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M. Abbasi et al.
Letter
Synlett
(18) Sinha, S.; Ilankumaran, P.; Chandrasekaran, S. Tetrahedron 1999,
55, 14769.
(19) Prabhu, K. R.; Ramesha, A. R.; Chandrasekaran, S. J. Org. Chem.
1995, 60, 7142.
Bis(2-chlorobenzyl) disulfide (8): yellow crystals; mp70–72 °C
[Lit.27 mp 74 °C]. 1H NMR (400 MHz, CDCl3): δ = 7.19–730 (m, 2
H), 7.11–7.19 (m, 6 H), 3.70 (s, 4 H). 13C NMR (100 MHz, CDCl3):
δ = 133.9, 133.1, 130.5, 128.8, 127.9, 125.7, 40.0. Anal. Calcd for
(20) Devan, N.; Sridhar, P. R.; Prabhu, K. R.; Chandrasekaran, S. J. Org.
Chem. 2002, 67, 9417.
(21) Sureshkumar, D.; Gunasundari, T.; Ganesh, V.; Chandrasekaran,
S. J. Org. Chem. 2006, 72, 2106.
(22) Distler, H. Angew. Chem. Int. Ed. 1967, 6, 544.
(23) (a) Wang, L.; Li, P.; Zhou, L. Tetrahedron Lett. 2002, 43, 8141.
(b) Wang, L.; Zhang, Y. Tetrahedron 1999, 55, 10695. (c) Li, P.;
Wang, L.; Yang, Y.; Sun, X.; Wang, M.; Yan, J. Heteroat. Chem.
2004, 15, 376. (d) Liu, Y.; Zheng, H.; Xu, D.; Xu, Z.; Zhang, Y.
Synlett 2006, 2492.
C14H12Cl2S2: C, 53.34; H, 3.84; S, 20.34. Found: C, 53.21; H, 3.77;
S, 20.42.
n-Decyl Disulfide (13): colorless oil. 1H NMR (250 MHz, CDCl3):
δ = 2.64 (t, J = 7.3 Hz, 4 H), 1.59–1.71 (m, 4 H), 1.21–1.35 (m, 28
H), 0.82 (t, J = 6.2 Hz, 6 H). 13C NMR (62.5 MHz, CDCl3): δ = 39.2,
31.8, 29.6, 29.5, 29.3, 29.2, 29.0, 28.5, 22.8, 14.2. Anal. Calcd for
C
20H42S2: C, 69.29; H, 12.21; S, 18.50. Found: C, 69.16; H, 12.26;
S, 18.58.
Cyclopentyl Disulfide (18): colorless oil. 1H NMR (250 MHz,
CDCl3): δ = 3.39–3.45 (m, 2 H), 1.94–1.97 (m, 4 H), 1.51–1.69
(m, 12 H). 13C NMR (62.5 MHz, CDCl3): δ = 50.7, 32.9, 24.7. Anal.
Calcd for C10H18S2: C, 59.35; H, 8.97; S, 31.68. Found: C, 59.51;
H, 8.99; S, 31.50.
(24) Milligan, B.; Swan, J. M. J. Chem. Soc. 1962, 2172.
(25) General Procedure: Na2S·3H2O (0.291 g, 2.2 mmol) was added
to a magnetically stirred solution of an alkyl halide (2 mmol)
and C2Cl6 or CCl4 (1.5 mmol) in PEG-200 (2 mL) at r.t. The stir-
ring was continued until the starting halide was completely
consumed (30–150 min). Next, the reaction mixture was
diluted with H2O (1 mL) and extracted with EtOAc–hexane (1:1;
4 × 2 mL). The organic extracts were combined, concentrated
and purified by chromatography on silica gel. The desired disul-
fides were produced in excellent yields (Table 1).
Cyclohexyl Disulfide (19): colorless oil. 1H NMR (250 MHz,
CDCl3): δ = 2.64–2.73 (m, 2 H), 1.99–2.06 (m, 4 H), 1.70–1.82
(m, 4 H), 1.52–1.64 (m, 2 H), 1.17–1.31 (m, 10 H). 13C NMR (62.5
MHz, CDCl3): δ = 50.1, 32.7, 26.1, 25.7. Anal. Calcd for C12H22S2:
C, 62.55; H, 9.62; S, 27.83. Found: C, 62.40; H, 9.75; S, 27.85.
