# Supplementary Material (ESI) for Green Chemistry
# This journal is © The Royal Society of Chemistry 2007
A Highly Advantageous Metal-Free Approach to Diaryl Disulfides in Water
Mónica Carril, Raul SanMartin, Esther Domínguez and Imanol Tellitu
Electronic Supplementary Information
General Remarks. All the thiophenols were purchased from Aldrich and used
without further purification. The ammonia aqueous solution (32%) was purchased from
Scharlau. Redistilled water was employed in all reactions. TLC was carried out on SiO2
(silica gel 60 F254, Merck), and the spots were located with UV light. Drying of organic
extracts after work-up of reactions was performed over anhydrous Na2SO4. 1H and
13
C
spectra were recorded in CDCl3 solution in a Bruker AC-300 and chemical shifts are
reported in ppm downfield (δ) from Me4Si. Low and high resolution mass spectra were
performed by the Mass Spectroscopy Section of the University of the Basque Country
(UPV/EHU).
Experimental procedure for the synthesis of disulfides 2.
S
S
Diphenyl disulfide 2a.1 Typical procedure: A schlenck flask was charged with thiophenol
(0.1 ml, 0.94 mmol), a 32% aqueous solution of NH3 (0.15 ml) and water (6ml). The
schlenk was sealed and the mixture was stirred at room temperature for 2 hours. The crude
mixture was filtered to afford disulfide 2a (99.7 mg, 97%) as a white solid. δH(300 MHz,
CDCl3, Me4Si) 7.22-7.35 (6H, m, Harom), 7.53 (4H, d, J 7.43, Harom); δC(75 MHz, CDCl3,
1
R. Leino, J. –E. Loennqvist, Tetrahedron Lett. 2004, 45, 8489.
S1
Me4Si) 126.9, 127.3, 128.9, 136.8; m/z (EI) (Found: 218.0228. C12H10S2 requires:
218.0224) 218 (M, 100), 185 (14), 154 (14), 109 (95).
S
S
Di(2-naphthyl) disulfide 2b.2 The typical procedure was followed employing 2thionaphthol (161.9 mg, 1 mmol). The reaction was performed at 120°C for 4 hours and the
crude mixture was filtered to afford disulfide 2b (134.5 mg, 85%) as a beige solid. δH(300
MHz, CDCl3, Me4Si) 7.49-7.45 (4H, m, Harom), 7.65 (2H, d, J 8.66, Harom), 7.82-7.73 (6H,
m, Harom), 8.01 (2H, s, Harom); δC(75 MHz, CDCl3, Me4Si) 125.6, 126.2, 126.5, 126.7,
127.4, 127.7, 128.9, 132.4, 133.4, 134.2; m/z (EI) (Found: 318.0544. C20H14S2 requires:
318.0537) 318 (M, 12), 254 (16), 159 (40), 115 (100).
OMe
S
S
MeO
Di(4-methoxyphenyl) disulfide 2c.3 The typical procedure was followed employing 4methoxythiophenol (0.13 ml, 1.04 mmol). The reaction was performed at 120°C for 4 hours
and the crude mixture was extracted with dichloromethane to afford disulfide 2c (139.7 mg,
97%) as a colourless liquid. δH(300 MHz, CDCl3, Me4Si) 3,80 (6H, s, OCH3), 6.84 (4H, d,
J 8.79, Harom), 7.40 (4H, d, J 8.79, Harom); δC(75 MHz, CDCl3, Me4Si) 55,3, 114,6, 128,4,
132,6, 159,9; m/z (EI) (Found: 278.0438. C14H14O2S2 requires: 278.0435) 278 (M, 66), 139
(100), 96 (14).
Cl
S
S
Cl
Di(4-chlorophenyl) disulfide 2d.4 The typical procedure was followed employing 4chlorothiophenol (151.9 mg, 1.05 mmol). The reaction was performed at 120°C for 4 hours
and the crude mixture was filtered to afford disulfide 2d (149.0 mg, 99%) as a white solid.
2
A. Khazaei, M. A. Zolfigol, A. Rostami, Synthesis 2004, 2959.
G. Palumbo, R. Caputo, Synthesis 1981, 888.
4
X. Huang, C. C. Chan, Synthesis 1982, 1091.
3
S2
δH(300 MHz, CDCl3, Me4Si) 7.28 (4H, d, J 8.55, Harom), 7.41 (4H, d, J 8.55, Harom); δC(75
MHz, CDCl3, Me4Si) 129.2, 133.5, 135.1; m/z (EI) (Found: 285.9452. C12H8S2Cl2 requires:
285.9444 ) 290 (M +4, 3), 288 (M+2, 20), 286 (M, 32), 143 (100), 108 (66), 99 (13).
