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5.3.4. 4-{[2,6-Dinitro-4-(trifluoromethyl)phenyl]sulfanyl}phenyl
methyl ether (7)
5.3.8. 2-[(2,4-Dichloro-5-methylphenyl)sulfanyl]-1,5-dinitro-3-
(trifluoromethyl)benzene (16)
4-Methoxybenzenethiol 2e (505 mg, 3.6 mmol) was coupled to
4-chloro-3,5-dinitrobenzotrifluoride 3b (812 mg, 3.0 mmol) using
triethylamine (607 mg, 6 mmol), neocuproine (125 mg, 0.6 mmol),
and copper(I) iodide (114 mg, 0.6 mmol) in ethyl acetate (20 ml).
The product was purified by reverse-phase C18-silica gel column
chromatography (eluent 50–90% acetone in water), giving
458 mg of a yellow solid, 41% yield, mp 125–127 °C. 1H NMR (ace-
tone-d6) o 3.83 (3H, s), 6.91–6.96 (2H, m, AA’ of an AA’XX’ system),
7.37–7.43 (2H, m, XX’ of an AA’XX’ system), 8.54 (2H, d, J = 0.6 Hz).
2,4-Dichloro-5-methylthiophenol 2a (267 mg, 1.4 mmol) was
coupled to 2-chloro-3,5-dinitrobenzotrifluoride 3c (322 mg, 1.2
mmol) using triethylamine (283 mg, 2.8 mmol), neocuproine
(58 mg, 0.3 mmol), and copper(I) iodide (53 mg, 0.3 mmol) in ethyl
acetate (20 ml). The product was purified by silica gel column
chromatography (eluent 0–20% dichloromethane and hexanes)
and reverse-phase C18-silica gel column chromatography (eluent
25–75% acetone and water), giving 300 mg of a yellow solid, 59%
yield, mp 126–130 °C. 1H NMR (acetone-d6) o 2.24 (3H, s), 7.13
(1H, s), 7.59 (1H, s), 8.91 (1H, d, J = 2.6 Hz), 9.06 (1H, d,
J = 2.6 Hz). 13C NMR (acetone-d6) o 18.45, 122.01 (q, J = 274.5 Hz),
123.61, 125.13 (q, J = 5.9 Hz), 129.74, 130.43 (d, J = 1.1 Hz),
131.02, 131.92, 132.80, 134.53, 135.67 (q, J = 32.5 Hz), 136.51,
148.37, 154.99. HRMS [M+Na]+ calcd 448.9353, obsd 448.9356.
Anal. (C14H7Cl2F3N2O4S) calcd C 39.36%, H 1.65%, N 6.56%; obsd C
39.63%, H 1.69%, N 6.48%.
13C NMR (acetone-d6) o 54.97, 115.21, 120.68, 122.21 (q, JCF
=
272.3 Hz), 125.27 (q, JCF = 3.8 Hz), 129.54 (q, JCF = 35.5 Hz),
133.36, 135.25, 152.40, 161.09. HRMS [M+H]+ calcd 375.0262, obsd
375.0269. Anal. (C14H9F3N2O5S) calcd C 44.92%, H 2.42%, N 7.48%;
obsd C 44.97%, H 2.40%, N 7.44%.
