ꢂꢁꢁꢁ
E.S. Fondjo et al.: Thiophene containing azo compoundsꢀ
ꢀ257
1618, 1529, 1442 (Nꢀ= ꢀN) cm-1; MS: m/z (%) 313 (13), 347 (10), 493 (100),
414 (1), 444 (1), 494 (26), 495 (14), 555 (6), 617 (6). Anal. Calcd for
C26H17N3O12S4: C, 45.15; H, 2.48; N, 6.08; S, 18.54. Found: C, 45.13; H,
2.46; N, 6.07; S, 18.43. Rf: 0.55.
2000 spectrometer in KBr pellets. The UV-vis spectra were recorded
in tetrahydrofuran (THF) using a Beckman U-640 spectrophotometer.
Combustion analyses were carried out on a CHNS Euro analyzer. EI
mass spectra (70 eV) were measured on a LCQ Classic spectrometer
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from Thermo Fisher Scientific Company. H NMR spectra (750 MHz)
and 13C NMR spectra (187.5 MHz) were recorded in DMSO-d6 on a Bruk-
er AV III instrument. All reagents were purchased from Aldrich and
Fluka and were used without further purification. Starting materials
1a–c were prepared according to literature procedures as published
earlier [11, 12].
2-Amino-5-{2-[3-carboxy-4-(2-hydroxy-1-naphthyl)-2-thienyl]
diazenyl}-4-(2-hydroxyphenyl)-3-thiophenecarboxylic
acid
sulfate (5)ꢀReaction of 1b with the diazonium solution 2a gave
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compound 5 (640 mg, 51%) as brown powder; mp 140°C (dec); H
NMR: δ 7.32 (d, 1H, J ꢀ= ꢀ 7.5 Hz, 3′-H), 7.45 (dd, 1H, J ꢀ= ꢀ 7.0 and 7.5 Hz,
4′-H), 7.32 (dd, 1H, J ꢀ= ꢀ 7.0 and 7.0 Hz, 5′-H), 8.23 (d, 1H, J ꢀ= ꢀ 7.0 Hz,
6′-H), 7.11 (s, 1H, 5″-H), 7.54 (d, 1H, J ꢀ= ꢀ 9.0 Hz, 3″′-H), 8.17 (d, 1H, J ꢀ= ꢀ
9.0 Hz, 4″′-H), 8.09 (d, 1H, J ꢀ= ꢀ 8.0 Hz, 5″′-H), 7.49 (dd, 1H, J ꢀ= ꢀ 7.0 and
7.5 Hz, 6″′-H), 7.70 (dd, 1H, J ꢀ= ꢀ 7.5 and 8.0 Hz, 7″′-H), 8.52 (d, 1H, J ꢀ= ꢀ
8.0 Hz, 8″′-H), 8.08 (D2O-exchangeable, NH2); 13C NMR: δ 154.2 (C-
2), 119.5 (C-3), 153.4 (C-4), 136.3 (C-5), 152.9 (C-1′), 154.5 (C-2′), 116.0
(C-3′), 117.3 (C-4′), 120.2 (C-5′), 127.9 (C-6′), 184.3 (2 ꢀ× ꢀ COOH), 133.2
(C-2″), 116.2 (C-3″), 102.9 (C-4″), 118.1 (C-5″), 129.5 (C-1″′), 156.4 (C-2″′),
125.5 (C-3″′), 138.9 (C-4″′), 130.9 (C-4a″′), 129.5 (C-5″′), 117.2 (C-6″′),
General procedure for the preparation of the
coupling products 3–7
Dry sodium nitrite (2.07 g, 3 mmol) was slowly added over a pe-
riod of 30 min to concentrated sulfuric acid (10 mL) with occasional
stirring. The solution was cooled to 0–5°C. Compound 1a,b was
dissolved in DMSO (10 mL) and the solution cooled to 0–5°C. The
nitrosyl sulfuric acid solution was added to the solution of 1 while
the temperature was maintained at 0–5°C. The clear diazonium salt
solution 2a,b thus generated was used immediately in the coupling
reactions.
Substituted 2-aminothiophene derivative 1a–c (3 mmol) was
dissolved in DMSO (10 mL) and the solution cooled in an ice bath
to 0–5°C. The diazonium solution, generated as described above,
was added dropwise over 1 h, and then the mixture was treated with
15 mL of sodium acetate solution (10%). The resultant precipitate was
collected and crystallized from methanol.
