S. P. G. Costa, R. M. F. Batista, P. Cardoso, M. Belsley, M. M. M. Raposo
FULL PAPER
1
(
1
1
1 H, 3, 4-H and 9×Ar-H), 9.90 (s, 1 H, CHO) ppm. 13C NMR
CDCl ): δ = 124.03, 126.78, 126.93, 127.76, 127.83, 128.91, 131.89,
37.48, 139.93, 142.19, 142.35, 153.89, 182.75 ppm. IR (nujol): ν˜ =
3Ј- and 5Ј-H), 7.92 (dd, J = 7.2, 1.2 Hz, 1 H, 7-H), 8.09 (dd, J =
7.2, 1.2 Hz, 1 H, 4-H), 8.11 (d, J = 8.8 Hz, 2 H, 2Ј- and 6Ј-H) ppm.
C NMR (CDCl ): δ = 121.61 (C-7), 123.15 (C-4), 124.02 (C-3ЈЈ),
3
125.20 (C-6), 125.85 (C-5ЈЈ), 126.17 (C-3Ј and -5Ј), 126.37 (C-5),
128.06 (C-2Ј and -6Ј), 128.28 (C-4ЈЈ), 132.40 (C-1Ј), 134.97 (C-7a),
3
1
3
658 cm–1 (s) cm . MS (EI): m/z (%) = 264 [M , 67], 207 (100).
–1
+
EI-HRMS: calcd. for C17
H12OS 264.0609, found 264.0598.
1
36.81 (C-4Ј), 143.26 (C-2ЈЈ), 154.15 (C-3a), 167.43 (C-2) ppm. IR
2
-Formyl-5-(4Ј-phenoxyphenyl)thiophene (5h): Yellow solid (87 mg,
(
KBr): ν˜ = 1602, 1479, 1425, 1315, 1250, 1115, 965, 816, 757,
1
3
26%). M.p. 82.6–83.7 °C. H NMR (CDCl ): δ = 7.02–7.10 (m, 4
–
1
692 cm . C17
2
H11NS (293.41): calcd. C 69.59, H 3.78, N 4.77, S
H, 4×Ar-H), 7.13–7.20 (br. t, J = 7.5 Hz, 1 H, Ar-H), 7.33 (d, J
4.2 Hz, 1 H, 4-H), 7.35 (br. t, J = 7.5 Hz, 2 H, 2×Ar-H), 7.64
d, J = 8.7 Hz, 2 H, 2×Ar-H), 7.73 (d, J = 4.2 Hz, 1 H, 3-H), 9.88
s, 1 H, CHO) ppm. 13C NMR (CDCl
): δ = 118.81, 119.53, 123.54,
24.07, 127.84, 127.96, 129.94, 137.62, 141.96, 153.87, 156.18,
21.85; found C 69.53, H 3.91, N 4.84, S 21.54.
=
(
(
2-[5Ј-(4ЈЈ-Methoxyphenyl)thien-2Ј-yl]-1,3-benzothiazole (6b): Yellow
solid (333 mg, 86%). M.p. 154.3–155.7 °C. H NMR (CDCl
3.86 (s, 3 H, OCH ), 6.96 (d, J = 8.7 Hz, 2 H, 3ЈЈ- and 5ЈЈ-H), 7.22
(d, J = 3.3 Hz, 1 H, 4Ј-H), 7.37 (dt, J = 7.8, 1.2 Hz, 1 H, 6-H),
7.48 (dt, J = 7.8, 1.2 Hz, 1 H, 5-H), 7.61 (m, 3 H, 3Ј-, 2ЈЈ- and 6ЈЈ-
H), 7.84 (dd, J = 7.8, 1.2 Hz, 1 H, 7-H), 8.02 (dd, J = 7.8, 1.2 Hz,
1
3
3
): δ =
1
1
3
–1
58.76, 182.74 ppm. IR (nujol): ν˜ = 1653 (s) cm . C17
H
12
O
2
S
(280.35): calcd. C 72.84, H 4.28, S 11.45; found C 72.86, H 4.33, S
11.40.
