Vol. 26, No. 21 (2014)
Preparation of Sodium Sulfonates Using by Copper as Catalyst 7227
TABLE-1
SELECTING OF CATALYSTA
δ(ppm): 134.39, 132.48, 129.74, 129.70, 129.55, 129.20,
53.84.
Entry
Catalyst
TBAB
KBr
NaI
CuCl
Cu
Cub
Yield (%)
40.6
30.2
34.2
47.1
Sodium methyl 2-sulfoacetate: White solid, 83.4 %, 2 h.
1H NMR (600 MHz, D2O), δ (ppm): 3.97 (2H, s, CH2), 3.77
(3H, s, CH3). 13C NMR (150 MHz, D2O), δ(ppm): 167.52,
55.78, 52.26.
1
2
3
4
5
6
58.7
62.4
Sodium 2-hydroxyethanesulfonate: White solid, 77.4
%, 22 h. 1H NMR (600 MHz, D2O), δ(ppm): 3.89 (2H, s, CH2),
3.30 (OH, s), 3.10 (2H, s, CH2).13C NMR (150 MHz, D2O),
δ(ppm): 56.99, 52.86.
adichloroethane: sodium sulfite:2.5:1 (mol) reaction time:12 h solvent:
water, b solvent: the mixture of water and alcohol
make the route more competitive from an industrial point of
view with copper as the catalyst. The results are summarized
in Tables 2 and 3. It was revealed that at first the yield increased
as the reaction time prolonged. However, when the reaction
time was over 22 h, the yield increased slightly with the further
prolongation of reaction time. The yield decreased with the
reaction time prolonging to 24 h. 2-Chloro-ethanesulfonic
sodium is water-soluble and is easier to react with sodium
sulfite than dichloroethane. As a result, long reaction time
probably lead to the generation of disubstituted by-product
and the decrease of yield. Therefore the reaction time should
not exceed 22 h. It was also found that the effect of molar
ratio on the yield was similar to reaction time to some extent.
The increase of molar ratio promoted the improvement of the
yield initially.Yet when it was over 4, it did not do much great
help to the yield. Under the optimized reaction parameters as
above, the yield of the reaction increased to 80.4 % making it
more suitable for large-scale industrial production.
Sodium 1-butanesulfonate: White solid, 65.2 %, 40 h.
1H NMR (600 MHz, D2O), δ(p pm): 2.88 (2H, d, CH2), 1.68
(2H, t, CH2), 1.40 (2H, t, CH2), 0.90 (3H, d, CH3). 13CNMR
(150 MHz, D2O), δ(ppm): 50.87, 26.17, 21.16, 12.97.
Sodium 1-pentanesulfonate: White solid, 61.4 %, 40 h
(lit23). 1H NMR (600 MHz, D2O), δ(ppm): 2.86 (2H, s, CH2),
1.69 (2H, s, CH2), 1.301.36 (4H, d, CH2, CH2), 0.85 (3H, s,
CH3). 13C NMR (150 MHz, D2O), δ(ppm): 51.10, 29.97, 23.70,
21.57, 13.15.
Sodium cyclopentanesulfonate: White solid, 49.2 %, 40
h. 1H NMR (600 MHz, D2O), δ(ppm): 3.32 (1H, s, CH), 1.58-
1.96 (8H, m). 13C NMR (150 MHz, D2O), δ(ppm): 59.77,
28.3725.70.
Sodium dodecanesulphonate: White solid, 48.7 % (lit24
70 %), 40 h. 1H NMR (600 MHz, DMSO), δ(ppm): 0.86 (3H,
s, CH3), 1.24 (18H, s) 1.55 (2H, s). 13C NMR (150 MHz, D2O),
δ(ppm): 51.47, 31.26, 29.03, 28.93, 28.88, 28.68, 28.39, 25.03,
22.06, 13.92.
Sodium 2-chloro-ethanesulfonate: White solid, 81 %.
1H NMR (600 MHz, DMSO), δ(ppm): 3.82-3.84 (2H, t, J =
6Hz,CH2), 3.31-3.33 (2H, t, J = 6Hz, CH2). 13C NMR (150
MHz, D2O), δ(ppm): 52.89, 39.98.
TABLE-2
EFFECT OF REACTION TIME ON THE REACTIONA
Entry
Time (h)
16
18
Yield (%)
68.5
72.4
1
2
3
4
5
20
22
79.2
80.4
RESULTS AND DISCUSSION
24
68.8
a dichloroethane: sodium sulfite:5:1(molar ratio)
The reaction of dichloroethane and sodium sulfite is a
two-phase reaction,which inhabits efficient mixing of reaction
mixture. With considering of 1,4-dioxane possessing good
miscibility with water and organic solvents, it was employed
as the solvent for this. Unfortunately, but only low yield (35.8
%) of sodium chloroethyl sulfonate was obtained. Even in the
presence of tetrabutyl ammonium bromide, the yield of target
compound (40.6 %) was still unsatisfied. Furthermore, pota-
ssium bromide or sodium iodide was used as the catalyst.
Nevertheless, they did not lead to excellent result (30.3 % for
potassium bromide, 34.2 % for sodium iodide). According to
the reported literature20, we employed copper as the catalyst
and found that it could accelerate the reaction much better
than the catalysts above and had a good yield (58.7 %). Besides,
cuprous chloride was also employed in our reaction, however,
the result (47.1 %) was no better than copper. It was found that
copper was a catalyst with good performance for the reaction.
In view of the immiscibility of the water and organic phase,
the mixture of water and alcohol was employed as the solvent
instead of water only and it was found that the yield was further
improved (62.4 %). The results are summarized in Table-1.
If the reaction parameters was inappropriate, the reaction
might produce disubstituted by-product. Based on the research
above, the reaction time and molar ratio were optimized to
TABLE-3
EFFECT OF MOLAR RATE ON THE REACTIONA
Entry
Molar ratio
Yield (%)
63.5
74.4
81.0
80.4
1
2
3
4
2:1
3:1
4:1
5:1
a molar ratio: dichloroethane: sodium sulfite. reaction time: 22 h
Based on the good performance of copper as the catalyst
in the reaction, more chloro-hydrocarbons as raw material were
studied further. It was found that Cu has a catalytic activity
for short-chain chlorinated alkanes. Compared with the
reaction without copper as the catalyst, the yield of product
2a and 2b was improved dramatic--ally21 and the reaction time
of product 2c and 2d was shortened22. In addition, our reaction
conditions could also tolerate other functional groups such as
hydroxy, carbonyl, alkoxy and so on. However, with the incre-
asing of carbon atoms of the reactants (2e-f), the yield was
not satisfactory. It was shown evidently by secondary chloro-
hydrocarbons or high molecular weight chloro-hydrocarbons
(2g-h). The steric hindrance and the limit of long carbon chain
on the active site may be main reason that attributed to poor
reactivity of the reactants, thus leading to the low yield. Yet