The Journal of Organic Chemistry
Article
128.4, 129.8, 130.5, 132.4, 133.3, 134.1, 137.5, 148.2, 195.1. HRMS
(EI-EB): m/z [M+] calcd for C30H22O2S2, 478.1061; found, 478.1062.
1-[4-Methoxy-2-(methylthio)phenyl]-2-[2-(methylthio)phenyl]-
3-Iodo-2-[2-(methylthio)phenyl]benzo[b]thiophene (5a). White
solid, 0.245 g (64%). Mp: 113−114 °C. 1H NMR (400 MHz,
CDCl3): δ 2.42 (s, 3H), 7.24−7.34 (m, 3H), 7.40−7.47 (m, 3H), 7.80
(d, J = 8.0 Hz, 2H). 13C{1H} NMR (100 MHz, CDCl3): δ 15.9, 83.8,
122.3, 124.6, 125.3, 125.4, 125.6, 126.0, 129.9, 131.4, 133.3, 139.6,
139.7, 141.0 (one peak overlapped). HRMS (EI-EB): m/z [M+] calcd
for C15H11IS2, 381.9347; found, 381.9347.
1
ethyne (4h). Pale yellow solid, 0.784 g (87%). Mp: 58−60 °C. H
NMR (400 MHz, CDCl3): δ 2.51 (s, 3H), 2.52 (s, 3H), 3.84 (s, 3H),
6.65 (dd, J = 2.4, 8.0 Hz, 1H), 6.72 (d, J = 2.4 Hz, 1H), 7.11 (t, J =
8.0 Hz, 1H), 7.18 (d, J = 8.0 Hz, 1H), 7.28 (t, J = 8.0 Hz,1H), 7.47
(d, J = 8.0 Hz, 1H), 7.52 (d, J = 8.0 Hz, 1H). 13C{1H} NMR (100
MHz, CDCl3): δ 15.1 (two peaks overlapped), 55.3, 91.7, 93.1, 109.2,
110.5, 113.5, 121.5, 124.1, 128.5, 132.3, 133.8, 141.2, 143.3, 160.1.
HRMS (EI-EB): m/z [M+] calcd for C17H16OS2, 300.0643; found,
300.0642.
3-Iodo-6-methyl-2-[4-methyl-2-(methylthio)phenyl]benzo[b]-
1
thiophene (5b). White solid, 0.250 g (61%). Mp: 104−106 °C. H
NMR (400 MHz, CDCl3): δ 2.41 (s, 3H), 2.44 (s, 3H), 2.51 (s, 3H),
7.05 (d, J = 7.4 Hz, 1H), 7.13 (s, 1H), 7.18 (d, J = 7.4 Hz, 1H), 7.27
(d, J = 8.0 Hz, 1H), 7.59 (s, 1H), 7.66 (d, J = 8.0 Hz, 1H). 13C{1H}
NMR (100 MHz, CDCl3): δ 15.9, 21.5, 21.6, 83.4, 122.0, 125.52,
125.55, 126.2, 126.9, 130.6, 131.3, 135.6, 138.9, 139.3, 139.80, 139.85
(one peak overlapped). HRMS (EI-EB): m/z [M+] calcd for
C17H15IS2, 409.9660; found, 409.9659.
1-[5-Acetyl-2-(methylthio)phenyl]-2-[2-(methylthio)phenyl]-
1
ethyne (4i). Pale yellow solid, 0.703 g (75%). Mp: 110−111 °C. H
NMR (400 MHz, CDCl3): δ 2.54 (s, 3H), 2.56 (s, 3H), 2.60 (s, 3H),
7.14 (t, J = 7.6 Hz, 1H), 7.19−7.23 (m, 2H), 7.34 (t, J = 8.0 Hz, 1H),
7.56 (dd, J = 1.2, 7.6 Hz, 1H), 8.90 (dd, J = 2.0, 8.4 Hz, 1H), 8.09 (d,
J = 2.0 Hz, 1H). 13C{1H} NMR (100 MHz, CDCl3): δ 14.8, 15.1,
26.4, 92.0, 94.1, 120.5, 120.6, 122.8, 124.0, 124.2, 128.2, 129.2, 132.3,
132.7, 133.8, 141.8, 148.7, 196.7. HRMS (EI-EB): m/z [M+] calcd for
C18H16OS2, 312.0643; found, 312.0644.
