168
X. Zheng et al. / Journal of Fluorine Chemistry 123 (2003) 163–169
(d, 1H, J ¼ 6:50 Hz, H-a), 7.58 (m, 1H, H-4), 7.14 (t, 2H,
J ¼ 8:40 Hz, H-3,5); HRMS, m/z (%): 344 (74, Mþ), 253
(100), 191 (36), 163 (15), 141 (55), 113 (11); HRMS Calcd.
for C14H5C12F3N2O: 343.9731. Found: 343.9731.
3.4.9. 2,5-bis(2,6-Difluorophenyl)-1,3,4-oxadiazole (D9)
White needle crystals: yield (95%), mp: 205–206 8C. 1H
NMR (CDCl3) d: 7.56 (m, 2H, Ar 4-H), 7.13 (t, 4H,
J ¼ 8:48 Hz, Ar 3-H). EIMS, m/z (%): 294 (100, Mþ),
238 (52), 237 (47), 141 (96), 113 (19); HRMS Calcd. for
C14H6F4N2O: 294.0416. Found: 294.0368.
3.4.4. 2-(2-Bromophenyl)-5-(2,4-dichloro-
5-fluorophenyl)-1,3,4-oxadiazole (D4)
White needle crystals: yield (92%), mp: 157 8C. IR (KBr)
n: 3080, 3070, 3060, 1600, 1460, 1420, 1280, 1250, 1120,
3.4.10. 2,5-bis(2-Fluorophenyl)-1,3,4-oxadiazole (D10)
White needle crystals: yield (90%), mp: 163–164 8C
(180–185 8C [9]). IR (KBr) n: 1620, 1590, 1560, 1470,
1200, 1100, 900, 770, 740, 730, 680, 540 cmÀ1; H NMR
1
(500 MHz, CDCl3) d: 8.06 (dd, 1H, J1 ¼ 7:79 Hz,
J2 ¼ 1:41 Hz, H-6), 7.97 (d, 1H, J ¼ 9:00 Hz, H-b), 7.80
(d, 1H, J ¼ 7:89 Hz, H-a), 7.67 (d, 1H, J ¼ 6:52 Hz, H-3),
7.51 (t, 1H, J ¼ 7:28 Hz, H-4), 7.45 (m, 1H, H-5). HRMS,
m/z (%): 386 (61, Mþ), 295 (19), 251 (66), 191 (37), 183
(56), 163 (14), 155 (14); EIMS Calcd. for C14H6BrCl2FN2O:
385.9025. Found: 385.9026.
1260, 1230, 1120, 1060, 1040, 820, 770, 750 cmÀ1
.
GC–MS: m/z 258 (Mþ). HRMS Calcd. for C14H8F2N2O:
258.0605. Found: 258.0644.
3.4.11. 2,5-bis(2-Bomorophenyl)-1,3,4-oxadiazole (D11)
White needle crystals: 0.96 g (yield: 59%), mp: 141–
142 8C (240–250 8C [10]). IR (KBr) n: 1595, 1570, 1540,
1470, 1450, 1430, 1020, 780, 760, 740 cmÀ1 GC–MS:
m=z ¼ 278 (Mþ). HRMS Calcd. for C14H8Br2N2O:
377.0981. Found: 377.0957.
3.4.5. 2-(2-Chlorophenyl)-5-(2,4-dichloro-
5-fluorophenyl)-1,3,4-oxadiazole (D5)
Shallow yellow powder: yield (96%), mp: 147–148 8C. IR
(KBr) n: 3080, 1530, 1460, 1280, 1100, 900, 770, 740 cmÀ1
;
3.4.12. 2,5-bis(2-Chloro-4,5-difluorophenyl)-
1,3,4-oxadiazole (D12)
1H NMR (500 MHz, CDCl3): d ¼ 8:12 (dd, 1H,
J1 ¼ 7:83 Hz, J2 ¼ 1:70 Hz, H-6), 7.97 (d, 1H,
J ¼ 9:03 Hz, H-b), 7.67 (d, 1H, J ¼ 4:67 Hz, H-a), 7.60
(dd, 1H, J1 ¼ 7:95 Hz, J2 ¼ 1:00 Hz, H-3), 7.52 (td, 1H,
J1 ¼ 7:68 Hz, J2 ¼ 1:71 Hz, H-4), 7.46 (m, 1H, H-S).