ν
129.9 (C-7″′), 122.9 (C-8″′), 137.6 (C-8a″′); IR:
1716 (Cꢀ= ꢀO), 1532, 1440
(Nꢀ= ꢀN) cm-1; MS: m/z (%) 219 (6), 288 (35), 296 (100), 316 (9), 372 (25),
385 (36), 393 (65), 394 (5), 490 (4). Anal. Calcd for C26H19N3O10S3: C,
49.60; H, 3.04; N, 6.67; S, 15.28. Found: C, 49.57; H, 3.02; N, 6.65; S,
15.26. Rf: 0.77.
2-[2-(3-Acetyl-4-hydroxyphenyl)diazenyl]-4-(2-hydroxyphenyl)-
3-thiophene carboxylic acid (6)ꢀReaction of 1b with the diazoni-
um solution 2b gave compound 6 (560 mg, 41%) as yellow powder;
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mp 187°C (dec); H NMR: δ 7.43 (s, 2H, 5-H and 3″-H), 7.43 (d, 1H, J ꢀ= ꢀ
7.0 Hz, 3′-H), 7.79 (dd, 1H, J ꢀ= ꢀ 7.0 and 8.5 Hz, 4′-H), 7.45 (dd, 2H, J ꢀ= ꢀ
8.0 and 8.5 Hz, 5′-H and 8″-H), 7.90 (d, 1H, J ꢀ= ꢀ 8.0 Hz, 6′-H), 7.41 (d,
1H, J ꢀ= ꢀ 8.5 Hz, 6″-H), 7.76 (dd, 1H, J ꢀ= ꢀ 8.0 and 8.5 Hz, 7″-H), 8.65 (d,
1H, J ꢀ= ꢀ 8.0 Hz, 9″-H); 13C NMR: δ (see Table 1); UV-vis: λmax 241, 251,
3-[2-(4-Oxo-4H-benzo[f]thieno[3,4-c]chromen-3-yl)diazenyl]-
4H-benzo[f]thieno[3,4-c]chromen-4-one sulfate monohydrate
(3)ꢀReaction of 1a with the diazonium reagent 2a gave compound 3
(440 mg, 45%) as red powder; mp 194°C (dec); 1H NMR: δ 7.60 (s, 2H,
1-H), 7.61 (d, 2H, J ꢀ= ꢀ 9.0 Hz, 6-H), 8.38 (d, 2H, J ꢀ= ꢀ 9.0 Hz, 7-H), 8.14
(d, 2H, J ꢀ= ꢀ 7.5 Hz, 8-H), 7.69 (dd, 1H, J ꢀ= ꢀ 7.0 and 7.5 Hz, 9-H), 7.81 (dd,
2H, J ꢀ= ꢀ 7.0 and 8.0 Hz, 10-H), 8.65 (d, 2H, J ꢀ= ꢀ 9.0 Hz, 11-H); 13C NMR: δ
(see Table 1); UV-vis: λmax 242, 256, 291, 335, 345, 359, 374, 389 nm; IR:
263.5, 299, 313, 327.5, 384.5 nm; IR:
3540, 3288 (OH), 1724 (Cꢀ= ꢀO),
ν
1678, 1447 (Nꢀ= ꢀN) cm-1; MS: m/z (%) 194 (6), 225 (12), 247 (100), 307
(33), 310 (12), 382 (9), 390 (20), 406 (1). Anal. Calcd for C22H12N2O5S2:
C, 58.92; H, 2.70; N, 6.25; S, 14.30. Found: C, 58.90; H, 2.68; N, 6.26; S,
14.31. Rf: 0.53.
3300, 3400 (ꢀ= ꢀNH), 1717 (Cꢀ= ꢀO), 1615, 1597, 1440 (Nꢀ= ꢀN) cm-1; MS: m/z
ν
(%) 276 (13), 288 (33), 296 (100), 373 (60), 393 (53), 490 (10), 545 (1),
618 (1), 646 (1). Anal. Calcd for C30H18N2O9S3: C, 55.72; H, 2.81; N, 4.33;
S, 14.88. Found: C, 55.71; H, 2.79; N, 4.34; S, 14.89. Rf: 0.58.
