Month 2019
Design and Synthesis of Novel Organic Luminescent Materials Based on
Pyrazole Derivative
Anal. Calcd for C9H8Br2N2: C, 35.80; H, 2.00; Br, 52.92; N,
9.28. Found: C, 35.76; H, 1.98; Br, 52.51; N, 9.23.
Synthesis of 4-bromo-1-(2-bromobenzyl)-1H-pyrazole (4).
1-(40-Benzhydryl-[1,10-biphenyl]-4-yl)-4-(4-
benzhydrylphenyl)-1H-pyrazole (1b).
Yield:
59%.
mp = 238–240°C. 1H NMR (400 MHz, DMSO-d6,
δ, ppm): 9.03 (s, 1H), 8.23 (s, 1H), 8.01 (m, 3H),
7.86 (m, 3H), 7.74 (t, J = 8.1 Hz, 3H), 7.41
(dd, J = 7.9 Hz, 5H), 7.15 (m, 15H). 13C NMR
(101 MHz, DMSO-d6, δ, ppm):147.6, 147.5, 147.3,
140.3, 141.5, 139.0, 138.9, 137.8, 133.5, 130.1, 130.0,
128.0, 127.6, 127.5, 127.0, 124.6, 124.5, 124.4, 124.1,
123.8, 123.4, 119.2, 119.0. Anal. Calcd for C45H34N4:
C, 85.68; H, 5.43; N, 8.88. Found: C, 85.67; H, 5.42;
4-Bromo-1H-pyrazole (1.48 g, 10.00 mmol) was added
to DMF (60 mL) at room temperature. It was stirred for
30 min, and to this solution was then added 2-Bromobenzyl
bromide (4.30 g, 70.00 mmol) and K2CO3 (8.00 g,
70.00 mmol). The reaction temperature was controlled at
about 50°C. The mixture was stirred at this temperature for
3–5 h and then poured into distilled water (200 mL). The
precipitate was collected by filtration, washed with
water (3 × 100 mL), and air-dried. The product was
recrystallized from ethanol to give yellow solid 2.92 g.
N, 8.84.
1-([1,10-Biphenyl]-2-ylmethyl)-4-phenyl-1H-pyrazole (2a).
Yield: 73%. mp = 251–254°C. 1H NMR (400 MHz,
DMSO-d6, δ, ppm): 7.54 (d, J = 7.2 Hz, 2H), 7.49
(q, 1H,), 7.37 (m, 4H), 7.30 (dd, J = 2.0 Hz, 1H),
7.19 (d, J = 2.1 Hz, 1H), 7.10 (d, J = 2.1 Hz, 1H),
5.31 (s, 2H, -CH2-). 13C NMR (101 MHz, DMSO-d6,
δ, ppm): 147.5, 146.9, 141.0, 139.8, 134.4, 135.1,
131.2, 130.5, 130.4, 130.10, 129.0, 128.4, 127.9,
124.6, 92.0, 53.9. Anal. Calcd for C22H18N2: C,
85.13; H, 5.85; N, 9.03. Found: C, 85.10; H, 5.89;
1
Yield: 88%. mp = 154–157°C. H NMR (400 MHz,
DMSO-d6, δ, ppm): 8.09 (s, 1H), 7.67 (d, J = 8.0 Hz,
1H,), 7.62 (s, 1H), 7.39 (t, J = 1.9 Hz, H), 7.29 (t,
J = 1.9 Hz, 1H), 6.97(d, J = 8.9 Hz, 1H), 5.41(s, 2H,
–CH2). 13C NMR (101 MHz, DMSO-d6, δ, ppm)
:140.24, 136.37, 133.15, 131.57, 130.44, 130.28, 128.58,
122.84, 92.48, 55.78. Anal. Calcd for C10H8Br2N2: C,
38.01; H, 2.55; Br, 50.57; N, 8.87. Found: C, 37.96; H,
2.49; Br, 50.51; N, 8.83.
General procedure for synthesis of 1-([1,10-biphenyl]-2-
ylmethyl)-4-phenyl-1H-pyrazole (1a); 1-(40-benzhydryl-[1,10-
biphenyl]-4-yl)-4-(4-benzhydrylphenyl)-1H-pyrazole (1b); 1-
([1,10-biphenyl]-2-ylmethyl)-4-phenyl-1H-pyrazole (2a); 1-((40-
(naphthalen-1-yl)-[1,10-biphenyl]-2-yl)methyl)-4-(4-
N, 9.05.
1-((40-(Naphthalen-1-yl)-[1,10-biphenyl]-2-yl)methyl)-4-(4-
(naphthalen-1-yl)phenyl)-1H-pyrazole (2b).