5.3.5. 2-Cyclohexylsulfanyl-1,3-dinitro-5-(trifluoromethyl)-
benzene (10)
Cyclohexylmercaptan 2h (116 mg, 1.0 mmol) was coupled to
4-chloro-3,5-dinitrobenzotrifluoride 3b (271 mg, 1.0 mmol) using
KOtBu (224 mg, 2.0 mmol), ethylene glycol (125 mg, 2.0 mmol, Mal-
linckrodt), and copper(I) iodide (38 mg, 0.2 mmol) in isopropanol
(10 ml). The product was purified by silica gel column chromatogra-
phy (eluent 100% hexanes), giving an orange–yellow solid, 11% yield,
mp 60–64 °C. 1H NMR (acetone-d6) o 1.16–1.43 (6H, m), 1.59 (1H,
m), 1.78 (4H, m) and 8.58 (2H, d, J = 0.6 Hz). 13C NMR o (acetone-
d6) 24.96, 25.54, 33.23, 49.83, 122.10 (q, JCF = 272.8), 123.50 (q,
JCF = 3.8), 125.57, 132.14 (q, JCF = 35.8 Hz), 155.61. HRMS [M+Na]+
calcd 373.0446, obsd 373.0448. Anal. (C13H13F3N2O4S) calcd C
44.57%, H 3.74%, N 8.00%; obsd C 45.01%, H 3.81%, N 7.98%.
5.3.9. 2-[(2,4-Dichloro-5-methylphenyl)sulfanyl]-1,3-dinitro-5-
methylbenzene (17)
2,4-Dichloro-5-methylthiophenol 2a (368 mg, 1.9 mmol) was
coupled to 2-chloro-1,3-dinitro-5-methylbenzene 3d (367 mg,
1.7 mmol) using triethylamine (405 mg, 4 mmol), neocuproine
(83 mg, 0.4 mmol), and copper(I) iodide (76 mg, 0.4 mmol) in ethyl
acetate (20 ml). The product was purified by silica gel column
chromatography (eluent 0–25% dichloromethane in hexanes),
recrystallization from hexanes, reverse-phase C18-silica gel column
chromatography (eluent 25–100% acetone/water), and a second
recrystallization from hexanes, giving 178 mg of a yellow solid,
28% yield, mp 177–178 °C. 1H NMR (acetone-d6) o 2.27 (3H, m),
2.63 (3H, t, J = 0.7 Hz), 7.23 (1H, m, J = 0.8 Hz), 7.52 (1H, m,
J = 0.3 Hz), 8.12 (2H, d, J = 0.7 Hz). 13C NMR (acetone-d6) o 18.50,
20.00, 117.52, 128.50, 129.70, 130.56, 131.87, 133.83, 134.44,
136.10, 143.64, 153.59. HRMS [M+Na]+ calcd 394.9636, obsd
394.9639. Anal. (C14H10Cl2N2O4S) calcd C 45.05%, H 2.70%, N
7.51%; obsd C 45.11%, H 2.67%, N 7.42%.
5.3.6. 2-Ethylsulfanyl-1,3-dinitro-5-(trifluoromethyl)benzene (11)
In this coupling method, the ligand was neocuproine at 0.2 mol
equiv, the base was KOtBu at 2 mol equiv and the solvent was
tetrahydrofuran (THF). Ethanethiol 2i (839 mg, 11 mmol) was
coupled to 4-chloro-3,5-dinitrobenzotrifluoride 3b (271 mg, 1.0
mmol) using KOtBu (224 mg, 2.0 mmol), neocuproine (42 mg,
0.2 mmol), and copper(I) iodide (38.1 mg, 0.2 mmol) in anhydrous
THF (10 ml). The product was purified by silica gel column chroma-
tography (eluent 100% hexanes), giving 59 mg of a yellow solid,
20% yield, mp 88–90 °C (lit. 89–90 °C).43 1H NMR (acetone-d6) o
1.24 (3H, t, J = 7.4 Hz), 3.03 (2H, q, J = 7.4 Hz) and 8.61 (2H, d,
5.3.10. 4-[(2,4-Dichloro-5-methylphenyl)sulfanyl]-3,5-dinitro-
benzonitrile (18)
2,4-Dichloro-5-methylthiophenol 2a (194 mg, 1 mmol) was
coupled to 4-chloro-3,5-benzonitrile 3e (191 mg, 0.84 mmol) using
triethylamine (203 mg, 2 mmol), neocuproine (42 mg, 0.2 mmol),
and copper(I) iodide (38 mg, 0.2 mmol) in ethyl acetate (10 ml).