3-Iodo-6-tert-butyl-2-[4-tert-butyl-2-(methylthio)phenyl]benzo-
[b]thioophene (5c). White solid, 0.321 g (65%). Mp: 125−127 °C.
1H NMR (400 MHz, CDCl3): δ 1.38 (s, 9H), 1.40 (s, 9H), 2.42 (s,
3H), 7.22 (d, J = 8.0 Hz, 1H), 7.26 (d, J = 8.0 Hz, 1H), 7.36 (s, 1H),
7.52 (d, J = 8.4 Hz, 1H), 7.71 (d, J = 8.4 Hz, 1H), 7.80 (s, 1H).
13C{1H} NMR (100 MHz, CDCl3): δ 16.2, 31.3, 31.5, 35.0, 35.1,
83.1, 118.3, 122.1, 123.0, 123.5, 125.3, 130.8, 131.6, 138.5, 138.7,
139.6, 140.4, 148.9, 152.8. HRMS (FAB-EB): m/z [M+ + H] calcd for
C23H28IS2, 495.0677; found, 495.0677.
3-Iodo-6-methoxy-2-[4-methoxy-2-(methylthio)phenyl]benzo-
[b]thiophene (5d). White solid, 0.296 g (67%). Mp: 114−117 °C. 1H
NMR (400 MHz, CDCl3): δ 2.41 (s, 3H), 3.89 (s, 3H), 3.90 (s, 3H),
6.76 (dd, J = 2.0, 8.4 Hz, 1H), 6.84 (s, 1H), 7.07 (dd, J = 2.0, 8.8 Hz,
1H), 7.22 (d, J = 8.4 Hz, 1H), 7.28 (s, 1H), 7.66 (d, J = 8.8 Hz, 1H).
13C{1H} NMR (100 MHz, CDCl3): δ 15.7, 55.4, 55.7, 83.4, 104.6,
1-[5-Acetyl-2-(methylthio)phenyl]-2-[4-methoxy-2-(methylthio)-
phenyl]ethyne (4j). Pale yellow solid, 1.02 g (99%). Mp: 100−101
1
°C. H NMR (400 MHz, CDCl3): δ 2.51 (s, 3H), 2.53 (s, 3H), 2.58
(s, 3H), 3.84 (s, 3H), 6.65 (dd, J = 2.4, 8.4 Hz, 1H), 6.70 (d, J = 2.4
Hz, 1H), 7.18 (d, J = 8.4 Hz, 1H), 7.48 (d, J = 8.4 Hz, 1H), 7.85 (dd,
J = 2.0, 8.4 Hz, 1H), 8.05 (d, J = 2.0 Hz, 1H). 13C{1H} NMR (100
MHz, CDCl3): δ 14.7, 15.0, 26.4, 55.3, 90.6, 94.2, 109.2, 110.4, 112.8,
120.8, 122.6, 127.8, 131.9, 132.7, 133.9, 143.5, 148.3, 160.3, 196.7.
HRMS (EI-EB): m/z [M+] calcd for C19H18O2S2, 342.0748; found,
342.0747.
