602
B. Behramand et al. / Dyes and Pigments 95 (2012) 600e605
1247. CI-MS [M þ H]þ calculated for C70H108N2O4S m/z: 1072.8;
Found: 1073.9. CHN: Expected: C 78.31, H 10.14, N 2.61. Found: C
78.26, H 10.14, N 2.57.
alkylated product 13a as needle-like white crystals. Yield: 86%,
m.p. ¼ 45.2e46.3 ꢀC (lit. 45.0e48.0 ꢀC). 1H NMR (CDCl3, 400 MHz):
d
¼ 6.9 (s, 4H), 4.0 (t, 4H, J ¼ 6.6 Hz), 1.8 (m, 4H), 1.3 (br), 0.9 (t, 6H,
J ¼ 7.0 Hz). 13C NMR (CDCl3, 100.6 MHz)
d: 149.4, 121.2, 114.3, 69.5,
2.2.6. 4,7-Bis((3,4-bis(dodecyloxy)phenyl)ethynyl)-5,6-
bis(dodecyloxy)-2,1,3-benzothiadiazole (6)
32.2, 29.9, 29.6, 26.3, 22.9, 14.4. FT-IR (KBr, cmꢁ1): 2925, 2853, 1594,
1510, 1465, 1258, 1217, 1128, 747, 723.
Lime colored solid; yield: 51%, m.p. ¼ 80.0e81.7 ꢀC.1H NMR
(CDCl3, 400 MHz):
d
¼ 7.2 (dd, 2H, J ¼ 8.2 Hz, J4 ¼ 2.0 Hz), 7.2 (d, 2H,
2.2.13. 1,2-Dimethoxybenzene/Veratrol (13b)
J4 ¼ 2.0 Hz), 6.9 (d, 2H, J ¼ 8.4 Hz), 4.4 (t, 4H, J ¼ 6.6 Hz), 4.0 (ot, 8H),
A mixture of catechol (11.95 g, 108.57 mmol) and K2CO3 (37.45 g,
271.4 mmol) in acetone was stirred under argon for 10 min at room
temperature. Iodomethane (14.2 mL, 228 mmol) was added, stirred
for 1.5 h at room temperature and then heated under refluxovernight
at 60 ꢀC. The reaction mixture was cooled to room temperature,
vacuum filtered to remove K2CO3 and the filtrate concentrated under
reduced pressure to furnish the oily product (14.6 g, 98%). 1H NMR
1.9 (qui), 1.8 (qui), 1.3 (br), 0.9 (t). 13C NMR (CDCl3, 100.6 MHz)
d:
157.7, 152.1, 150.5, 149.0, 125.6, 116.8, 115.1, 113.2, 108.5, 101.6, 80.8,
75.3, 69.5, 69.3, 32.2, 30.0, 29.9, 29.6, 29.4, 26.3, 23.0, 14.1. FT-IR
(KBr, cmꢁ1): 2922, 2852, 2205, 1605, 1505, 1468, 1290, 1246. CHN:
Expected: C 78.28, H 10.90, N 1.94. Found: C 78.29, H 10.80, N 1.90.
2.2.7. 4,7-Dibromo-5,6-bis(dodecyloxy)-2,1,3-benzoxadiazole (7)
Off-white solid; yield: 90%, m.p. ¼ 55.0e56.1 ꢀC. 1H NMR (CDCl3,
(CDCl3, 400 MHz):
3055, 3000, 2853, 1610, 1494, 1476, 1322, 1253, 1152, 1120, 1004, 753.
d
¼ 6.8 (m, 4H), 3.7 (s, 6H). FT-IR (KBr, cmꢁ1): 3103,
400 MHz):
d
¼ 4.2 (t, 4H, J ¼ 6.6 Hz), 1.9 (m, 4H), 1.5 (m, 4H), 1.3 (br),
0.9 (t, 6H, J ¼ 0.7 Hz). FT-IR (KBr, cmꢁ1): 2954, 2919, 2851, 2331,
1734, 1612, 1473, 1380, 1296, 1187, 1072, 1014, 996, 948, 883, 723.
CHN: Expected C30H50Br2N2O3: C 55.73, H 7.79, N 4.33. Found: C
55.72, H 7.80, N 4.30.
