Page 5 of 8
RSC Advances
DOI: 10.1039/C4RA11218K
MHz, CDCl3) 7.93ꢀ7.91(d, 1H, J: 4Hz), 7.41ꢀ7.37(t, 1H, J: 8Hz),
7.32ꢀ7.27(m, 4H), 7.04ꢀ6.99(m, 3H), 5.33(s, 2H), 2.69(s, 3H).;
δC (100 MHz, CDCl3) 165.92, 161.80, 157.52, 138.52, 131.68,
131.39, 129.64, 129.04, 126.09, 122.50, 122.09, 114.81, 59.85,
7.56(s, 1H, J: 4Hz), 7.34(s, 1H), 7.25ꢀ7.17(m, 3H), 6.97ꢀ6.93(t,
1H, J: 8Hz), 6.90ꢀ6.88(d, 1H, J; 8Hz), 5.25(s, 2H).; δC (100
MHz, CDCl3) 161.22, 160.54, 154.68, 131.53, 130.50, 130.08,
128.35, 128.25, 127.84, 124.94, 122.04, 121.02, 116.33, 115.68,
5
21.96; IR νmax (film): 3436, 2957, 2921, 1601, 1542, 1495, 70 63.99; IR νmax (film): 3093, 2926, 2846, 1733, 1641, 1585,
1220, 1042, 748, 725 cmꢀ1; MS (EI) m/z 267.4 (M+H +).
1452, 1206, 1008, 851, 750, 721cmꢀ1; MS (EI) m/z 283 (M+H +)
2-(2H-chromen-3-yl)-5-(benzyl)-1,3,4-oxadiazole (9c): Gummy
2-[(2-methoxyphenoxy)methyl]-5-(o-toluoyl)-1,3,4-oxadiazole
(3j): Offꢀwhite solid; yield 0.23 g (0.77 mmole, 76 %); M.R: 78ꢀ
liquid; yield 0.23 g (0.71 mmole, 75%); δH (400 MHz, CDCl3)
10 82 °C ; δH (400 MHz, CDCl3) 7.94ꢀ7.92(d, 1H, J: 8Hz), 7.41ꢀ 75 7.35ꢀ7.29(m, 5H), 7.21ꢀ7.19(d, 2H, J: 4Hz), 7.12ꢀ7.10(d, 1H, J:
7.38(t, 1H, J: 6Hz), 7.32ꢀ7.26(m, 2H), 7.11ꢀ7.09(d, 1H, J: 8Hz),
7.03ꢀ6.99(t, 1H, J: 6Hz), 6.92ꢀ6.87(m, 2H), 5.38(s, 2H), 3.85(s,
3H), 2.67(s,3H).; δC (100 MHz, CDCl3) 165.83, 161.96, 150.05,
146.79, 138.46, 131.61, 131.28, 129.04, 126.02, 123.34, 122.53,
8Hz),6.94ꢀ6.92(t, 1H, J: 4Hz), 6.87ꢀ6.85(d, 1H, J: 8Hz), 5.18(s,
2H), 4.32(s, 2H).; δC (100 MHz, CDCl3) 165.09, 162.40,
154.61, 133.70, 131.44, 129.32, 128.97, 128.79, 127.74,127.63,
121.97, 120.91,116.27, 115.87, 63.96, 31.86; IR νmax (film):
15 120.83, 116.02, 112.16, 61.46, 55.77, 21.93; IR νmax (film): 80 3430, 2923, 2853, 1641, 1624, 1503, 1275, ,1261, 1122, 1018,
3062, 2921, 2582, 1591, 1507, 1256, 1213, 10165, 729 cmꢀ1; MS
750 cmꢀ1; MS (EI) m/z 291.3 (M+H +).
(EI) m/z 297.2 (M+H +).