NO2
S
S
O2N
Di(4-nitrophenyl) disulfide 2e.5 The typical procedure was followed employing 4nitrothiophenol (196.0 mg, 1.01 mmol). The reaction was performed at room temperature
for 4 hours and the crude mixture was filtered to afford disulfide 2e (133.7 mg, 86%) as a
yellow solid. δH(300 MHz, CDCl3, Me4Si) 7.61 (4H, d, J 8.92, Harom), 8.19 (4H, d, J 8.89,
Harom); δC(75 MHz, CDCl3, Me4Si) 124.4, 126.3, 144.0, 146.9; m/z (EI) (Found: 307.9930.
C12H8N2O4S2 requires: 307.9926) 308 (M, 100), 278 (11), 140 (11), 138 (18), 108 (61).
Me
S
S
Me
Di(4-methylphenyl) disulfide 2f.6 The typical procedure was followed employing 4methylthiophenol (156.4 mg, 1.23 mmol). The reaction was performed at 120°C for 4 hours
and the crude mixture was filtered to afford disulfide 2f (144.9 mg, 95%) as a yellow solid.
δH(300 MHz, CDCl3, Me4Si) 2.38 (6H, s, CH3), 7.16 (4H, d, J 7.92, Harom), 7.46 (4H, d, J
8.07, Harom); δC(75 MHz, CDCl3, Me4Si) 20.9, 128.4, 129.7, 133.8, 137.3; m/z (EI) (Found:
246.0541. C14H14S2 requires: 246.0537) 246 (M, 87), 123 (100), 79 (15).
MeO
S
S
OMe
Di(3-methoxyphenyl) disulfide 2g.7 The typical procedure was followed employing 3methoxythiophenol (0.13 ml, 1.03 mmol). The reaction was performed at 120°C for 4 hours
and the crude mixture was extracted with dichloromethane to afford disulfide 2g (133 mg,
F. –E. Chen, Y. –W. Lu, Y. –P. He, Y. –F. Luo, M. –G. Yan, Synth Commun. 2002, 32, 3487.
R. S. Sengar, V. N. Nemykin, P. Basu, New J. Chem. 2003, 27, 1115.
7
C. N. Yiannios, J. V. Karabinos, J. Org. Chem. 1963, 28, 3246.
5
6
S3
93%) as a yellow oil. δH(300 MHz, CDCl3, Me4Si) 3.78 (6H, s, OCH3), 6.79 (2H, d, J 7.46,
Harom), 7.11-7.14 (4H, m, Harom), 7.24 (2H, t, J 8.17, Harom); δC(75 MHz, CDCl3, Me4Si)
55.1, 112.4, 112.9, 119.4, 129.8, 138.1, 159.9; m/z (EI) (Found: 278.0422. C14H14O2S2
requires: 278.0435) 278 (M, 100), 245 (22), 230 (189, 214 (18), 139 (21), 124 (18), 95 (20).
Me
S
S
Me
Di(3-methylphenyl) disulfide 2h.8 The typical procedure was followed employing 3methylthiophenol (0.13 ml, 1.04 mmol). The reaction was performed at 120°C for 4 hours
and the crude mixture was was extracted with dichloromethane to afford disulfide 2h (127
mg, 99.5%) as a yellow liquid. δH(300 MHz, CDCl3, Me4Si) 2.38 (3H, s), 7.08 (2H, d, J
7.47, Harom), 7.25 (2H, t, J 7.92, Harom), 7.36-7.40 (4H, m, Harom); δC(75 MHz, CDCl3,
Me4Si) 21.3, 124.4, 127.8, 127.9, 128.8, 136.8, 138.8; m/z (EI) (Found: 246.0545. C14H14S2
requires: 246.0537) 246 (M, 100), 213 (16), 198 (10), 182 (19), 123 (90), 79 (15).
Me
Me
S
S
Me
Me
Bis(2,6-dimethylphenyl) disulfide 2i.9 The typical procedure was followed employing 2,6dimethylthiophenol (0.14 ml, 1.00 mmol). The reaction was performed at 120°C for 4 hours
and the crude mixture was filtered to afford disulfide 2i (134.5 mg, 98%) as a yellow solid.
δH(300 MHz, CDCl3, Me4Si) 2.28 (12H, s, CH3), 7.03-7.06 (4H, m, Harom), 7.14 (2H, dd, J
8.22, 6.63, Harom); δC(75 MHz, CDCl3, Me4Si) 21.4, 127.9, 129.2, 134.6, 143.3; m/z (EI)
(Found: 246.0545. C14H14S2 requires: 246.0537) 246 (M, 100), 213 (16), 198 (10), 182
(19), 123 (90), 79 (15).