1
3
1
3
6
3
1
1
3 3
H, 4-H) ppm. C NMR (CDCl ): δ = 55.37 (OCH ), 114.47 (C-
2-Formyl-5-(1Ј-naphthyl)thiophene (5i): Yellow oil (254 mg, 89%).
ЈЈ and -5ЈЈ), 121.38 (C-7), 122.77 (C-4), 122.79 (C-4Ј), 125.04 (C-
), 126.31 (C-1ЈЈ), 126.39 (C-5), 127.26 (C-2ЈЈ and -6ЈЈ), 129.59 (C-
Ј), 134.57 (C-7a), 135.01 (C-2Ј), 148.28 (C-5Ј), 153.71 (C-3a),
59.93 (C-4ЈЈ), 161.36 (C-2) ppm. IR (KBr): ν˜ = 1604, 1544, 1481,
[
11]
1
[ref. 72–73 °C (EtOH and benzene)]. H NMR (CDCl
3
): δ = 7.36
(d, J = 3.9 Hz, 1 H, 4-H), 7.50–7.64 (m, 4 H, 4×Ar-H), 7.85 (d, J
=
1
3.9 Hz, 1 H, 3-H), 7.90–8.00 (m, 2 H, 2×Ar-H), 8.14–8.20 (m,
H, Ar-H), 9.97 (s, 1 H, CHO) ppm. 13C NMR (CDCl
): δ =
3
–
1
443, 1431, 1250, 1178, 1023, 904, 830, 794, 735, 724 cm . MS
1
1
25.01, 125.16, 126.34, 126.99, 128.27, 128.52, 128.58, 129.72,
30.99, 131.04, 133.73, 136.62, 143.44, 152.24, 182.91 ppm. IR (nu-
+
(
C
EI): m/z (%) = 323 (100) [M ], 308 (55). EI HRMS: calcd. for
13NOS 323.0439, found 323.0437.
H
2
–
1
+
18
jol): ν˜ = 1666 (s) cm . MS (EI): m/z (%) = 238 (100) [M ]. EI
HRMS: calcd. for C15 10OS 238.0452, found 238.0444.
H
2-[5Ј-(2ЈЈ,4ЈЈ-Dimethoxyphenyl)thien-2Ј-yl]-1,3-benzothiazole (6c):
1
Yellow solid (127 mg, 30%). M.p. 108.0–111.0 °C. H NMR ([D
DMSO): δ = 3.83 (s, 3 H, OCH ), 3.98 (s, 3 H, OCH ), 6.66 (dd,
J = 8.4, 2.1 Hz, 1 H, 5ЈЈ-H), 6.74 (d, J = 2.1 Hz, 1 H, 3ЈЈ-H), 7.42
dt, J = 8.1, 0.9 Hz, 1 H, 6-H), 7.51 (dt, J = 8.1, 0.9 Hz, 1 H, 5-
6
]-
5
1
-(4Ј-Fluorophenyl)-2-formylthiophene (5j): Yellow solid (47 mg,
9%). M.p. 113.2–114.0 °C (ref.[ no value quoted). 1H NMR
): δ = 7.14 (t, JH–F = 8.4 Hz, 2 H, 3Ј- and 5Ј-H), 7.35 (d, J
3.9 Hz, 1 H, 4-H), 7.63–7.68 (m, 2 H, 2Ј- and 6Ј-H), 7.75 (d, J
12]
3
3
(CDCl
3
(
=
=
H), 7.62 (d, J = 3.9 Hz, 1 H, 4Ј-H), 7.78 (d, J = 3.9 Hz, 1 H, 3Ј-
H), 7.81 (d, J = 8.4 Hz, 1 H, 6ЈЈ-H), 7.97 (dd, J = 8.1, 0.9 Hz, 1
H, 4-H), 8.08 (dd, J = 8.1, 0.9 Hz, 1 H, 7-H) ppm. C NMR
13
3
3.9 Hz, 1 H, 3-H), 9.90 (s, 1 H, CHO) ppm. C NMR (CDCl ):
