230 JOURNAL OF CHEMICAL RESEARCH 2013
3-((1-Methyl-5-oxo-3-phenyl-4,5-dihydro-1H-pyrazol-4-yl)diazenyl)
benzenesulfonic acid (5a): The title compound was synthesised
from 1 (0.870 g, 5 mmol) and 3-aminobenzen sulfonic acid (0.866 g,
5 mmol) following the general method. The reaction mixture was
poured into ice-water and the solid precipitate was filtered and washed
with cold ether to obtain the pure product. Orange solid, yield 0.753 g
(42%), m.p. 260 °C dec. Rf 0.39 (SiO2; ethyl acetate/n-hexane 2:1); 1H
NMR (500 MHz, CD3OD): δ 2.68 (s, 1H, SO2OH), 3.41 (s, 3H, CH3),
3.51 (s, 1H, CH), 7.33–7.51 (m, 5H, ArH), 7.58 (d, J = 7.55 Hz, 1H,
ArH), 7.91 (s, 1H, ArH), 8.01 (d, J = 8.45 Hz, 2H, ArH) ppm; APT
(125 MHz, C5D5N): δ 31.76 (CH3), 33.29 (CH), 115.30 (ArCH),
117.51 (ArCH), 124.50 (ArCH), 127.98 (ArCH), 128.38 (ArC–S),
128.92 (ArCH), 129.45 (ArCH), 129.68 (ArCH), 131.80 (ArC–N),
142.34 (ArC), 154.58 (C=N), 159.27 (C=O) ppm; IR (ATR): ν = 3429
(OH), 1652 (C=O), 1599 (N=N) cm−1; GC-MS (m/z): 360 (M+ + 2),
345, 201, 174, 103, 80, 77; UV (CH3OH, c = 1.86 × 10−4 mol L−1): λmax
(Σ) 204 (7957), 241 (3871), 396 (4194) nm (L mol−1 cm−1). Anal.
Calcd for C16H14N4O4S: C, 53.62; H, 3.94; N, 15.63; S, 8.95. Found:
C, 53.69; H, 4.07; N, 15.52; S 8.88%.
4,4′-(4,4′-Sulfonylbis(4,1-phenylene))bis(1-(4-chlorophenyl)-3-iso-
propyl-1H-pyrazol-5(4H)-one) (6b): The title compound was synthe-
sised from 2 (2.366 g, 10 mmol) and 4,4′-sulfonyldianiline (1,241 g,
5 mmol) following the general method. The crude product was recrys-
tallised in acetone/DMSO (1:2) because of the solubility problem.
Red solid, yield 2.305 g (62%), m.p.>300 °C. Rf 0.74 (SiO2; DMSO);
IR (ATR): ν = 1662 (C=O), 1546 (N=N) cm−1; GC-MS (m/z):
403 (C18H16ClN4O., 22.72), 339 (C18H16ClN4O3. - SO2, 31.81), 296
(C15H19ClN4O.., 20), 221 (C9H5ClN4O., 50.90), 207 (C10H8ClN2O.,
100), 193 (C9H5ClN2O.., 8.18), 111 (C6H4Cl., 15.45), 43 (isopropyl.,
16.36); ESI(−)-MS (m/z): 744 (M−); UV (DMSO): 287.38 (not 100%
soluble) nm. Anal. Calcd for C36H32Cl2N8O4S: C, 58.14; H, 4.34; N,
15.07; S, 4.31. Found: C, 57.98; H, 4.48; N, 15.11; S, 4.39%.
4,4′-(4,4′-Sulfonylbis(4,1-phenylene))bis(3-isopropyl-1-(4-methoxy-
phenyl)-1H-pyrazol-5(4H)-one) (6c): The title compound was synthe-
sised from 3 (2.320 g, 10 mmol) and 4,4′-sulfonyldianiline (1,241 g,
5 mmol) following the general method. The reaction mixture was
poured into ice-water, the solid phase was filtered, then washed with
cold ethanol and ether. Red solid, yield 1.469 g (40%), m.p.>300 °C.