Yield: 77%.
mp = 165–167°C. 1H NMR (400 MHz, DMSO-d6, δ,
ppm): 8.31 (s, 1H), 8.20 (s, 1H), 8.04 (m, 12H), 7.78
(dd, J = 9.3 Hz, 4H), 7.60 (d, J = 8.2 Hz, 2H), 7.54
(m, 6H), 7.43 (m, 4H), 7.22(d, J = 1.8 Hz, 2H), 5.42
(s, 2H, –CH2–). 13C NMR (101 MHz, DMSO-d6, δ,
ppm): 140.9, 139.6, 137.8, 137.2, 134.9, 133,8, 132.8,
132.6, 132.2, 130.4, 130.3, 129.1, 129.0, 128.9, 128.7,
128.6, 128.4, 128.3, 128.0, 127.9, 127.7, 127.4, 126.9,
126.8, 126.6, 126.4, 126.0, 125.8, 125.3, 125.1, 121.8,
53.5. Anal. Calcd for C42H30N2: C, 89.65; H, 5.37; N,
(naphthalen-1-yl)phenyl)-1H-pyrazole
(2b);
20-((4-(4-
(diphenylamino)phenyl)-1H-pyrazol-1-yl)methyl)-N,N-
diphenyl-[1,10-biphenyl]-4-amine (2c). The reaction mixture
containing intermediate 1 (289 mg, 1 mmol), the
corresponding phenylboronic acid for A1, [4-
(diphenylamino)phenyl]-boronic acid for A2, 4-(1-
naphthyl)phenyl-boronic acid for A3 (1.1 mmol), toluene
(10 mL), H2O (5 mL), K2CO3 (2 M, 5 mmol), and Pd
(PPh3)4 (28 mg, 0.02 mmol) was refluxed under nitrogen
atmosphere reacted 6 h. Upon cooled to room temperature
and diluted by water (20 mL), the reaction mixture was
separated into organic and aqueous layer; thereafter, it was
extracted with dichloromethane (3 × 20 mL). After the
combined organic layers were washed with brine (50 mL),
dried over anhydrous magnesium sulfate, and filtered, the
solvent was removed under reduced pressure. Then, the
residue was isolated by column chromatography over
silica using n-Hexane/ethyl acetate (10:1) as eluent to give
pure products as white solids.
4.98. Found: C, 89.55; H, 5.47; N, 4.93.
20-((4-(4-(Diphenylamino)phenyl)-1H-pyrazol-1-yl)methyl)-
N,N-diphenyl-[1,10-biphenyl]-4-amine (2c).
Yield: 78%.
mp: 211–213°C. 1H NMR (400 MHz, DMSO-d6, δ,
ppm): 8.27 (d, J = 7.7 Hz, 4H,), 7.88 (d, J = 8.4 Hz, 4H),
7.73 (d, J = 8.4 Hz, 4H), 7.47 (q, J = 7.7 Hz, 8H), 7.31
(t, J = 7.7 Hz, 4H), 7.26 (s, 2H), 7.08 (d, J = 2.0 Hz,
2H), 5.46(s, 4H, –CH2–). 13C NMR (101 MHz,
DMSO-d6, δ, ppm):147.5, 146.9 141.0, 139.8, 134.4,
134.1, 131.2, 130.5, 130.4, 130.1, 128.9, 128.4, 127.9,
124.7, 123.7, 123.0, 92.6, 53.9. Anal. Calcd for
C46H36N4: C, 85.68; H, 5.63; N, 8.69. Found: C, 85.58;
H, 5.67; N, 8.64.
1-([1,10-Biphenyl]-4-yl)-4-phenyl-1H-pyrazole (1a). Yield:
68%. mp = 146–148°C. 1H NMR (400 MHz, DMSO-d6, δ,
ppm): 9.12 (s, 1H), 8.31 (s, 1H), 8.06 (d, J = 8.2 Hz, 2H),
7.91 (d, J = 8.0 Hz, 2H), 7.81 (d, J = 8.1 Hz, 4H), 7.55 (m,
5H), 7.34 (t, J = 8.0 Hz, 1H). 13C NMR (101 MHz,
DMSO-d6, δ, ppm): 139.6, 139.3, 138.4, 132.3, 129.5,
128.2, 128.0, 127.1, 127.0, 125.8. Anal. Calcd for
C21H16N2: C, 85.11; H, 5.44; N, 9.45. Found: C, 85.09;
H, 5.40; N, 9.38.
RESULTS AND DISCUSSION
Synthesis. The synthetic procedure of these materials
is shown in Scheme 1. All these five compounds are
synthesized through a Suzuki cross-coupling reaction
Journal of Heterocyclic Chemistry
DOI 10.1002/jhet