434
Russ.Chem.Bull., Int.Ed., Vol. 50, No. 3, March, 2001
Kutchin et al.
heating rate of 6 grad min1. Authentic samples of sulfides,
sulfoxides, and sulfones were used as reference standards. IR
spectra were recorded on a Specord M 80 instrument for CCl4
solutions with a layer thickness of 0.2 mm or for KBr pellets in
the region of 4004000 cm1. NMR spectra were recorded on
Tesla BS-467-A (60 ÌHz) and Tesla BS-567 (100 ÌHz)
spectrometers in CCl4 or CDCl3 using HMDS as the internal
standard. Elemental analysis was carried out using an EA 1110
CHNS-O automated analyzer. Melting points were determined
in an open capillary.
added with stirring at 20 °C over a period of 60 min to a
solution of Pr2S (0.84 g, 7 mmol) in 5 mL of AcOEt. Then the
reaction mixture was extracted with chloroform. The solvent
was evaporated to give 0.92 g (97%) of an oxidized product
containing, according to GLC, 95% sulfoxide and 2% sulfone.
The major product was distilled in vacuo, b.p. 81 °C (2 Torr)
(cf. Ref. 27). Found (%): C, 53.69; H, 10.56; S, 23.97.
C6H14OS. Calculated (%): C, 53.69; H, 10.51; S, 23.88. IR,
1
ν/cm
(CCl4): 1050 (S=O). 1H NMR (CDCl3), δ: 1.10 (t,
6 H, 2 CH3, J = 7.0 Hz); 1.85 (m, 4 H, 2 CH2); 2.68 (m, 4 H,
The dipropyl, diisobutyl, and dioctyl sulfides used in the
work were commercial preparations. The solvents were purified
by distillation.
The authentic sulfoxides and sulfones were prepared by
known procedures.18,19
2 CH2S).
Oxidation by gaseous ClO2 (method 2). A mixture of air
with chlorine dioxide (prepared from 100 mL of an aqueous
solution containing 4 g L
solution of di(n-octyl) sulfide (4.25 g, 16 mmol) in CH2Cl2
(25 mL). The reaction mixture was stirred for 2 h at 20 °C. The
solvent was evaporated to give after silica gel chromatography
(eluent benzeneEtOH (4 : 1)) 4.0 g (89%) of sulfoxide as
white crystals, m.p. 69 °C (cf. Ref. 21: m.p. 70 °C). Found (%):
C, 70.24; H, 12.35; S, 11.82. C16H34OS. Calculated (%):
1
of ClO2) was bubbled through a
Preparation of sulfoxides (general procedure).18 An equimo-
lar amount of a 30% solution of H2O2 was added dropwise with
stirring at 20 °C to a sulfide (0.05 mol) in 30 mL of Ac2O. The
reaction time was 2024 h. Acetic anhydride was evaporated in
vacuo from the reaction mixture and the remaining sulfoxide
was either distilled or recrystallized from EtOH.
Preparation of sulfones (general procedure).19 A sulfide
(0.01 mol) in 30 mL of glacial AcOH was placed in a flask
equipped with a stirrer and dropping funnel. Then an excess
(0.0250.03 mol) of a 30% solution of H2O2 was added with
stirring and ice cooling. The reaction mixture was stirred on a
water bath for 2 h at 5060 °C, poured onto crushed ice, and
extracted with ether. The ethereal extract was washed with a
saturated solution of NaHCO3 and water and dried with Na2SO4.
After evaporation of the solvent, the sulfone was recrystallized
from a mixture of hexane with ether (2 : 1).
1
C, 70.01; H, 12.48; S, 11.68. IR, ν/cm (CCl4): 1050 (S=O).
1H NMR (CDCl3), δ: 0.85 (t, 6 H, 2 CH3, J = 7.0 Hz); 1.24
(m, 16 H, 8 CH2); 1.41 (m, 4 H, 2 CH2); 1.73 (m, 4 H,
2 CH2); 2.61 (m, 4 H, 2 CH2S).
Oxidation of ClO2 dissolved in an organic solvent (method 3).
Ethyl acetate (25 mL) containing 3 g L1 (1.15 mmol) of ClO2
(prepared from 18 mL of an aqueous solution containing
1
4.2 g L
of ClO2) was added with stirring to a solution of
di(p-tolyl) sulfide (0.50 g, 2.3 mmol) in AcOEt (5 mL). The
reaction mixture was stirred for 3 h at 20 °C (to complete
decoloration). The solvent was evaporated to give after silica gel
chromatography (eluent benzeneEtOH (4 : 1)) 0.52 g
(94%) of di(p-tolyl) sulfoxide, m.p. 89 °C (cf. Ref. 22: m.p.