1-[4-Chloro-2-(methylthio)phenyl]-2-[4-methyl-2-(methylthio)-
109.2, 111.4, 115.2, 125.4, 126.5, 132.6, 135.0, 138.0, 140.7, 141.3,
158.3, 160.6. HRMS (EI-EB): m/z [M+] calcd for C17H15IO2S2,
441.9558; found, 441.9557.
phenyl]ethyne (4k). Pale yellow solid, 0.832 g (87%). Mp: 111−113
1
°C. H NMR (400 MHz, CDCl3): δ 2.37 (s, 3H), 2.506 (s, 3H),
2.510 (s, 3H), 6.93 (d, J = 7.6 Hz, 1H), 6.99 (s, 1H), 7.07 (dd, J = 1.6,
8.0 Hz, 1H), 7.11 (d, J = 1.6 Hz, 1H), 7.41−7.44 (m, 2H). 13C{1H}
NMR (100 MHz, CDCl3): δ 15.1, 15.2, 21.7, 91.4, 94.3, 118.1, 119.7,
123.6, 124.3, 124.9, 125.3, 132.5, 133.3, 134.7, 139.4, 141.3, 143.7.
HRMS (EI-EB): m/z [M+] calcd for C17H15ClS2, 318.0304; found,
318.0304.
1-[4-Chloro-2-(methylthio)phenyl]-2-[4-tert-butyl-2-
(methylthio)phenyl]ethyne (4l). Pale yellow solid, 0.920 g (85%).
Mp: 52−54 °C. 1H NMR (400 MHz, CDCl3): δ 1.33 (s, 9H), 2.50 (s,
3H), 2.54 (s, 3H), 7.07 (d, J = 8.0 Hz, 1H), 7.11 (s, 1H), 7.15 (d, J =
8.4 Hz, 1H), 7.23 (s, 1H), 7.44 (d, J = 8.0 Hz, 1H), 7.46 (d, J = 8.4
Hz, 1H). 13C{1H} NMR (100 MHz, CDCl3): δ 14.8, 15.2, 30.9, 34.8,
91.1, 94.2, 118.3, 119.3, 121.5, 121.6, 123.2, 123.9, 132.2, 133.0,
134.4, 140.6, 143.6, 152.1. HRMS (EI-EB): m/z [M+] calcd for
C20H21ClS2, 360.0773; found, 360.0772.
6-Chloro-2-[4-chloro-2-(methylthio)phenyl]-3-iodobenzo[b]-
1
thiophene (5e). White solid, 0.334 g (74%). Mp: 170−171 °C. H
NMR (400 MHz, CDCl3): δ 2.44 (s, 3H), 7.21−7.22 (m, 2H), 7.26
(s, 1H), 7.43 (dd, J = 2.0, 8.8 Hz, 1H), 7.71 (d, J = 8.8 Hz, 1H), 7.81
(d, J = 2.0 Hz, 1H). 13C{1H} NMR (100 MHz, CDCl3): δ 15.7, 83.5,
121.8, 124.7, 124.8, 126.2, 126.9, 130.8, 132.0, 132.4, 136.3, 139.5,
140.2, 140.4, 142.1. HRMS (EI-EB): m/z [M+] calcd for C15H9Cl2IS2,
449.8567; found, 449.8568.
5-Acetyl-2-[5-acetyl-2-(methylthio)phenyl]-3-iodobenzo[b]-
1
thiophene (5f). White solid, 0.373 g (80%). Mp: 185−187 °C. H
NMR (400 MHz, CDCl3): δ 2.50 (s, 3H), 2.62 (s, 3H), 2.76 (s, 3H),
7.37 (d, J = 8.4 Hz, 1H), 7.88 (d, J = 2.0 Hz, 1H), 7.91 (d, J = 8.8 Hz,
1H), 8.03−8.07 (m, 2H), 8.38 (d, J = 1.2 Hz, 1H). 13C{1H} NMR
(100 MHz, CDCl3): δ 15.5, 27.0, 27.2, 85.5, 123.0, 124.3, 125.4,
127.2, 130.0, 131.5, 132.3, 133.6, 135.2, 141.3, 141.5, 144.6, 147.3,
196.9, 197.8. HRMS (FAB-EB): m/z [M+ + H] calcd for
C19H16IO2S2, 466.9636; found, 466.9635.