δ = 116.29 (d, JC–F = 22.1 Hz, C-3Ј and -5Ј), 124.06 (C-4), 128.27
d, JC–F = 8.4 Hz, C-2Ј and -6Ј), 129.40 (d, JC–F = 3.9 Hz, C-1Ј),
37.41 (C-3), 142.51 (C-2), 153.03 (C-5), 163.38 (d, JC–F = 250 Hz,
1
3
(
1
(CDCl
3 3 3
): δ = 55.49 (OCH ), 55.60 (OCH ), 98.88 (C-5ЈЈ), 105.38
(
C-3ЈЈ), 115.66 (C-1ЈЈ), 121.33 (C-7), 122.69 (C-4), 124.57 (C-4Ј),
–1
C-4Ј), 182.73 (CHO) ppm. IR (KBr): ν˜ = 1641 (s) cm . MS (EI):
m/z (%) = 206 [M , 85], 205 (100). EI HRMS: calcd. for C11H FOS
7
1
7
24.84 (C-6), 126.27 (C-5), 128.59 (C-3Ј), 128.99 (C-6ЈЈ), 134.55 (C-
a), 135.07 (C-2Ј), 143.95 (C-5Ј), 153.87 (C-3a), 157.05 (C-4ЈЈ or
+
206.0202, found 206.0209.
-
2ЈЈ), 160.95 (C-4ЈЈ or -2ЈЈ), 161.96 (C-2) ppm. IR (KBr): ν˜ = 2961,
2
8
4
8
9
-Formyl-5-(4Ј-formylphenyl)thiophene (5k): Yellow solid (220 mg, 2928, 2849, 1605, 1515, 1470, 1447, 1313, 1246, 1021, 835,
1
–1
+
5%). M.p. 145.3–146.1 °C. H NMR (CDCl
3
): δ = 7.54 (d, J =
740 cm . MS (EI): m/z (%) = 353 (100) [M ], 338 (42). EI HRMS:
.2 Hz, 1 H, 4-H), 7.79 (d, J = 4.2 Hz, 1 H, 3-H), 7.84 (d, J = calcd. for C H NO S 353.0544, found 353.0530.
1
9
15
2 2
.4 Hz, 2 H, 2Ј- and 6Ј-H), 7.96 (d, J = 8.4 Hz, 2 H, 3Ј- and 5Ј-H),
.93 (s, 1 H, CHO), 10.05 (s, 1 H, CHO) ppm. 13C NMR (CDCl
):
2
-[5Ј-(4ЈЈ-Ethoxyphenyl)thien-2Ј-yl]-1,3-benzothiazole (6d): Yellow
3
1
solid (335 mg, 83%). M.p. 147.5–148.9 °C. H NMR (CDCl
.45 (t, J = 6.9 Hz, 3 H, CH ), 4.85 (q, J = 6.9 Hz, 2 H, CH
d, J = 8.7 Hz, 2 H, 3ЈЈ- and 5ЈЈ-H), 7.04 (d, J = 3.6 Hz, 1 H, 4Ј-
H), 7.36 (dt, J = 7.5, 1.2 Hz, 1 H, 6-H), 7.48 (dt, J = 7.5, 1.2 Hz,
3
): δ =
δ = 125.70, 126.78, 130.48, 136.41, 137.13, 138.49, 143.86, 151.78,
1
(
3
2
), 6.95
–
1
182.76, 191.20 ppm. IR (nujol): ν˜ = 1696 (s), 1654 (s) cm . MS
+
(EI): m/z (%) = 216 (98) [M ], 215 (100). EI HRMS: calcd. for
12 8 2
C H O
S 216.0245, found 216.0242.
1
H, 5-H), 7.60 (m, 3 H, 3Ј-, 2ЈЈ- and 6ЈЈ-H), 7.85 (dd, J = 7.5,
1
3
General Procedure for the Syntheses of Benzothiazoles 6: The corre-
sponding formyl derivatives 5 and o-aminobenzenethiol (1.1 equiv.)
