
2920 (–CH2–), 1650 (C=N), 1600 (sec NH), 1530 (C=N),
1480, 1450 (CH2), 1280 (NH), 900, 760 (CH aromat), 1H
NMR (DMSO): d = 4.40 (d, J = 4.49 Hz, 2H), 6.74 (s, 1H),
6.89 (s, 1H), 7.18 (m, 4H), 7.48 (m, 3H), 10.87 (s, br, 1H).
Anal.: C14H12N3Cl (257,12). MS (70 eV): m/z (%) = 259
(14), 258 (7), 257 (45), 223 (28), 222 (100), 171 (35), 132
(30), 90 (80), 77 (18), 65 (8), 63 (21), 39 (12).
Yield 0.75 g (27%), white precipitate crystallised from
acetonitrile, m.p. 234.5–236 °C. IR (KBr): m cm–1 = 3280
(NH), 3020 (CH), 2810 (–OCH3), 1625 (sec NH), 1500
(C=N), 1400 (–OCH3), 1255 (C–O–C), 1220, 880, 730
(CH). 1H NMR (DMSO): d = 3.72(s, 6H), 4.41(d,
J = 4.48 Hz, 2H), 6.84(m, 4H), 6.98(t, 1H), 7.01(s, 1H),
7.11(t, 2H), 10.79 (br, 1H). Anal.: C16H17N3O2 (283.33).
MS (70 eV): m/z (%) = 284 (4), 283 (24), 152 (8), 151
(100), 133 (4), 121 (5), 107 (5), 106 (5), 105 (5), 91 (4), 90
(4), 78 (4), 77 (3), 51 (31), 39 (3).
2-(p-Chlorobenzyloamino)benzimidazol (19)