1-[4-Chloro-2-(methylthio)phenyl]-2-[4-methoxy-2-(methylthio)-
phenyl]ethyne (4m). Pale yellow solid, 0.733 g (73%). Mp: 110−112
1
°C. H NMR (400 MHz, CDCl3): δ 2.505 (s, 3H), 2.509 (s, 3H),
5-Benzoyl-2-[5-benzoyl-2-(methylthio)phenyl]-3-iodobenzo[b]-
1
3.85 (s 3H), 6.66 (dd, J = 2.0, 8.4 Hz, 1H), 6.71 (s, 1H), 7.07 (dd, J =
2.0, 8.4 Hz, 1H), 7.10 (d, J = 2.0 Hz, 1H), 7.42 (d, J = 8.0 Hz, 1H),
7.46 (d, J = 8.4 Hz, 1H). 13C{1H} NMR (100 MHz, CDCl3): δ 15.07,
15.14, 55.4, 90.7, 94.1, 109.3, 110.5, 113.2, 119.7, 123.5, 124.2, 133.1,
133.9, 134.5, 143.4, 160.3 (one peak overlapped). HRMS (EI-EB):
m/z [M+] calcd for C17H15ClOS2, 334.0253; found, 334.0253.
3-Iodobenzothiophenes 5 by Iodination of 1-Aryl-2-[2-
(methylthio)phenyl]ethynes 4. To a solution of 1-aryl-2-[2-
(methylthio)phenyl]ethyne 4 (1.0 mmol) in CH2Cl2 (1 mL) were
added PhI(OAc)2 (0.193 g, 0.6 mmol) and I2 (0.152 g, 0.6 mmol),
and the mixture was stirred at room temperature for 3 h. The reaction
mixture was quenched with aqueous Na2S2O3 and extracted with
CH2Cl2 (10 mL × 3). The organic phase was washed with water and
dried over anhydrous Na2SO4. The solvent was evaporated by a rotary
evaporation, and the residue was submitted to column chromatog-
raphy on silica gel. Elution with CH2Cl2/hexane (1:3) gave the
desired product.
thiophene (5g). White solid, 0.484 g (82%). Mp: 199−200 °C. H
NMR (400 MHz, CDCl3): δ 2.53 (s, 3H), 7.41 (d, J = 8.4 Hz, 1H),
7.47−7.65 (m, 6H), 7.74 (d, J = 2.0 Hz, 1H), 7.83−7.94 (m, 6H),
7.97 (dd, J = 2.0, 8.0 Hz, 1H), 8.22 (s, 1H). 13C{1H} NMR (100
MHz, CDCl3): δ 15.7, 85.4, 122.8, 124.3, 127.3, 128.8, 128.9, 130.3,
130.5, 132.0, 132.2, 132.8, 132.9, 133.5, 133.8, 135.5, 137.9, 138.0,
141.1, 141.6, 144.1, 146.7, 195.5, 196.5 (one peak overlapped).
HRMS (EI-EB): m/z [M+] calcd for C29H20IO2S2, 590.9949; found,
590.9947.
3-Iodo-2-[4-methoxy-2-(methylthio)phenyl]benzo[b]thiophene
1
(5h). White solid, 0.309 g (75%). Mp: 133−134 °C. H NMR (400
MHz, CDCl3): δ 2.42 (s, 3H), 3.89 (s, 3H), 6.78 (dd, J = 2.4, 8.6 Hz,
1H), 6.86 (d, J = 2.4 Hz, 1H), 7.22 (d, J = 8.6 Hz, 1H), 7.38−7.48
(m, 2H), 7.79 (d, J = 8.4 Hz, 2H). 13C{1H} NMR (100 MHz,
CDCl3): δ 15.7, 55.4, 84.3, 109.3, 111.4, 122.2, 125.2, 125.3, 125.5,
125.9, 132.4, 139.7, 140.88, 140.90, 141.1, 160.7. HRMS (EI-EB): m/
z [M+] calcd for C16H13IOS2, 411.9452; found, 411.9452.
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J. Org. Chem. XXXX, XXX, XXX−XXX