J. Han et al. / Journal of Molecular Structure 937 (2009) 122–130
129
methane were pre-dried and distilled over sodium in benzophe-
none and calcium hydride respectively.
v = 1:3) as an eluent. The reaction product was obtained as off-
white solid in 79% yield. 1H NMR (300 MHz, CDCl3, 25 °C, TMS): d
8.09–7.98 (m, 4H), 7.35 (d, J = 8.7 Hz, 2H), 7.02 (d, J = 8.7 Hz, 2H),
4.04 (t, J = 6.6 Hz, 2H), 2.55 (s, 3H), 1.87–1.78 (m, 2H), 1.53–1.19
(m, 14H), 0.89 (t, J = 6.6 Hz, 3H). 13C NMR (300 MHz, CDCl3, 25 °C,
TMS): 164.4, 163.9, 161.9, 143.6, 128.6, 127.0, 125.9, 120.3,
116.2, 114.9, 77.5, 77.0, 76.6, 68.3, 31.9, 29.6, 29.4, 29.3, 29.2,
26.0, 22.7, 15.0, 14.1. MS (+cESI): 425.54 ([M+H]+). Elemental anal-
ysis (%): calculated for C: 70.72, H: 7.60, N: 6.60; found C: 70.78, H:
7.49, N: 6.49.
4.3. Preparation of 4-methylthiobenzoic acid N0-(4-decyloxbenzoyl)
hydrazide ia
To a round-bottom flask (100 mL) were added 4-methylthio-
benzoic acid (10 mmol, 1.68 g) and thionyl chloride SOCl2
(10 mL), the mixture was refluxed for 5 h to give the corresponding
4-methylthiobenzoyl chloride. Excessive SOCl2 was removed by
vacuum distillation and 4-decyloxybenzoic hydrazide (10 mmol,
2.92 g) dissolved in pyridine (15 mL) was added dropwise to the
as-formed 4-methylthiobenzoyl chloride. The reaction mixture
was stirred at RT for 2 h and then at 70 °C for further 1 h. Crude so-
lid was precipitated by pouring the reaction mixture into distilled
water (50 mL). The crude solid was washed with distilled water
and recrystallized from ethanol. Yield: 80%. 1H NMR (400 MHz,
CDCl3, 25 °C, TMS): d 9.31 (d, J = 4.8 Hz, 1H), 9.19 (d, J = 4.8 Hz,
1H), 7.81 (d, J = 8.4 Hz, 2H), 7.77 (d, J = 8.0 Hz, 2H), 7.27 (d, J =
8.0 Hz, 2H), 6.93 (d, J = 8.8 Hz, 2H), 4.00 (t, J = 6.4 Hz, 2H), 2.52 (s,
3H), 1.80 (m, 2H), 1.46 (m, 2H), 1.27 (m, 12H), 0.88 (t, J = 6.6 Hz,
3H). MS (+cESI): 443.07 ([M+H]+).