Rf 0.81 (SiO2; ethyl acetate/n-hexane 2:1); 1H NMR (500 MHz,
CDCl3): δ 1.33 (d, J = 6.71 Hz, 12H, CH3), 3.04–3.19 (sep, J =
6.71 Hz, 2H, CH), 3.76 (s, 6H, OCH3), 6.88 (d, J = 8.72 Hz, 4H, ArH),
7.40 (d, J = 8.72 Hz, 4H, ArH), 7.74 (d, J = 8.72 Hz, 4H, ArH), 7.90
(d, J = 8.72 Hz, 4H, ArH), 13.52 (br s, 2H, NH) ppm; APT (125 MHz,
CDCl3): δ 19.67 (CH3), 26.62 (CH), 54.49 (OCH3), 113.12 (ArCH),
114.71 (ArCH), 119.51 (ArCH), 128.51 (C=N–NH), 129.16 (ArCH),
130.03 (ArC), 136.36 (ArC), 144.23 (ArC), 154.78 (ArC), 156.05
(C=N), 156.32 (C=O) ppm; IR (ATR): ν = 1658 (C=O), 1560 (N=N)
cm−1; ESI(−)-MS (m/z): 735 (M− + 1); UV (chloroform, c = 9.08 × 10−5
mol L−1): λmax = 255 (17070), 407 (19273) nm (mol−1 L cm−1). Anal.
Calcd for C38H38N8O6S: C, 62.11; H, 5.21; N, 15.25; S, 4.36. Found:
C, 61.99; H, 5.32; N, 15.11; S, 4.23%.
4,4′-(4,4′-(Ethene-1,2-diyl)bis(4,1-phenylene))bis(1-methyl-3-phenyl-
1H-pyrazol-5(4H)-one) (7a): The title compound was synthesised
from 1 (1.740 g, 10 mmol) and 4,4′-(ethane-1,2-diyl)dianiline dihy-
drochloride (1.416 g, 5 mmol) following the general method. The
reaction mixture was poured into ice-water, the solid was filtered and
then washed with cold ether twice. Red solid, yield 1.451 g (50%),
m.p. 260–261 °C. Rf 0.61 (SiO2; ethyl acetate/n-hexane 1:1); 1H NMR
(500 MHz, CDCl3): δ 3.50 (s, 6H, CH3), 7.23 (d, J = 8.78 Hz, 4H,
ArH), 7.30 (d, J = 8.78 Hz, 4H, ArH), 7.59 (d, J = 8.78 Hz, 2H, =CH),
8.06–8.14 (m, 10H, ArH), 13.80 (br s, 2H, NH) ppm; APT (125 MHz,
CDCl3): δ 28.68 (CH3), 109.01 (ArCH), 114.48 (ArC), 114.50 (ArCH),
126.04 (ArC), 126.11 (ArCH), 127.46 (=CH), 127.54 (C=N–NH),
126.86 (ArCH), 128.71 (ArCH), 133.08 (ArC), 142.97 (C=N), 157.76
(C=O) ppm; IR (ATR): ν = 1651 (C=O), 1550 (N=N) cm−1; ESI(+)-MS
(m/z): 563 [(M+ - 2) - CH3]; UV (CH3OH, c = 1.72 × 10−4 mol L−1): λmax
(Σ) 204 (9593), 252 (7326), 421 (872) nm (L mol−1cm−1). Anal. Calcd
for C34H28N8O2: C, 70.33; H, 4.86; N, 19.30. Found: C, 70.18; H, 4.93;
N, 19.12%.