The product was purified by silica gel column chromatography
(eluent 0–50% chloroform in hexanes) and recrystallization from
hexanes, giving 133 mg of a yellow solid, 41% yield, mp 195 °C.
1H NMR (acetone-d6) o 2.31 (3H, s), 7.56 (1H, d, J = 0.6 Hz), 7.59
(1H, s), and 8.78 (2H, s). 13C NMR (acetone-d6) o 18.38, 113.06,
114.82, 127.81, 130.14, 130.56, 132.08, 133.98, 136.25, 136.35,
136.64, (the signal for the nitro-containing carbons on ring B, ex-
pected between 150 and 160 ppm, is too small to be distinguished
from noise). HRMS [M+Na]+ 405.9432, obsd 405.9435. Anal.
(C14H7Cl2N3O4S) calcd C 43.77%, H 1.84%, N 10.94%; obsd C
43.54%, H 1.82%, N 10.76%.
J = 0.6 Hz). 13C NMR (acetone-d6) o 13.84, 30.87, 122.15 (q, JCF
=
272.5 Hz), 123.91 (q, JCF = 3.8 Hz), 127.74, 131.57 (q, JCF = 35.5 Hz),
155.06. HRMS [M+Na]+ calcd 318.9976, obsd 318.9967. Anal.
(C9H7F3N2O4S) calcd C 36.49%, H 2.38%, N 9.46%; obsd C 36.94%,
H 2.43%, N 9.39%.
5.3.7. 2-[(2,4-Dichloro-5-methylphenyl)sulfanyl]-1,3-dinitro-
benzene (12)
2,4-Dichloro-5-methylthiophenol 2a (368 mg, 2 mmol) was cou-
pled to 2-chloro-1,3-dinitrobenzene 3a (344 mg, 1.7 mmol) using
triethylamine (405 mg, 4 mmol), neocuproine (83 mg, 0.4 mmol),
and copper(I) iodide (76 mg, 0.4 mmol) in ethyl acetate (20 ml).
The product was purified by silica gel column chromatography (elu-
ent 0–30% dichloromethane in hexanes), recrystallization from hex-
anes, reverse-phase C18-silica gel column chromatography (eluent
0–50% acetone in water), and recrystallization from dichlorometh-
ane, giving 213 mg of a yellow solid, 35% yield, mp 181–184 °C. 1H
NMR (acetone-d6) o 2.29 (3H, t, J = 0.4 Hz), 7.33 (1H, d, J = 0.4 Hz),
7.53 (1H, s), 7.98 (1H, dd, J = 8.1 Hz) and 8.29 (2H, d, J = 8.1 Hz).
13C NMR (acetone-d6) o 18.46, 122.21, 128.37, 129.79, 129.83,
131.18, 132.61, 134.72, 134.98, 136.24, 153.34. HRMS [M+Na]+
calcd 380.9480, obsd 380.9469. Anal. (C13H8Cl2N2O4S) calcd C
43.47%, H 2.24%, N 7.80%; obsd C 43.57%, H 2.16%, N 7.76%.
5.3.11. 2-[(2,4-Dichloro-5-methylphenyl)sulfanyl]-1,3,5-tris(tri-
fluoromethyl)benzene (19)
2,4-Dichloro-5-methylthiophenol 2a (368 mg, 1.9 mmol) was
coupled to 2,4,6-tris(trifluoromethyl)chlorobenzene 3f (538 mg,
1.7 mmol) using triethylamine (405 mg, 4 mmol), neocuproine
(83 mg, 0.4 mmol), and copper(I) iodide (76 mg, 0.4 mmol) in ethyl
acetate (20 ml). The product was purified by silica gel column chro-
matography (eluent 100% hexanes), recrystallization from hexanes
and reverse-phase C18-silica gel column chromatography twice
(eluent 0–75% then 50–90% acetone/water), giving 90 mg of a white