2-(2H-chromen-3-yl)-5-(m-toluoyl)-1,3,4-oxadiazole (9d)
:
2-(o-toluoyl)-5-(4-pyridyl)-1,3,4-oxadiazole (3k) : Pale yellow
White solid; yield 0.25 g (0.79 mmole, 83%); M.R: 112ꢀ116°C;
20 solid; yield 0.3 g (1.26 mmole, 87 %); M.R: 128ꢀ131°C ; δH 85 δH (400 MHz, CDCl3) 7.95ꢀ7.88(m, 2H), 7.41ꢀ7.30(m, 3H), 7.22ꢀ
(300 MHz, CDCl3) 8.86ꢀ8.84(d, 2H, J: 3Hz), 8.06ꢀ8.04(d, 1H, J:
6Hz), 8.00ꢀ7.98(d, 2H, J: 3Hz), 7.47ꢀ7.45(d, 1H, J: 6Hz), 7.41ꢀ
7.38(d, 3H, J: 3Hz), 2.78(s, 3H).; δC (100 MHz, CDCl3) 165.75,
162.33, 150.92, 138.74, 131.95, 131.74, 131.06, 129.11, 126.30,
7.17(m, 2H), 6.97ꢀ6.93(t, 1H, J: 8Hz), 6.90ꢀ6.88(d, 1H, J: 8Hz),
5.27(s, 2H), 2.44(s, 3H).; δC (100 MHz, CDCl3) 164.41, 161.68,
154.65, 138.99, 132.73, 132.46, 131.44, 128.97, 128.29, 127.64,
127.52, 127.40, 124.19, 124.05, , 123.82, 123.48, 122.01, 121.04,
25 122.43, 120.31, 22.11; IR νmax (film): 3431, 3035, 2924, 2348, 90 116.30, 115.98, 64.02, 21.30;IR νmax (film): 3434, 3053, 2921,
1605, 1535, 1458, 1254, 1059, 728 cmꢀ1; MS (EI) m/z 238.1
2852, 1640, 1522, 1468, 1454, 1210, 1121, 1031, 996, 888, 750
(M+H +).
cmꢀ1; MS (EI) m/z 291.2 (M+H +).
2-(1H-indol-3-ylmethyl)-5-(o-toluoyl)-1,3,4-oxadiazole (3l) : Off
2-(2H-chromen-3-yl)-5-(o-toluoyl)-1,3,4-oxadiazole (9e): White
30 white solid; yield 0.26 g (0.9 mmole, 86 %); M.R: 138ꢀ141 °C; 95 solid; yield 0.27 g (0.83 mmole, 88%); M.R: 116ꢀ120 °C; δH
δH (400 MHz, CDCl3) 8.52(brs, 1H), 7.83ꢀ7.81(d, 1H, J: 8Hz),
7.70ꢀ7.68(d, 1H, J: 8Hz), 7.35ꢀ7.32(m, 2H), 7.27ꢀ7.21(m, 2H),
7.20ꢀ7.11(m, 3H), 4.40(s, 2H), 2.62(s, 3H).; δC (100 MHz,
CDCl3) 165.33, 165.14, 138.19, 136.18, 131.57, 130.97, 128.82,
(400 MHz, CDCl3) 8.01ꢀ7.99(d, 1H, J: 8Hz), 7.45ꢀ7.41(t, 1H, J:
8Hz), 7.37ꢀ7.33(m, 3H), 7.26ꢀ7.22(m, 1H), 7.19ꢀ7.18(d, 1H, J:
4Hz), 6.98ꢀ6.94(t, 1H, J: 8Hz), 6.92ꢀ6.90(d, 1H, J: 8Hz), 5.29(s,
2H), 2.74(s, 3H).; δC (100 MHz, CDCl3) 164.52, 161.31, 154.67,
35 126.77, 125.98, 123.16, 122.95, 119.75, 118.55, 111.36, 108.06, 100 138.61, 131.82, 131.46, 131.38, 131.15, 129.01, 128.94, 128.31,
22.10; IR νmax (film): 3435, 2921, 1604, 1534, 1434, 1260,
127.64, 126.17, 122.70, 122.01, 121.04, 116.31, 115.99, 64.03,
22.18; IR νmax (film): 3435, 2922, 2837, 1642, 1604, 1484,
1453, 1210, 1121, 1031, 889, 750, 727 cmꢀ1; MS (EI) m/z 291.2
(M+H +).
1018, 722 cmꢀ1; MS (EI) m/z 290.2 (M+H +).
5.1. General procedure for the Synthesis of chromene
40 substituted-1,3,4-oxadiazloes (9a-r)
105
To a solution of chromene carboxylic acidhydrazide (7) (1.3
mmol) in dioxane (4 ml) was added 10ꢀcamphorsulfonic acid
(0.065 mmol) followed by acid chloride (8) (1.3 mmol), the
resulted mixture was heated at 100oC for 16h. Then the reaction
2-(2H-chromen-3-yl)-5-cyclopropyl-1,3,4-oxadiazole(9f):
Gummy material ; yield 0.19 g (0.71 mmole, 75 %); δH (400
MHz, CDCl3) 7.22ꢀ7.21(d, 1H, J: 4Hz), 7.18(s, 1H), 7.15ꢀ7.13(d,
1H, J: 8Hz), 6.90ꢀ6.87(d, 1H, J: 12Hz), 5.20(s, 1H), 2.22ꢀ2.18(m,
45 mixture was evaporated under vacumm, added saturated Na2CO3 110 1H), 1.25ꢀ1.20(d, 4H,J: 5Hz).; δC (100 MHz, CDCl3) 131.29,
(10 ml) .then extracted into diethyl ether. Then the resulted
organic layers were dried over Na2SO4 and distilled in vacumm to
obtain 1,3,4ꢀoxadiazole (9a-r) 75ꢀ92% without further
purification.