4.6. Synthesis of 2-(40-methylthio-4-biphenyl)-5-(4-decyloxyphen-yl)-
1,3,4-thiadiazole 3a
Compound 2-(4-bromophenyl)-5-(4-decyloxyphenyl)-1,3,4-thia-
diazole (1 mmol), 4-methylthiobenzene boronic acid (1 mmol),
KFꢀ2H2O (10 mmol), and Pd(OAc)2 (4
lmol) were mixed and put
into a 10 mL test tube, which was placed into a household micro-
wave oven (Glanz WP800TL23-KL, 800 W) for about 30 s. The test
tube was removed from the microwave oven after the reaction
mixture had been cooled to RT. The crude product was dissolved
in CHCl3 and was purified by silica gel column chromatography
using CH2Cl2/ethyl acetate (v/v = 25:1) as an eluent to afford the
reaction product as off-white solid. Yield: 42%. White solid, yield:
4.4. Synthesis of 2-(4-methylthiophenyl)-5-(4-decyloxyphenyl)-1,3,4-
thiadiazole 1a
88.5%. 1H NMR (300 MHz, CDCl3, 25 °C, TMS):
d 8.06 (d,
J = 8.4 Hz, 2H), 7.96 (d, J = 8.7 Hz, 2H), 7.70 (d, J = 8.4 Hz, 2H),
7.58 (d, J = 8.4 Hz, 2H), 7.36 (d, J = 8.4 Hz, 2H), 7.00 (d, J = 8.7 Hz,
2H), 4.03 (t, J = 6.6 Hz, 2H), 2.54 (s, 3H), 1.87–1.77 (m, 2H), 1.53–
1.21 (m, 14H), 0.89 (t, J = 6.6 Hz, 3H). 13C NMR (300 MHz, CDCl3,
25 °C, TMS): 168.1, 167.1, 161.7, 143.1, 138.9, 136.7, 129.6, 129.3,
128.5, 127.5, 127.5, 127.0, 122.8, 115.2, 68.5, 32.0, 29.7, 29.5,
29.5, 29.3, 26.2, 22.8, 15.9, 14.3. MS (20 eV EI) m/z (I%): 517
(23.80) [M]+. HRMS Calcd for C31H36N2OS2: 516.2269; Found:
516.2269. Elemental analysis (%): calculated for C: 72.05, H: 7.02,
N: 5.42; found C: 71.91, H: 7.18, N: 5.51.
4-Methylthiobenzoic acid N0-(4-decyloxbenzoyl)hydrazide
(1 mmol) and Lawesson’s reagent [2,4-bis-(4-methoxyphenyl)-
1,3-dithia-2,4-diphosphetane-2,4-disulfide] (1.1 mmol) were mixed
and placed into a test tube (10 mL), which was put in a household
microwave oven (Glanz WP800TL23-KL) and radiated at a full
power (800 W). When the mixture turned into a brown liquid,
the microwave irradiation was stopped immediately. The crude
product was purified by silica gel column chromatography using
ethyl acetate/ dichloromethane (v/v = 1:15) as an eluent. Yield:
67%. 1H NMR (300 MHz, CDCl3, 25 °C, TMS): d 8.12–7.99 (m, 4H),
7.35 (d, J = 8.7 Hz, 2H), 7.02 (d, J = 8.7 Hz, 2H), 4.04 (t, J = 6.6 Hz,
2H), 2.55 (s, 3H), 1.87–1.78 (m, 2H), 1.53–1.19 (m, 14H), 0.89 (t,
J = 6.6 Hz, 3H). 13C NMR (300 MHz, CDCl3, 25 °C, TMS): 167.6,
166.8, 161.6, 142.8, 129.4, 128.0, 126.8, 126.1, 122.6, 115.1, 77.5,
77.0, 76.6, 68.3, 31.9, 29.6, 29.4, 29.3, 29.171, 26.0, 22.7, 15.2,
14.1. MS (+cESI): 441.58 ([M+H]+). Elemental analysis (%): calcu-
lated for C: 68.14, H: 7.32, N: 6.36; found C: 68.11, H: 7.51, N: 6.33.
Compound 1b was prepared according to the same procedures
as 1a.
2-(4-Methoxyphenyl)-5-(4-decyloxyphenyl)-1,3,4-thiadiazole
1b: 1H NMR (300 MHz, CDCl3, 25 °C, TMS): d 7.96–7.92 (m, 4H),
7.02–6.97 (m, 4H), 4.02 (t, J = 6.6 Hz, 2H), 3.88 (s, 3H),
1.86–1.77 (m, 2H), 1.55–1.20 (m, 14H), 0.89 (t, J = 6.6 Hz, 3H). 13C
NMR (300 MHz, CDCl3, 25 °C, TMS): d 167.36, 167.17, 161.91,
161.57, 129.51, 129.50, 123.24, 122.93, 115.16, 114.66, 68.43,
55.61, 32.06, 29.72, 29.54, 29.48, 29.32, 26.16, 22.84, 14.27. MS
(20 eV EI) m/z (I%): 425 (82.00) [M]+. HRMS Calcd for C25H32N2O2S:
424.2184; Found: 424.2184. Elemental analysis (%): calculated for
C: 70.72, H: 7.60, N: 6.60; found C: 70.51, H: 7.46, N: 6.66.
