NEW PYRAZOLE DERIVATIVES VIA β-KETOSULFONES
337
(54.4), 228 (2.0), 181 (8.1), 141 (10.1), 77 (100). Calcd. for C35H25N5O5S2 (659.75): C,
63.72; H, 3.82; N, 10.62; S, 9.72. Found: C, 63.44; H, 4.67; N, 10.82; S, 9.65.
Ethyl 5-(2-(4-Cyano-1,5-diphenyl-1H-pyrazol-3yl)-2-oxo-1-(phenylsulfonyl)
ethylidene)-4-(4-chlorophenyl)-4,5-dihydro-1,3,4-thiadiazole-2-carboxylate
(18c). Yield (68%), mp 260◦C. IR (cm−1) 2233 (C N), 1757, 1674 (2C O), 1592
(C N); 1H NMR (DMSO-d6) δ 1.26 (t, 3H, J = 7.2 Hz, CH3CH2), 4.38 (q, 2H, J = 7.2
Hz, CH3CH2), 6.98–7.24 (m, 6H, ArH), 7.29–7.42 (m, 10H, ArH), 7.44–7.63 (m, 3H,
ArH); MS m/z (%) 694 (M+, 18.7), 687 (18), 497 (9.0), 463 (14.4), 411 (4.5), 272 (29.7),
180 (15.3), 154 (18.0), 118 (42.3), 77 (100). Calcd. for C35H24N5O5S2Cl (694.19): C,
60.56; H, 3.48; N, 10.09; S, 9.24. Found: C, 60.87; H, 3.35; N, 9.99; S, 9.15.
Synthesis of Thiophene Derivatives 21a–f
A similar procedure to the one that was used for the synthesis of 1,3,4-thiadiazole
is applied here using the appropriate α-haloketone [chloroacetone (19a), ethyl chloroac-
etate (19b), p-bromophenacyl bromide (19c), bromoacetylpyrazole (1), 2-(bromoacetyl)
benzothiazole (19e), and bromoacetylcoumarine (19f)] (2 mmol each) instead of the hy-
drazonoyl halides 15a–c. The formed solid product was filtered off, washed with ethanol,
dried, and finally recrystallized from DMF/EtOH to afford the corresponding thiophene
derivatives 21a–f, respectively.
3-(2-Acetyl-5-(phenylamino)-4-(phenylsulfonyl)thiophen-3-yl)-1,5-diphen
yl-1H-pyrazole-4-carbonitrile (21a). Yield (65%), mp 281–283◦C. IR (cm−1) 3309
1
(NH), 2234 (C N), 1640 (C O); H NMR (DMSO-d6) δ 2.07 (s, 3H, CH3), 7.24–7.28
(m, 4H, ArH), 7.32–7.49 (m, 10H, ArH), 7.73–7.76 (m, 6H, ArH), 9.69 (s, 1H, NH,
D2O-exchangeable); MS m/z (%) 600 (M+, 100), 522 (34.3), 422 (27.4), 272 (15.8), 180
(19.5), 77 (87.5). Calcd. for C34H24N4O3S2 (600.72): C, 67.98; H, 4.03; N, 9.33; S, 10.68.
Found: C, 67.72; H, 4.11; N, 9.01; S, 10.59.
Ethyl
3-(4-Cyano-1,5-diphenyl-1H-pyrazol-3-yl)-5-(phenylamino)-4-
(phenylsulfonyl)-thiophene-2-carboxylate (21b). Yield (63%), mp 211–213◦C. IR
(cm−1) 3299 (NH), 2234 (C N), 1623 (C O); H NMR (DMSO-d6) δ 1.15 (t, 3H, J =
1
7.2 Hz, CH3CH2), 4.14 (q, 2H, J = 7.2 Hz, CH3CH2), 7.26–7.37 (m, 8H, ArH), 7.38–7.5
(m, 7H, ArH), 7.74–7.77 (m, 5H, ArH), 9.6 (s, 1H, NH); MS m/z (%) 631 (M++1, 65.2),
630 (M+, 77.9), 520 (19.3), 494 (28.3), 371 (24.5), 272 (39.0), 180 (14.7), 77 (100). Calcd.
for C35H26N4O4S2 (630.75): C, 66.65; H, 4.15; N, 8.88; S, 10.17. Found: C, 66.86; H,
4.27; N, 8.71; S, 10.30.
3-(2-(4-Bromobenzoyl)-5-(phenylamino)-4-(phenylsulfonyl)thiophen-3-
yl)-1,5-diphenyl-1H-pyrazole-4-carbonitrile (21c). Yield (72%), mp 253–255◦C.
IR (cm−1) 3275 (NH), 2230 (C N), 1672 (C O); 1H NMR (DMSO-d6) δ 6.97–7.13 (m,
4H, ArH), 7.27–7.41 (m, 8H, ArH), 7.43–7.69 (m, 10H, ArH), 7.72 (d, 2H, J = 8.1 Hz,
ArH), 9.82 (s, 1H, NH, D2O-exchangeable); MS m/z (%) 742 (M+, 66.0), 741 (35.9), 676
(19.4), 645 (24.6), 493 (23.0), 371 (11.7), 183 (52.9), 195 (10.2), 77 (100). Calcd. for
C39H25N4O3S2Br (741.69): C, 63.16; H, 4.40; N, 7.55; S, 8.65. Found: C, 63.24; H, 4.37;
N, 7.32; S, 8.57.
3-(3-(4-Cyano-1,5-diphenyl-1H-pyrazol-3-yl)-5-phenylamino-4-(phenylsul
fonyl)-(thiophene-2-carbonyl))-1,5-diphenyl-1H-pyrazole-4-carbonitrile (21d).
1
Yield (65%), mp > 300◦C. IR (cm−1) 3282 (NH), 2232 (C N), 1631 (C O); H NMR
(DMSO-d6) δ 7.22–7.38 (m, 10H, ArH), 7.39–7.46 (m, 10H, ArH), 7.48–7.50 (m, 8H,
ArH), 7.73–7.76 (d, 2H, J = 7.8 Hz, ArH), 9.78 (s, 1H, NH, D2O-exchangeable). Calcd.