3-((1-(4-Chlorophenyl)-3-isopropyl-5-oxo-4,5-dihydro-1H-pyrazol-
4-yl)diazenyl)benzenesulfonic acid (5b): The title compound was
synthesised from 2 (1.183 g, 5 mmol) and 3-aminobenzene sulfonic
acid (0.866 g, 5 mmol) following the general method. Crude product
was recrystallised in water/methanol (1:1). Dark yellow solid, yield
1
1.410 g (67%), m.p.>300 °C. Rf 0.76 (SiO2; methanol); H NMR
(400 MHz, d6-DMSO): δ 0.90 (d, J = 6.89 Hz, 6H, CH3), 2.65–2.75
(sep, J = 6.89 Hz, 1H, CH), 6.93–7.08 (m, 6H, ArH), 7.37 (s, 1H,
OH), 7.50 (d, J = 8.78 Hz, 2H, ArH), 13.30 (br s, 1H, NH) ppm; 13
C
NMR (100 MHz, d6-DMSO): δ 20.80 (CH3), 27.15 (CH), 113.17,
117.0, 119.50, 123.24, 126.75, 128.85, 129.24, 129.35, 137.07 (C=N),
141.0, 150.14, 156.26 (C=N), 157.07 (C=O) ppm; IR (ATR): ν = 3444
(OH), 1651 (C=O), 1539 (N=N) cm−1; GC-MS (m/z): 421 (M+), 407,
376, 306, 205, 111, 43; UV (CH3OH, c = 7.89 × 10−4 mol L−1): λmax (Σ)
202 (1719), 255 (1073), 393 (963) nm (L mol−1 cm−1). Anal. Calcd for
C18H17ClN4O4S: C, 51.37; H, 4.07; N, 13.31; S, 7.62. Found: C, 51.31;
H, 4.18; N, 13.17; S, 7.43%.
3-((3-Isopropyl-1-(4-methoxyphenyl)-5-oxo-4,5-dihydro-1H-pyrazol-
4-yl)diazenyl)benzenesulfonic acid (5c): The title compound was
synthesised from 3 (1.160 g, 5 mmol) and 3-aminobenzene sulfonic
acid (0.866 g, 5 mmol) following the general method and was purified
by column chromatography (SiO2; ethyl acetate/n-hexane 1:1). Orange
solid, yield 1.270 g (61%), m.p. 264–265 °C. Rf 0.60 (SiO2; ethyl
1
acetate/n-hexane 1:1); H NMR (500 MHz, CDCl3): δ 1.35 (d, J =
6.91 Hz, 6H, CH3), 3.11–3.19 (sep, J = 6.91 Hz, 1H, CH), 3.77 (s, 3H,
OCH3), 6.97 (d, J = 9.14 Hz, 1H, ArH), 7.03 (d, J = 9.14 Hz, 2H,
ArH), 7.09 (d, J = 2.54 Hz, 1H, ArH), 7.11 (d, J = 2.54 Hz, 1H, ArH),
7.52 (d, J = 2.54 Hz, 1H, ArH), 7.77 (d, J = 9.09 Hz, 2H, ArH), 11.11
(br s, 1H, OH), 13.49 (br s, 1H, NH) ppm;APT (125 MHz, d6-DMSO):
δ 21.44 (CH3), 21.50 (CH), 56.04 (OCH3), 114.29 (ArCH), 114.89
(ArCH), 117.92 (ArCH), 120,69 (ArCH), 122.20 (ArCH), 124.66
(C=N–NH), 126.06 (ArCH), 128.60 (ArC), 130.91 (ArC–NH), 131.73
(ArC), 155.70 (C=N), 157.31 (C=O), 157.50 (ArC–OCH3) ppm; IR
(ATR): ν = 3352 (OH), 1636 (C=O), 1599 (N=N) cm−1; GC-MS (m/z):
417 (M+ + 1), 232, 217, 189, 81, 43; UV (CH3OH, c = 3.20 × 10−4 mol
L−1): λmax (Σ) 204 (5859), 249 (3750), 423 (3125) nm (L mol−1 cm−1).
Anal. Calcd for C19H20N4O5S: C, 54.80; H, 4.84; N, 13.45; S, 7.70.
Found: C, 54.89; H, 4.95; N, 13.11; S, 7.59%.