2.2.14. 1,2-Bis(dodecyloxy)-4,5-dinitrobenzene (14a) [23]
Prepared as reported for an analogous conversion. Bright yellow
solid; yield: 88%, m.p. ¼ 79.0e80.0 ꢀC (lit. 81.0e82.0 ꢀC). 1H NMR
(CDCl3, 400 MHz):
d
¼ 7.3 (s, 2H), 4.1 (t, 4H, J ¼ 6.4 Hz), 1.9 (m, 4H),
1.5 (m), 1.3 (br), 0.9 (t, 6H, J ¼ 7.0 Hz). 13C NMR (CDCl3, 100.6 MHz)
d:
2.2.8. 4,7-Dibromo-5,6-dimethoxy-2,1,3-benzoxadiazole (8)
152, 136.7, 108, 70.4, 32.16, 29.9, 29.5, 28.9, 22.9, 14.4. FT-IR (KBr,
cmꢁ1): 2123, 3070, 2917, 2850, 1727, 1586, 1529, 1465, 1372, 1334,
1289, 1225, 1070, 1041, 987, 949, 909, 872, 823.
Recrystallized from methanol. Off-white crystalline solid; yield:
49%, m.p. ¼ 128.5e131.0 ꢀC.1H NMR (CDCl3, 400 MHz):
d
¼ 4.0 (s).
FT-IR (KBr, cmꢁ1): 3010, 2952, 2847, 2363, 2136, 1608, 1530, 1477,
1382, 1310, 1075, 1010, 973, 879, 844, 732. CHN: Expected
C8H6Br2N2O3: C 28.43, H 1.79, N 8.29. Found: C 28.41, H 1.80, N 8.29.
2.2.15. 1,2-Dimethoxy-4,5-dinitrobenzene (14b) [24]
Prepared according to previously reported procedure. Bright
yellow colored fine crystals; yield: 72%, m.p. ¼ 128.2e129.5 ꢀC (lit.
2.2.9. 4,7-Dibromo-5,6-bis(dodecyloxy)-2,1,3-benzothiadiazole (9)
[19]
129.0e131.0 ꢀC). 1H NMR (CDCl3, 400 MHz):
d
¼ 7.3 (s, 2H), 4.0 (s,
6H). FT-IR (KBr, cmꢁ1): 3067, 2986, 1585, 1522, 1370, 1325, 1287,
1234, 1045, 875, 789.
Off-white fluffy crystalline solid; yield: 73%, m.p. ¼ 60.4e61.0 ꢀC
(lit. 64e65 ꢀC). 1H NMR (CDCl3, 400 MHz):
d
¼ 4.2 (t, 4H, J ¼ 6.6 Hz),
1.9 (m, 4H), 1.3 (br), 0.9 (t, 6H, J ¼ 7.0 Hz). 13C NMR (CDCl3, 125 MHz)
2.2.16. 5,6-Bis(dodecyloxy)-2,1,3-benzothiadiazole (16) [19]
d
: 154.5, 150.3, 106.2, 75.1, 31.9, 29.68, 29.65, 29.62, 29.60, 29.4, 29.3
Recrystallized from ethanol. Off-white crystalline solid; yield:
25.9, 22.6, 14.1. FT-IR (KBr, cmꢁ1): 2958, 2903, 2845, 1471, 1384,
1292, 985, 946.
73%, m.p. ¼ 95.0e96.7 ꢀC. 1H NMR (CDCl3, 400 MHz):
¼ 7.1 (s, 2H),
d
4.1 (t, 4H, J ¼ 6.6 Hz), 1.9 (m, 4H), 1.5 (m, 4H), 1.3 (br), 0.9 (t, 6H,
J ¼ 7.0). 13C NMR (CDCl3, 100 MHz)
d: 154.0, 151.3, 98.3, 69.1, 31.9,
2.2.10. 1-Dodecyloxy-4-ethynylbenzene (10) [20e22]
29.68, 29.65, 29.3, 28.7, 25.9, 22.6, 14.1. FT-IR (KBr, cmꢁ1): 2910,
2850, 1497, 1467, 1321, 1197, 855.