128.19, 126.93, 121.97, 121.04, 120.85, 116.27, 115.94, 64.02,
29.68, 8.67, 6.48; IR νmax (film): 3442, 2923, 2857, 1636, 1456,
1275, 1261. 1019, 750 cmꢀ1; MS (EI) m/z 241.3 (M+H +).
50
115 2-(2H-chromen-3-yl)-5-(3-fluoro-4-methyl-phenyl)-1,3,4-
oxadiazole (9g): Pale yellow solid; yield 0.19 g (0.81 mmole, 86
%); M.R: 185ꢀ188°C; δH (400 MHz, CDCl3) 7.88ꢀ7.86(d, 1H, J:
8Hz), 7.83ꢀ7.80(dd, 1H, J: 4Hz), 7.35(s, 1H), 7.27ꢀ7.23(m, 1H),
7.20ꢀ7.18(d, 1H, J: 8Hz), 7.10ꢀ7.06(t, 1H, J: 8Hz), 6.99ꢀ6.95(t,
2-(2H-chromen-3-yl)-5-(4-fluorophenyl)-1,3,4-oxadiazole (9a):
Offꢀwhite solid; yield 0.27 g (0.84 mmole, 88%); M.R: 118ꢀ122
°C ; δH (400 MHz, CDCl3) 7.93ꢀ7.91(d, 1h, J:8Hz), 7.82ꢀ7.79(d,
1H, J: 12Hz), 7.54ꢀ7.49(q, 1H, J: 6.3 Hz), 7.39(s, 1H), 7.29ꢀ
55 7.19(m, 2H), 6.99ꢀ6.96(t, 1H, J: 6Hz), 6.92ꢀ6.90(d, 1H, J:12Hz), 120 1H, J: 8Hz), 6.92ꢀ6.90(d, 1H, J: 8Hz), 5.27(s, 2H), 3.98(s, 3H).;
5.28(s, 2H).; δC (100 MHz, CDCl3) 164.08, 163.25, 162.02,
161.61, 154.72, 131.66, 130.92, 128.41, 128.22, 125.55, 122.79,
122.08, 120.94, 119.09, 118.88, 116.37, 115.70, 114.17, 113.93,
63.96, 29.67; IR νmax(film): 3436, 2924, 2854, 1744, 1640,
δC (100 MHz, CDCl3) 163.31, 161.61, 154.67, 153.50, 151.03,
150.89, 150.87, 131.51, 128.32, 127.69, 123.84, 122.04, 121.01,
116.32, 115.36, 114.96, 114.74, 113.47, 63.99, 56.32; IR νmax
(film): 3437, 2924, 2852, 2601, 1744, 1640, 1623, 1503,
60 1604, 1455, 1211, 1123, 1033, 753, 726 cmꢀ1; MS (EI) m/z 295.3 125 1454,1284, 1017, 883, 745 cmꢀ1; MS (EI) m/z 325.2 (M+H2O +).
(M+H+)
2-(6-chloro-2H-chromen-3-yl)-5-(4-ethoxyphenyl)-1,3,4-
oxadiazole (9h): Offꢀwhite solid; yield 0.27 g (0.75 mmole,
2-(2H-chromen-3-yl)-5-(thiophen-2-yl)-1,3,4-oxadiazole (9b):
pale yellow solid; yield 0.23 g (0.75 mmole, 79%); M.R: 181ꢀ
85%); M.R: 174ꢀ176 °C ; δH (300 MHz, CDCl3) 88.04ꢀ8.01(d,
65 184 °CδH (400 MHz, CDCl3) 77.82ꢀ7.81(d, 1H,J; 4Hz), 7.57ꢀ 130 2H, J: 4.5 Hz), 7.20ꢀ7.15(m, 2H), 7.02ꢀ6.99(d, 2H, J: 4.5Hz),
This journal is © The Royal Society of Chemistry [year] Journal Name, [year], [vol], 00–00 |
5