JOURNAL OF SULFUR CHEMISTRY
9
filtered off and recrystallized from EtOH. During recrystallization, undissolved compound
4 was filtered off and recrystallized from CHCl /cyclohexane. The solvent of the fil-
1
3
trate was removed under vacuo and the formed precipitate 13 was recrystallized from
acetonitrile.
ꢀ
[
(
2.2 -Bi(1,3-dithiane)]-2-carbonitrile (13). Colorless crystals (0.158 g, 60%), m.p. 210°C; IR
−
1
1
λ
max, cm ) = 2940–2820 (w, Aliph-CH), 2206 (s, CN). H NMR (400.0 MHz, DMSO-
d ): δ = 3.90 (s, 1H, S–CH–S), 2.80–2.50 (m, 6H), 2.30–2.10 (m, 2H), 2.95–1.80 (m, 4H);
6
H
1
3
C NMR (100.0 MHz, DMSO-d ): δ = 114.00 (CN), 32.40 (NC-C-2), 28.00 (S–CH–S),
6
C
+
2
(
6.80, 25.60, 20.00 (2CH ). MS (70 eV, FAB): m/z = 263 (M , 37), 218 (24), 180 (17), 169
2
100), 106 (18), 48 (22). Calcd for C H NS (263.45): C, 41.03; H, 4.97; N, 5.32. Found:
9 13 4
C, 41.30; H, 4.80; N, 5.20.
ꢀ
2
,2 -Bi(1,3-dithiane) (14). Colorless crystals (0.017 g, 30%), m.p. 260–262°C; ν (λmax,
−
1
1
cm ) = 2950–2840 (w, Aliph-CH). H NMR (400.0 MHz, DMSO-d ): δ = 3.20–3.16
6
H
1
3
(
(
d, 2H, J = 6.0 Hz, CH-2), 2.85–2.80 (m, 8H, S–CH CH –S), 2.15–2.10 (m, 4H); C NMR
2
2
100.0 MHz, DMSO-d ): δ = 39.94 (2CH-2), 36.99 (4 S–CH CH –S), 23.13 (–2CH –).
6
C
2
2
2
+
MS (70 eV, FAB): m/z = 238 (M , 100), 122 (28), 108 (34). Calcd for C H S (238.44):
8
14 4
C, 40.30; H, 5.92. Found: C, 40.40; H, 5.85.
Oxidation of 10 by DDQ. A mixture of (0.238 g, 2 mmol) 14 and (2 mmol, 0.227 g) of DDQ
in 20 mL of toluene was refluxed for 8 h. The DDQ-H was filtered off and the solution was
2
evaporated in vacuo. Compound 17 was recrystallized from CHCl /cyclohexane.
3
ꢀ
ꢀ
Syn + Anti 4H,4H -2,2 -bi(1,3-dithiine) (17). Pale yellow crystals (0.187 g, 80%) of pale
−
1
yellow crystals, m.p. 280–282°C (decomp.). IR (λ , cm ) = 2920–2840 (w, Aliph-
max
1
CH), 1580–1560 (C = C). H NMR (400.0 MHz, DMSO-d ): δ = 6.20–6.16 (d, 2H,
6
H
ꢀ
J = 6.0 Hz, H-4), 6.14–6.10 (d, 2H, J = 6.0 Hz, H-4 ), 5.82–5.79 (m, 2H, H-5), 5.80–5.76
ꢀ
13
(
m, 2H, H-5 ), 4.20 (bs, 4H, CH-2), 3.30–3.00 (m, 8H); C NMR (100.0 MHz, DMSO-
ꢀ
d ): δ = 133.0, 132.60 (2CH-4,4 ), 124.80, 124.20 (2CH-4), 55.80, 55.40 (2CH-2), 27.80
6
C
+
(
4 CH -5). MS (70 eV, FAB): m/z = 234 (M , 100), 120 (34), 106 (30). Calcd for C H S
2
8
10 4
(
234.41): C, 40.99; H, 4.30. Found: C, 41.10; H, 4.20.
5.4. Reaction of 1a,b with 2-(1,3-dioxo-1H-inden-2(3H)-ylidene)malononitrile (19)
In three-necked flask, under argon, dithiol 1a,b (1 mmol) in 15 mL absolute EtOH was
added dropwise to compound 19 (0.208 g, 1 mmol) dissolved in 30 mL of absolute EtOH.
The reaction mixture was gentle refluxing for 1 h and stirred at room temperature for 24 h
to complete pre-activation. The formed precipitate 20 was filtered off and recrystallized
from MeOH.
ꢀ
2
,2 -Disulfanediyl-bis (2-(1,3-dioxo-2,3-dihydro-1H-inden-2-yl)acetonitrile (20). Pale yel-
−
1
low crystals (0.367 g, 85%), m.p. = 150–152°C. IR (λmax, cm ) = 3030–3000 (w,
1
Ar–CH), 2960–2880 (w, Aliph-CH), 2210 (CN), 1690 (s, CO). H NMR (400.0 MHz,
DMSO-d ): δH = 8.23–8.20 (m, 4H, Ar–H), 8.18–8.16 (m, 4H, Ar–H); 4.62–4.59 (d,
6
1
3
2
(
1
H, 2 –CO–CH–CO, J = 7.0 Hz), 3.60–3.57 (d, 2H, 2 S–CH–CN J = 7.0 Hz); C NMR
100.0 MHz, DMSO-d ): δ = 191.75 (4CO), 142.00, 130.18 (Ar–2C), 128.20, 127.00,
6
C
26.80, 125.60 (Ar–2CH), 115.00 (2CN), 51.95 (2 –CO–CH–CO), 19.08 (2 S–CH–CN).