EIMS, m/z (%): 342 (68, Mþ), 251 (100), 191 (51), 163
(17), 139 (88), 111 (15); EIMS Calcd. for C14H6Cl3FN2O:
341.9530. Found: 341.9518.
White needle crystals: yield (95%), mp: 163–164 8C. IR
(KBr) n: 3040, 1595, 1560, 1480, 1430, 1310, 1200, 900, 890,
800, 740 cmÀ1; 1H NMR (500 MHz, CDCl3) d: 8.00 (dd, 2H,
J1 ¼ 10:25 Hz, J2 ¼ 8:04 Hz, H-6), 7.46 (dd, 2H,
J1 ¼ 9:47 Hz, J2 ¼ 6:48 Hz, H-3); EIMS, m/z (%): 362
(62, Mþ), 306 (4), 271 (65), 175 (100), 147 (34), 112 (5),
97 (4); HRMS Calcd. for C14H4C12F4N2O: 361.9637. Found:
361.9644.
3.4.6. 2-(2-Chloro-4,5-difluorophenyl)-5-
(2,4-dichloro-5-fluorophenyl)-1,3,4-oxadiazole (D6)
White needle crystals: yield (93%), mp: 178 8C. IR (KBr)
n: 3100, 3050, 1600, 1550, 1480, 1460, 1430, 1195, 1120,
3.4.13. 2,5-bis(2,4,5-Trifluoro-3-methoxyphenyl)-
1,3,4-oxadiazole (D13)
White needle crystals: yield (93%), mp: 74 8C. IR (KBr) n:
3430, 3060, 2960, 1550, 1500, 1480, 1100, 1320, 1200, 1100,
990, 950, 940 cmÀ1; 1H NMR (CDCl3/TMS) d: 7.68 (m, 2H,
H-6), 4.14 (s, 6H, OCH3). EIMS, m/z (%): 390 (100, Mþ), 344
(11), 319 (16), 303 (17), 189 (75), 161 (9), 146 (6); HRMS
Calcd. for C16H8F6N2O3: 390.0439. Found: 390.0479.
1100, 900, 890, 800, 750, 740 cmÀ1; H NMR (500 MHz,
1
CDCl3) d: 8.02 (dd, IH, J1 ¼ 7:97 Hz, J2 ¼ 2:24 Hz, H-6),
7.96 (d, 1H, J ¼ 8:98 Hz, H-b), 7.68 (d, 1H, J ¼ 6:41 Hz,
H-a), 7.46 (dd, 1H, J1 ¼ 9:56 Hz, J2 ¼ 7:00 Hz, H-3);
EIMS, m/z (%): 378 (48, Mþ), 322 (4), 287 (55), 191
(64), 175 (100), 163 (15), 147 (18), 128 (5); HRMS Calcd.
for C14H4Cl3F3N2O: 377.9341. Found: 377.9315.
Acknowledgements
3.4.7. 2,5-bis(2,3,4,5,6-Pentafluorophenyl)-
1,3,4-oxadiazole (D7)
White needle crystals: yield (74%), mp: 191 8C (156–
158 8C [8]). IR (KBr) n: 1650, 1530, 1510, 1100, 1000, 980,
850 cmÀ1. GC–MS: m=z ¼ 402 (Mþ). HRMS Calcd. for
C14F10N2O: 401.9851. Found: 401.9827.
Financial support from Shanghai Foundation of Science
and Technology (023912001; 02419238) and Ministry of
Science and Technology (2001AA235011) are gratefully
acknowledged.
References
3.4.8. 2,5-bis(2,4,5-Trifluorophenyl)-1,3,4-oxadiazole (D8)
White needle crystals: yield (93%), mp: 188 8C. IR (KBr)
n: 3050, 1570, 1495, 1470, 1370, 1200, 1160, 1110, 1100,
[1] J.P. Arrington, L.L. Wade, US Patent 4,215,129 (1980).
[2] X. Qian, R. Zhang, J. Chem. Tech. Biotechnol. 67 (1996) 124–130.
[3] X. Qian, R. Zhang, G. Song, H. Yu, Chin. Patent 91,1,16834,8 (1999).
[4] X. Qian, J. Tang, W. Chen, R. Zhang, Chem. J. Chin. Univ. 15 (1994)
224–227.
920, 900, 810 cmÀ1; H NMR (500 MHz, CDCl3) d: 8.01
1
(m, 2H, H-6), 7.18 (m, 2H, H-3). EIMS, m/z (%): 330 (100,
Mþ), 256 (52), 255 (47), 159 (96), 131 (19).