NH2
S
S
NH2
8
9
W. E. Fristad, J. R. Peterson, Synth. Commun. 1985, 15, 1.
H. Fujihara, J. J. Chiu, N. Furukawa, Bull. Chem. Soc. Jpn. 1991, 64, 699.
S4
Di(2-aminophenyl) disulfide 2j.10 The typical procedure was followed employing 2aminothiophenol (0.11 ml, 1.02 mmol). The reaction was performed at room temperature
for 2 hours and the crude mixture was filtered to afford disulfide 2j (95.8 mg, 76%) as a
yellow solid. δH(300 MHz, CDCl3, Me4Si) 4.33 (4H, s, NH2), 6.59 (2H, t, J 7.48, Harom),
6.66-6.74 (2H, m, Harom), 7.13-7.19 (4H, m, Harom); δC(75 MHz, CDCl3, Me4Si) 115.2,
118.2, 131.6, 136.8, 148.6; m/z (EI) (Found: 248.0444. C12H12N2S2 requires: 248.0442) 248
(M, 19), 124 (100), 97 (11), 80 (52).
N
S
S
N
Di(2-pyridinyl) disulfide 2k.1 The typical procedure was followed employing 2mercaptopyridine (122.2 mg, 1.09 mmol). The reaction was performed at room temperature
for 2 hours and the crude mixture was filtered to afford disulfide 2k (99.3 mg, 83%) as a
yellow solid. δH(300 MHz, CDCl3, Me4Si) 6.73 (2H, t, J 6.49, Harom), 7.31-7.37 (2H, m,
Harom), 7.47-7.57 (4H, m, Harom); δC(75 MHz, CDCl3, Me4Si) 113.9, 133.6, 136.7, 137.8,
176.4; m/z (EI) (Found: 220.0120. C10H8N2S2 requires: 220.0129) 220 (M, 100), 156 (68),
83 (12), 78 (60).
N
S
S
N
Di(4-pyridinyl) disulfide 2l.11 The typical procedure was followed employing 4mercaptopyridine (120.1 mg, 1.03 mmol). The reaction was performed at 120°C for 7 hours
and the crude mixture was extracted with dichloromethane to afford disulfide 2l (99.6 mg,
88%) as an orange oil. δH(300 MHz, CDCl3, Me4Si) 7.17 (4H, d, J 6.05, Harom), 8.46 (4H, d,
J 6.01, Harom); δC(75 MHz, CDCl3, Me4Si) 124.6, 143.8, 150.1.
10
11
G. Crank, M. I. H. Makin, Tetrahedron Lett. 1979, 23, 2169.
F. Jordan, Z. Kudzin, Z. Witczak, P. Hoops, J. Org. Chem. 1986, 51, 571.
S5
S
S
2a
8.0
7.0
6.0
5.0
4.0
ppm (t1)
126,962
127,337
128,867
136,847
100
50
ppm (t1)
S6
3.0
ppm (t1)
125,597
126,195
126,476
126,698
127,420
127,725
128,940
132,439
133,417
134,210
50
100
150
ppm (t1)
S7
3.0
4.0
5.0
6.0
7.0
8.0
S
S
2b
OMe
S
S
MeO
2c
8.0
7.0
6.0
5.0
4.0
ppm (t1)
55,327
114,586
128,403
132,620
159,885
150
100
50
ppm (t1)
S8
3.0
Cl
S
S
Cl
2d
8.0
7.0
6.0
5.0
4.0
ppm (t1)
129,235
133,546
135,064
150
ppm (t1)
100
50
S9
3.0
NO2
S
S
O2N
2e
ppm (t1)
9.0
7.0
6.0
5.0
4.0
124,430
126,315
144,027
146,908
150
8.0
100
50
ppm (t1)
S10
3.0
Me
S
S
Me
2f
8.0
7.0
6.0
5.0
4.0
3.0
2.0
ppm (t1)
20,989
128,411
129,715
133,806
137,312
150
ppm (t1)
100
50
S11
MeO
S
S
OMe
2g
8.0
7.0
6.0
5.0
4.0
ppm (t1)
55,151
112,439
112,970
119,425
129,814
138,146
159,936
150
100
50
ppm (t1)
S12
3.0
Me
S
S
Me
2h
8.0
7.0
6.0
5.0
4.0
3.0
2.0
ppm (t1)
21,309
124,444
127,892
127,925
128,831
136,826
138,822
150
ppm (t1)
100
50
S13
Me
Me
S
S
Me
Me
2i
8.0
7.0
6.0
5.0
4.0
3.0
2.0
ppm (t1)
21,368
127,954
129,178
134,630
143,307
150
ppm (t1)
100
50
S14
NH2
S
S
NH2
2j
8.0
7.0
6.0
5.0
4.0
ppm (t1)
150
100
50
ppm (t1)
S15
3.0
N
S
S
N
2k
8.0
ppm (t1)
7.0
6.0
5.0
S16
4.0
3.0
N
S
S
N
2l
9.0
8.0
7.0
6.0
5.0
ppm (t1)
124,629
143,824
150,121
150
100
50
ppm (t1)
S17
4.0