Compound 3b was prepared according to the same procedures
as 3a.
2-(40-Methoxy-4-biphenyl)-5-(4-decyloxyphenyl)-1,3,4-thia-
diazole 3b: 1H NMR (400 MHz, CDCl3, 25 °C, TMS): d 8.04 (d,
J = 8.4 Hz, 2H), 7.95(d, J = 8.7 Hz, 2H), 7.67 (d, J = 8.4 Hz, 2H), 7.59
(d, J = 8.7 Hz, 2H), 7.01 (d, J = 8.7 Hz, 2H), 6.96 (d, J = 8.7 Hz, 2H),
4.03 (t, J = 6.6 Hz, 2H), 3.87 (s, 3H), 1.86–1.77 (m, 2H), 1.56–1.15
(m, 14H), 0.89 (t, J = 6.6 Hz, 3H). 13C NMR (400 MHz, CDCl3, 25 °C,
TMS): d 164.70, 164.24, 162.12, 160.00, 144.00, 132.47, 128.82,
127.54, 127.42, 127.25, 122.38, 116.39, 115.14, 114.59, 68.46,
55.55, 32.05, 29.71, 29.53, 29.47, 29.30, 26.16, 22.83, 14.26. MS
(20 eV EI) m/z (I%): 501 (93.40) [M]+. HRMS Calcd for C31H36N2O2S:
500.2497; Found: 500.2497. Elemental analyses (%): calculated for
C: 74.36, H: 7.25, N: 5.59; found C: 74.10, H: 7.54, N: 5.68.
4.7. Synthesis of 2-(40-methylthio-4-biphenyl)-5-(4-decyloxyphenyl)-
1,3,4-oxadiazole 4a
To a round-bottom flask (100 mL) were added 2-(4-bromophe-
nyl)-5-(4-decyloxyphenyl)-1,3,4-oxadiazole (1 mmol), 4-(methyl-
thio)benzeneboronic acid (1 mmol), K2CO3 (5 mmol) and
4.5. Synthesis of 2-(4-methylthiophenyl)-5-(4-decyloxyphenyl)-1,3,4-
Pd(OAc)2 (2 lmol) as a catalyst in a solution mixture of dioxane
oxadiazole 2a
(30 mL) and water (10 mL) refluxed for one hour under nitrogen.
The reaction mixture was evaporated in vacuo, then the solid res-
idue was extracted by CH2Cl2 twice (2 ꢂ 50 mL), then dried with
anhydrous MgSO4, filtered and concentrated at reduced pressure.
The crude product was purified by silica gel column chromatogra-
phy using CH2Cl2/ethyl acetate (v/v = 15:1) as an eluent. Yield: 82%.
White solid, yield: 86.8%. 1H NMR (300 MHz, CDCl3, 25 °C, TMS): d
8.18 (d, J = 8.4 Hz, 2H), 8.08 (d, J = 8.7 Hz, 2H), 7.73 (d, J = 8.4 Hz,
2H), 7.59 (d, J = 8.4 Hz, 2H), 7.35 (d, J = 8.4 Hz, 2H), 7.03 (d,
The intermediate 4-methylthiobenzoic acid N0-(4-dec-
yloxbenzoyl)hydrazide (1 mmol) was added to SOCl2 (5 mL) in
dried benzene (10 mL). The reaction mixture was refluxed for 7 h
and the excessive thionyl chloride and solvent were removed by
vacuum distillation. The crude solid was collected and washed sev-
eral times with distilled water and was further purified by silica gel
column chromatography using ethyl acetate/petroleum ether (v/