92 °C). Found (%): C, 73.18; H, 6.30; S, 13.82. C14H14OS.
Calculated (%): C, 73.01; H, 6.13; S, 13.92.
The following compounds were prepared in a similar way
(the yields and purity characteristics are listed in Table 3).
Diisobutyl sulfoxide. Found (%): C, 59.41; H, 11.27;
S, 19.89. C8H18OS. Calculated (%): C, 59.21; H, 11.18; S, 19.75.
Characteristics of the authentic samples of sulfones are
presented below.
Di(n-propyl) sulfone, m.p. 30 °C (cf. Ref. 20: m.p.
1
2930 °C). IR, ν/cm
(O=S=O).
(KBr): 11201160, 12701320
Di(n-octyl) sulfone, m.p. 76 °C (cf. Ref. 21: m.p. 7677 °C).
1
IR, ν/cm (KBr): 11201160, 12701320 (O=S=O).
Di(p-tolyl) sulfone, m.p. 7980 °C (cf. Ref. 22: m.p. 80 °C).
1
1
IR, ν/cm (KBr): 11201160, 12701320 (O=S=O).
IR, ν/cm (CCl4): 1050 (S=O).
Di(isobutyl) sulfone, m.p. 18 °C (cf. Ref. 23: m.p. 17 °C).
Butyl methyl sulfoxide. Found C, 50.22; H, 10.31; S, 26.45.
Found (%): C, 53.88; H, 10.02; S, 17.82. C8H18O2S. Calcu-
C5H12OS. Calculated (%): C, 49.96; H, 10.06; S, 26.67. IR,
1
1
lated (%): C, 53.93; H, 10.11; S, 17.92. IR, ν/cm
11201160, 12701320 (O=S=O).
(CCl4):
ν/cm (CCl4): 1050 (S=O).
Dibenzyl sulfoxide. Found (%): C, 73.12; H, 6.31; S, 13.73.
Butyl methyl sulfone. Found (%): C, 44.01; H, 8.93; S, 23.67.
C14H14OS. Calculated (%): C, 73.01; H, 6.13; S, 13.91. IR,
ν/cm (CCl4): 1050 (S=O).
1
C5H12O2S. Calculated (%): C, 44.12; H, 8.82; S, 23.53. IR,
1
ν/cm (CCl4): 11201160, 12701320 (O=S=O).
p,p´-Dibromodiphenyl sulfoxide, m.p. 148 °C (cf. Ref. 28:
m.p. 152 °C). Found (%): C, 40.25; H, 2.08; S, 8.94.
C12H8Br2OS. Calculated (%): C, 40.03; H, 2.24; S, 8.91. IR,
Dibenzyl sulfone, m.p. 149 °C (cf. Ref. 24: m.p. 150 °C). IR,
1
ν/cm (KBr): 11201160, 12701320 (O=S=O).
1
p,p´-Dibromodiphenyl sulfone, m.p. 167 °C (cf. Ref. 25:
ν/cm (CCl4): 1050 (S=O).
1
m.p. 168 °C). IR, ν/cm
(O=S=O).
(KBr): 11201160, 12701320
The authors are grateful to Yu. G. Yatluk for provid-
ing di(p-tolyl) sulfide, and p,p´-dibromodiphenyl sulfide
samples and to N. K. Lyapina for methyl butyl sulfide
and dibenzyl sulfide samples.
This work was financially supported by the Federal
Science and Engineering Program "Methodology of Tar-
geted Organic Synthesis."
Oxidation of sulfides was carried out using chlorine dioxide
1
as an aqueous solution with a concentration of 45 g L
prepared by an industrial technology at the Syktyvkar LPK
joint-stock company. The oxidation by gaseous ClO2 implies
the use of a ClO2air mixture. This mixture was prepared by
bubbling air through an aqueous solution of chlorine dioxide;
the amount of chlorine dioxide was calculated from the initial
ClO2 concentration in the aqueous solution. A solution of ClO2
in AcOEt was prepared by carrying chlorine dioxide with a slow
flow of air from an aqueous solution into AcOEt cooled to 0 °C.
The concentration of chlorine dioxide was determined in all
cases by a known procedure.26
References
1. A. V. Kuchin and L. L. Frolova, Izv. Akad. Nauk, Ser.
Khim., 2000, 1658 [Russ. Chem. Bull., Int. Ed., 2000,
49, 1647].
Oxidation by an aqueous solution of ClO2 (method 1). An
aqueous solution (5 g L1) of ClO2 (48 mL, 3.5 mmol) was