4,4′-(4,4′-(Ethene-1,2-diyl)bis(4,1-phenylene))bis(1-(4-chlorophenyl)-
3-isopropyl-1H-pyrazol-5(4H)-one) (7b): The title compound was
synthesised from 2 (2.366 g, 10 mmol) and 4,4′-(ethane-1,2-
diyl)dianiline dihydrochloride (1.416 g, 5 mmol) following the gen-
eral method. The solid phase was filtered, the solid phase washed with
cold ethanol and ether to obtain the pure product. Red solid, yield
2.363 g (67%), m.p. 228 °C dec. Rf 0.87 (SiO2; chloroform/n-hexane
1
2:1); H NMR (500 MHz, d6-DMSO): δ 1.27 (d, J = 6.93 Hz, 12H,
CH3), 3.19–3.28 (sep, J = 6.93 Hz, 2H, CH), 7.31 (d, J = 8.83 Hz, 2H,
=CH), 7.36 (d, J = 8.83 Hz, 4H, ArH), 7.52 (d, J = 8.47 Hz, 4H, ArH),
7.57 (d, J = 8.47 Hz, 4H, ArH), 8.14 (d, J = 8.47 Hz, 4H, ArH), 13.02
(br s, 2H, NH) ppm; 13C NMR (125 MHz, d6-DMSO): δ 20.77 (CH3),
29.96 (CH), 118.25, 118.67, 120.18, 125.64, 126.72 (=C), 128.07
(C=N–NH), 128.66, 131.89, 146.62, 149.97, 157.06 (C=N), 160.42
(C=O); IR (ATR): ν = 1651 (C=O), 1539 (N=N) cm−1; ESI(+)-MS
(m/z): 721 (M+ + 15); UV (CH3OH, c = 5.67 × 10−5 mol L−1): λmax (Σ)
235.50 (70546), 269.50 (17777), 323.50 (5943), 511.50 (28536) nm
(mol−1 L cm−1). Anal. Calcd for C38H34Cl2N8O2: C, 64.68; H, 4.86; N,
15.88. Found: C, 64.44; H, 4.98; N, 15.67%.
4,4′-(4,4′-Sulfonylbis(4,1-phenylene))bis(1-methyl-3-phenyl-1H-
pyrazol-5(4H)-one) (6a): The title compound was synthesised from 1
(1.740 g, 10 mmol) and 4,4′-sulfonyldianiline (1,241 g, 5 mmol)
following the general method and was purified by column chromato-
graphy (SiO2; ethyl acetate/n-hexane 2:1). Red solid, yield 1.392 g
1
(45%), m.p.>300 °C. Rf 0.70 (SiO2; ethyl acetate/n-hexane 2:1); H
NMR (500 MHz, CDCl3): δ 3.45 (s, 6H, CH3), 7.39–7.46 (m, 10H,
ArH), 7.87–7.94 (m, 8H, ArH), 13.74 (br s, 2H, NH) ppm; APT
(125 MHz, CDCl3): δ 44.83 (N-CH3), 75.75 (C–N=N), 112.91 (ArCH),
114.92 (ArCH), 126.07 (ArCH), 126.51 (ArCH), 128.72 (ArC),
140.73 (ArC), 144.11 (ArC), 157.51 (C=N), 157.59 (ArC=N), 169.76
(C=O) ppm; IR (ATR): ν = 1733 (C=O), 1556 (N=N) cm−1; ESI(−)-MS
(m/z): 731 [M− + (TFA – H]; UV (CH3OH, c = 2.15 × 10−4 mol L−1):
λmax (Σ) 202 (8418), 257 (2790), 399 (1860) nm (L mol−1cm−1). Anal.
Calcd for C32H26N8O4S: C, 62.12; H, 4.24; N, 18.11; S, 5.18. Found:
C, 62.01; H, 4.29; N, 17.99; S, 5.10.
4,4′-(4,4′-(Ethene-1,2-diyl)bis(4,1-phenylene))bis(3-isopropyl-1-
(4-methoxyphenyl)-1H-pyrazol-5(4H)-one) (7c): The title compound
was synthesised from 3 (2.320 g, 10 mmol) and 4,4′-(ethane-1,2-
diyl)dianiline dihydrochloride (1.416 g, 5 mmol) following the
general method and was purified by column chromatography (SiO2;
ethyl acetate/n-hexane 2:1). Red solid, yield 2.125 g (61%), m.p. 283–
1
284 °C dec. Rf 0.84 (SiO2; ethyl acetate/n-hexane 2:1); H NMR
(TFA: Trifluoroacetic acid).
(500 MHz, CDCl3): δ 1.45 (d, J = 6.93 Hz, 12H, CH3), 3.17–3.25 (sep,