PAPER
Synthesis of Diarylsulfur Diimides
657
S
S
S
S
S2Cl2
– 3/4 S8
Ar NH
S
ArNH2 + S2Cl2
Ar
N
N
Ar
Ar
N
S
N Ar
S
3
HN Ar
6
5
Scheme 5 A plausible mechanism for the formation of diarylsulfur diimides 3 from anilines
Anal. Calcd for C14H12N4O4S (332.06): C, 50.60; H, 3.64; N, 16.86;
S, 9.65. Found: C, 50.55; H, 3.41; N, 16.79; S, 9.81.
In conclusion, we have developed a direct and effective
synthesis of symmetrical diarylsulfur diimides from com-
mercial available anilines and sulfur monochloride. Di-
arylsulfur diimides are of special interest because of their
high reactivity and from a practical point of view as pre-
cursors for the preparation of the corresponding anions,
which display a rich coordination chemistry to various
metals.10 Several methods for the preparation of diarylsul-
fur diimides are known from: (1) hardly available N-sulfe-
nylamines,11 and (2) anilines and sulfur tetrafluoride,6,12
sulfur dichloride,13 or sulfur.14 However a simple, effec-
tive synthesis of diarylsulfur diimides from commercially
available reagents remains desirable.
1,3-Bis(2-methyl-3-nitrophenyl)-2λ4-diazathia-1,2-diene (3e)
Yellow crystalline solid; yield: 116 mg (70%); mp 126–128 °C.
IR (KBr): 1287 and 1100 cm–1 (N=S=N).
1H NMR (300 MHz, CDCl3): δ = 2.40 (s, 6 H, CH3), 7.08 (m, 2 H,
CH), 7.34 (d, J = 8.1 Hz, 2 H, CH), 7.53 (d, J = 8.1 Hz, 2 H, CH).
13C NMR (75.5 MHz, CDCl3): δ = 14.6 (CH3), 122.1, 125.4, and
126.3 (3 CH), 126.0, 144.9, and 151.2 (3 sp2 C).
MS (EI, 70 eV): m/z (%) = 332 (M+, 55), 317 (100), 285 (64), 181
(89), 135 (67), 90 (30), 77 (30).
Anal. Calcd for C14H12N4O4S (332.06): C, 50.60; H, 3.64; N, 16.86;
S, 9.65. Found: C, 50.32; H, 3.50; N, 16.49; S, 9.89.
1,3-Bis(4-methyl-3-nitrophenyl)-2λ4-diazathia-1,2-diene (3g)
Yellow crystalline solid; yield: 120 mg (72%); mp 112–114 °C.
IR (KBr): 1281 and 1097 cm–1 (N=S=N).
1H NMR (300 MHz, CDCl3): δ = 2.60 (s, 6 H, CH3), 7.34 (d, J = 8.1
Hz, 2 H, CH), 7.56 (d, J = 8.1 Hz, 2 H, CH), 8.03 (s, 2 H, CH).
Reagents and solvents were analytically pure grade and were used
without purification. Melting points were determined on a Kofler
hot-stage apparatus and are uncorrected. IR spectra were recorded
1
on a Specord M-80 instrument in KBr pellets. H (300 MHz) and
13C (75.5 MHz) NMR were recorded on a Bruker AM 300 in the sol-
vents indicated. Mass spectra were recorded on a Finnigan MAT
INCOS 50 instrument using electron impact ionization.
13C NMR (75.5 MHz, CDCl3): δ = 20.2 (CH3), 119.1, 127.4, and
133.3 (3 CH), 132.3, 143.5, and 149.1 (3 sp2 C).
Diarylsulfur Diimides 3; General Procedure
MS (EI, 70 eV): m/z (%) = 332 (M+, 56), 317 (100), 285 (34), 271
(33), 182 (48), 136 (33), 108 (47), 77 (50), 65 (73).
S2Cl2 (0.16 mL, 2.0 mmol) was added dropwise to a stirred soln of
the aniline (1.0 mmol) and DABCO (0.45 g, 4.0 mmol) in CHCl3
(15 mL) at –30 °C. The mixture was stirred for 1 h at r.t., refluxed
for 1 h, and cooled to 20 °C. It was then filtered and the solvent was
evaporated under reduced pressure. The residue was purified by
flash chromatography (silica gel Merck 60, hexane to hexane–
CH2Cl2 mixtures).