1.2 Hz, 1 H, 7-H), 8.04 (dd, J = 7.5, 1.2 Hz, 1 H, 4-H) ppm.
C
NMR (CDCl ): δ = 14.76 (CH ), 63.58 (CH ), 114.98 (C-3ЈЈ and
3
3
2
were heated in DMSO (0.5 mL/mmol) at 120 °C with stirring for -5ЈЈ), 121.38 (C-7), 122.71 (C-4Ј), 122.76 (C-4), 125.03 (C-5), 126.13
3
0–60 min. The reaction was monitored by TLC using chloroform/
(C-1ЈЈ), 126.38 (C-6), 127.24 (C-2ЈЈ and -6ЈЈ), 129.59 (C-3Ј), 134.56
(C-7a), 134.93 (C-2Ј), 148.38 (C-5Ј), 153.72 (C-3a), 159.32 (C-4ЈЈ),
161.38 (C-2) ppm. IR (KBr): ν˜ = 3000, 2990, 1596, 1546, 1483,
hexane (1:1) as eluent. When the reaction was complete, the reac-
tion mixture was cooled and poured into water and extracted with
ethyl acetate (3×30 mL). The organic layer was dried with magne- 1446, 1390, 1251, 1184, 1117, 1081, 1047, 901, 830, 789, 754,
–
1
+
sium sulfate and the solvents were evaporated under vacuum. The
crude residue was chromatographed using silica gel and mixtures
of hexane and chloroform of increasing polarity. The fractions con-
taining the purified product were collected and the solvents evapo-
rated under vacuum.
731 cm . MS (EI): m/z (%) = 337 (100) [M ], 309 (72), 308 (79).
EI HRMS: calcd. for C H NOS 337.0595, found 337.0607.
1
9
15
2
2
-[5Ј-(4ЈЈ-Hydroxyphenyl)thien-2Ј-yl]-1,3-benzothiazole (6e): Light
1
brown solid (148 mg, 40%). M.p. 212.4–213.5 °C. H NMR
CDCl ): δ = 6.82 (d, J = 9.0 Hz, 2 H, 3ЈЈ- and 5ЈЈ-H), 7.11 (d, J
= 3.9 Hz, 1 H, 4Ј-H), 7.27 (dt, J = 7.8, 1.2 Hz, 1 H, 6-H), 7.38 (dt,
3
299 mg, 85%). M.p. 205.5–206.1 °C. H NMR (CDCl ): δ = 7.14– J = 7.8, 1.2 Hz, 1 H, 5-H), 7.42 (d, J = 9.0 Hz, 2 H, 2ЈЈ- and 6ЈЈ-
(
3
2
-[4Ј-(Thien-2ЈЈ-yl)phenyl]-1,3-benzothiazole (6a): Yellow solid
1
(
7
.20 (m, 1 H, 4ЈЈ-H), 7.36 (dd, J = 5.1, 1.2 Hz, 1 H, 5ЈЈ-H), 7.40
H), 7.50 (d, J = 3.9 Hz, 1 H, 3Ј-H), 7.76 (dd, J = 7.8, 1.2 Hz, 1 H,
7-H), 7.90 (dd, J = 7.8, 1.2 Hz, 1 H, 4-H), 9.03 (br. s, 1 H, OH)
(dt, J = 7.2, 1.2 Hz, 1 H, 6-H), 7.44 (dd, J = 3.6, 1.2 Hz, 1 H, 3ЈЈ-
1
3
H), 7.51 (dt, J = 7.2, 1.2 Hz, 1 H, 5-H), 7.74 (d, J = 8.8 Hz, 2 H,
ppm. C NMR (CDCl
3
): δ = 115.94 (C-3ЈЈ and -5ЈЈ), 121.18 (C-
3944
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© 2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim Eur. J. Org. Chem. 2006, 3938–3946