3-Amino-1-[2-(4-oxo-4H-thieno[3,4-c]chromen-3-yl)diazenyl]-
7,11b-dihydro-4H-benzo[f]thieno[3,4-c]chromen-4-one (7)ꢀRe-
action of 1a with the diazonium solution 2b gave compound 7
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(670 mg, 45%) as green powder; mp 230°C (dec); H NMR: δ 7. 5 0
3-[2-(3-amino-4-oxo-4H-thieno[3,4-c]chromen-1-yl)diazenyl]-
4H-benzo[f]thieno[3,4-c]chromen-4-one disulfate (4)ꢀReaction
of 1c with the diazonium solution 2a gave compound 4 (420 mg,
(d, 1H, J ꢀ= ꢀ 8.0 Hz, 6-H), 8.13 (d, 1H, J ꢀ= ꢀ 8.0 Hz, 7-H), 8.70 (d, 1H,
J ꢀ= ꢀ 8.0 Hz, 8-H), 8.31 (dd, 1H, J ꢀ= ꢀ 6.0 and 8.0 Hz, 9-H), 7.22 (dd, 1H,
J ꢀ= ꢀ 6.0 and 7.5 Hz, 10-H), 8.75 (d, 1H, J ꢀ= ꢀ 7.5 Hz, 11-H), 7.68 (D2O-ex-
changeable, NH2), 7.60 (s, 1H, 1′-H), 7.72 (d, 1H, J ꢀ= ꢀ 9.2 Hz, 6′-H), 7.83
(ddd, 1H, J ꢀ= ꢀ 1.5, 8.0 and 10.0 Hz, 7′-H), 7.75 (ddd, 1H, J ꢀ= ꢀ 1.5, 9.2 and
10.0 Hz, 8′-H), 7.40 (d, 1H, J ꢀ= ꢀ 10.0 Hz, 9′-H); 13C NMR: δ 133.4 (C-1),
157.8 (C-3), 115.2 (C-3a), 164.8 (C-4), 155.6 (C-5a), 126.4 (C-6), 139.9 (C-
7), 133.2 (C-7a), 129.6 (C-8), 119.4 (C-9), 127.7 (C-10), 124.9 (C-11), 130.8
(C-11a), 130.7 (C-11b), 103.7 (C-11c), 117.4 (C-1′), 135.4 (C-3′), 154.2 (C-
3a′), 163.6 (C-4′), 152.7 (C-5a′), 118.1 (C-6′), 128.2 (C-7′), 124.9 (C-8′),
127.2 (C-9′), 130.8 (C-9a′), 155.4 (C-9b′); UV-vis: λmax 242.5, 255, 277.5,
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30%) as green powder; mp 191°C (dec); H NMR: δ 7.50 (s, 1H, 1-H),
7.62 (d, 1H, J ꢀ= ꢀ 9.0 Hz, 6-H), 8.38 (d, 1H, J ꢀ= ꢀ 9.0 Hz, 7-H), 7.80 (d, 1H, J ꢀ= ꢀ
7.0 Hz, 8-H), 7.70 (dd, 1H, J ꢀ= ꢀ 6.0 and 7.0 Hz, 9-H), 7.55 (dd, 1H, J ꢀ= ꢀ 6.0
and 7.0 Hz, 10-H), 8.65 (d, 1H, J ꢀ= ꢀ 8.0 Hz, 11-H), 7.54 (d, 1H, J ꢀ= ꢀ 7.0 Hz,
6′-H), 7.86 (dd, 1H, J ꢀ= ꢀ 7.0 and 7.0 Hz, 7′-H), 8.72 (dd, 1H, J ꢀ= ꢀ 8.0 and
8.0 Hz, 8′-H), 8.13 (d, 1H, J ꢀ= ꢀ 8.0 Hz, 9′-H), 8.08 (D2O-exchangeable,
NH2); 13C NMR: δ 120.1 (C-1), 135.5 (C-3 and C-1′), 104.9 (C-3a), 101.5 (C-
3a′), 164.5 (C-4 and C-4′), 154.8 (C-5a), 154.9 (C-5a′), 125.6 (C-6 and
C-6′), 126.3 (C-7), 131.1 (C-7a and C-11b), 129.9 (C-8), 117.1 (C-11), 129.1
(C-9), 125.4 (C-10 and C-8′), 137.6 (C-11a), 113.3 (C-11c), 156.6 (C-3′), 117.2
(C-7′), 128.9 (C-9′), 114.8 (C-9a′), 147.8 (C-9b′); UV-vis: λmax 242, 248,
ν
290, 297, 335.5, 344.5, 360, 374.5, 390 nm; IR:
1720 (Cꢀ= ꢀO), 1617,
1439 (Nꢀ= ꢀN) cm-1; MS: m/z 211 (12), 219 (34), 236 (27), 268 (100), 288
(25), 296 (54), 312 (12), 338 (32), 360 (12), 392 (11), 447 (1). Anal. Calcd
for C26H13N3O4S2: C, 63.02; H, 2.64; N, 8.48; S, 12.94. Found: C, 63.00;
H, 2.62; N, 8.46; S, 12.95. Rf: 0.56.
ν
256.5, 278, 293.5, 334, 346, 361.5, 373.5, 389.5 nm; IR:
3639, 3542,
3494, 3271 (ꢀ= ꢀNH, NH2), 3109, 3002 (Ar, C-H), 2794, 1730 (Cꢀ= ꢀO), 1703,