Bis(3-hydroxypropyl)disulfide (21): colorless oil. 1H NMR (400
MHz, CDCl3): δ = 3.78 (t, J = 6.0 Hz, 4 H), 3.02–3.14 (m, 4 H), 2.82
(br s, 2 H), 2.00–2.08 (m, 4 H). 13C NMR (100 MHz, CDCl3): δ =
60.9, 35.2, 31.5. Anal. Calcd for C6H14O2S2: C, 39.53; H, 7.74; S,
35.17. Found: C, 39.72; H, 7.89; S, 34.98.
Benzyl Disulfide (1): white crystals; mp 68–70 °C [Lit.13c mp
1
69–70 °C]. H NMR (400 MHz, CDCl3): δ = 7.26–7.34 (m, 10 H),
3.61 (s, 4 H). 13C NMR (100 MHz, CDCl3): δ = 138.6, 130.7, 129.7,
128.7, 44.4. Anal. Calcd for C14H14S2: C, 68.25; H, 5.73; S, 26.02.
Found: C, 68.12; H, 5.69; S, 26.19.
(26) Typical Scale-Up Procedure for the Preparation of n-Octyl
Disulfide: Na2S·3H2O (4.365g, 33 mmol) was added to a mag-
netically stirred solution of n-octyl bromide (5.182 mL, 30
mmol) and CCl4 (2.25 mL, 22.5 mmol) in PEG-200 (30 mL) at r.t.
The starting halide was completely consumed within 90 min.
Then, the mixture was diluted with H2O (15 mL) and extracted
with EtOAc–hexane (1:1; 4 × 15 mL). The upper layers were
decanted, combined, and concentrated. The crude product was
purified by silica gel chromatography using n-hexane as eluent
to provide octyl disulfide in 88% yield (3.836 g) yield.
Bis(2-methylbenzyl) Disulfide (4): white crystals; mp 71–73
°C. 1H NMR (400 MHz, CDCl3): δ = 7.13–7.21 (m, 8 H), 3.67 (s, 4
H), 2.38 (s, 6 H). 13C NMR (100 MHz, CDCl3): δ = 135.8, 134.0,
129.5, 129.4, 126.7, 124.9, 40.5, 18.2. Anal. Calcd for C16H18S2: C,
70.02; H, 6.61; S, 23.37. Found: C, 69.94; H, 6.50; S, 23.56.
Bis(3-methylbenzyl) Disulfide (5): yellow oil. 1H NMR (400
MHz, CDCl3): δ = 7.20–7.26 (m, 2 H), 7.04–7.14 (m, 6 H), 3.60 (s,
4 H), 2.36 (s, 6 H). 13C NMR (100 MHz, CDCl3): δ = 137.1, 136.2,
129.1, 127.4, 127.2, 125.4, 42.3, 20.4. Anal. Calcd for C16H18S2: C,
70.02; H, 6.61; S, 23.37. Found: C, 70.16; H, 6.52; S, 23.32.
Bis(4-methylbenzyl) Disulfide (6): colorless oil. 1H NMR (250
MHz, CDCl3): δ = 7.05–7.33 (m, 8 H), 3.71 (s, 4 H), 2.21 (s, 6 H).
13C NMR (62.5 MHz, CDCl3): δ = 137.6, 134.8, 129.8, 129.1, 43.1,
21.4. Anal. Calcd for C16H18S2: C, 70.02; H, 6.61; S, 23.37. Found:
C, 70.05; H, 6.49; S, 23.46.
n-Octyl Disulfide (12): colorless oil. 1H NMR (250 MHz, CDCl3):
δ = 2.64 (t, J = 7.3 Hz, 4 H), 1.53–1.68 (m, 4 H), 1.27–1.36 (m, 20
H), 0.81 (t, J = 6.2 Hz, 6 H); 13C NMR (62.5 MHz, CDCl3): δ = 39.2,
31.7, 29.4, 29.2, 29.1, 28.6, 22.7, 14.1. Anal. Calcd for C16H34S2: C,
66.14; H, 11.79; S, 22.07. Found: C, 65.99; H, 11.81; S, 22.20.
(27) Srivastava, S. K.; Rastogi, R.; Rajaram, P.; Butcher, R. J.; Jasinski, J.
P. Phosphorus, Sulfur, Silicon Relat. Elem. 2010, 185, 455.
© Georg Thieme Verlag Stuttgart · New York — Synlett 2015, 26, 1185–1190