Anal. Calcd for C14H12N4O4S (332.06): C, 50.60; H, 3.64; N, 16.86;
S, 9.65. Found: C, 50.52; H, 3.49; N, 16.15; S, 9.92.
1,3-Bis(4-methyl-2-nitrophenyl)-2λ4-diazathia-1,2-diene (3h)
Yellow crystalline solid; yield: 139 mg (84%); mp 127–129 °C.
1,3-Bis(2-methyl-4-nitrophenyl)-2λ4-diazathia-1,2-diene (3c)
IR (KBr): 1252 and 1099 cm–1 (N=S=N).
1H NMR (300 MHz, CDCl3): δ = 2.30 (s, 6 H, CH3), 6.97 (d, J = 8.1
Hz, 2 H, CH), 7.14 (d, J = 8.1 Hz, 2 H, CH), 7.59 (s, 2 H, CH).
Orange solid; yield: 138 mg (83%); mp 132–134 °C.
IR (KBr): 1282 and 1099 cm–1 (N=S=N).
1H NMR (300 MHz, CDCl3): δ = 2.41 (s, 6 H, CH3), 7.49 (d, J = 8.8
Hz, 2 H, CH), 7.97 (d, J = 8.8 Hz, 2 H, CH), 8.11 (s, 2 H, CH).
13C NMR (75.5 MHz, CDCl3): δ = 20.7 (CH3), 123.2, 124.8, and
134.3 (3 CH), 135.8, 136.7, and 139.8 (3 sp2 C).
13C NMR (75.5 MHz, CDCl3): δ = 18.7 (CH3), 122.0, 122.0, and
MS (EI, 70 eV): m/z (%) = 332 (M+, 17), 315 (11), 286 (32), 182
(40), 152 (80), 124 (33), 76 (84), 65 (100).
125.9 (3 CH), 133.3, 145.7, and 148.5 (3 sp2 C).
MS (EI, 70 eV): m/z (%) = 332 (M+, 38), 315 (50), 285 (68), 181
(100), 152 (40), 135 (92), 122 (39), 76 (40), 64 (45).
Anal. Calcd for C14H12N4O4S (332.06): C, 50.60; H, 3.64; N, 16.86;
S, 9.65. Found: C, 50.28; H, 3.39; N, 16.67; S, 9.87.
Anal. Calcd for C14H12N4O4S (332.06): C, 50.60; H, 3.64; N, 16.86;
S, 9.65. Found: C, 50.42; H, 3.42; N, 16.54; S, 9.85.
Bis(arylamino) Disulfides 5; General Procedure
S2Cl2 (0.16 mL, 2.0 mmol) was added dropwise to a stirred soln of
the aniline (2.0 mmol) and DABCO (0.45 g, 4.0 mmol) in CHCl3
(15 mL) at –30 °C. The mixture was stirred at –20 °C for 0.5 h and
poured into H2O (20 mL). The organic layer was washed with H2O
and dried (MgSO4). Solvent was evaporated under reduced pres-
sure, and the residue was purified by flash chromatography (silica
gel Merck 60, hexane to hexane–CH2Cl2 mixtures).
1,3-Bis(2-methyl-6-nitrophenyl)-2λ4-diazathia-1,2-diene (3d)
Yellow crystalline solid; yield: 150 mg (90%); mp 159–161 °C.
IR (KBr): 1261 and 1101 cm–1 (N=S=N).
1H NMR (300 MHz, CDCl3): δ = 2.29 (s, 6 H, CH3), 6.99 (m, 2 H,
CH), 7.37 (d, J = 7.3 Hz, 2 H, CH), 7.53 (d, J = 8.1 Hz, 2 H, CH).
13C NMR (75.5 MHz, CDCl3): δ = 18.9 (CH3), 122.6, 125.1, and
N,N′-Dithiobis(2-methylaniline) (5b)
Yellow gum; yield: 251 mg (91%).
IR (KBr): 3377 cm–1 (NH).
136.1 (3 CH), 132.7, 136.7, and 139.3 (3 sp2 C).
MS (EI, 70 eV): m/z (%) = 332 (M+, 13), 286 (23), 166 (43), 164
(55), 152 (100), 150 (90), 135 (42), 106 (52), 97 (62), 91 (85), 64
(97).
© Georg Thieme Verlag Stuttgart · New York
Synthesis 2013, 45, 655–658