Prepared according to our reported procedure. Oily liquid at
room temperature; yield: 84%. 1H NMR (CDCl3, 400 MHz):
d
¼ 7.4
(d, 2H, J ¼ 9.0 Hz), 6.8 (d, 2H, J ¼ 9.0 Hz), 4.0 (t, 2H, J ¼ 6.6 Hz), 3.0 (s,
2.2.17. 5,6-Bis(dodecyloxy)-2,1,3-benzoxadiazole (17a)
1H), 1.8 (m), 1.3 (m), 0.9 (t, 6H, J ¼ 7.0 Hz). 13C NMR (CDCl3, 50 MHz)
Recrystallized from ethanol to furnish 17a as off-white solid;
d
: 160.1, 134.0, 115.0, 114.7, 84.3, 76.2, 68.5, 32.6, 30.3, 30.0, 29.8,
yield: 77%, m.p. ¼ 107.3e108.8 ꢀC. 1H NMR (CDCl3, 400 MHz):
26.6, 23.3, 14.6. FT-IR (KBr, cmꢁ1): 3318, 2923, 2854, 2109, 1887,
1607, 1506, 1469, 1289, 1249, 1170, 1108, 1026, 831.
d
¼ 6.8 (s, 2H), 4.1 (t, 4H, J ¼ 6.6 Hz), 1.9 (m, 4H), 1.3 (br), 0.9 (t, 6H,
J ¼ 7.0 Hz). FT-IR (KBr, cmꢁ1): 2913, 2847, 1502, 1471, 1318, 1202,
848. CHN: Expected C30H52N2O3: C 73.72, H 10.72, N 5.73. Found: C
73.72, H 10.69, N 5.70.
2.2.11. 1,2-Bis(dodecyloxy)-4-ethynylbenzene (11)
Greenish
off-white
crystalline
solid;
yield:
¼ 7.1 (dd, 1H,
94%,
m.p. ¼ 37.0e39.2 ꢀC. 1H NMR (CDCl3, 400 MHz):
d
2.2.18. 5,6-Dimethoxy-2,1,3-benzoxadiazole (17b)
J ¼ 8.2 Hz, J4 ¼ 2.0 Hz), 7.0 (d, 1H, J4 ¼ 2.0 Hz), 6.8 (d, 1H, J ¼ 8.4 Hz),
Recrystallized from methanol. Yellow needle-like crystals; yield:
4.0 (m, 4H), 3.0 (s, 1H), 1.8 (m, 4H), 1.3 (br), 0.9 (t, 6H, J ¼ 7.0). 13C
81%, m.p. ¼ 195.0e197.0 ꢀC. 1H NMR (CDCl3, 400 MHz):
d
¼ 6.9 (s,
NMR (CDCl3, 100.6 MHz)
d
: 150.3, 148.8, 125.7, 117.3, 114.3, 113.3,
2H), 4.0 (s, 6H). 13C NMR (CDCl3, 100.6 MHz)
d: 155.4, 146.7, 90.7,
84.2, 75.6, 69.5, 69.3, 32.17, 29.9, 29.6, 26.2, 22.9, 14.4. FT-IR (KBr,
cmꢁ1): 3315, 2925, 2854, 2108, 1599, 1511, 1469, 1416, 1262, 1135,
1022, 853, 805.
56.6. FT-IR (KBr, cmꢁ1): 3146, 3082, 3069, 2995, 2943, 2847, 2442,
1635, 1544, 1521, 1447, 1368, 1244, 1224, 1178, 1001, 854. CHN:
Expected C8H8N2O3: C 53.33, H 4.48, N 15.55. Found: C 53.30, H
4.50, N 15.56.
2.2.12. 1,2-Bis(dodecyloxy)benzene (13a)
The reaction mixture was heated under reflux at 90 ꢀC overnight.
Work up: The reaction mixture was first filtered under vacuum to
remove K2CO3. Water (300 mL) was added to the filtrate to remove
DMFand the product extracted with CH2Cl2 (3 ꢂ100 mL), dried over
MgSO4, concentrated under reduced pressure and the resulting
crude product was recrystallized in ethanol furnishing the pure
3. Results and discussions
3.1. Synthesis and characterization
The synthetic strategy to obtain the target compounds (1-6)
utilized Sonogashira cross-coupling [25] of the separately prepared