720 J. CHEM. RESEARCH (S), 1999
J. Chem. Research (S),
1999, 720^721y
Efficient Synthesis of Sodium
Aryloxymethanesulfonates Using Microwave
Irradiation
A. Khala¢-Nezhad and A. Hashemi
Chemistry Department, College of Sciences, Shiraz University, Shiraz 71454, Iran
A very simple, efficient and rapid method is described for the synthesis of sodium aryloxymethanesulfonates using
microwave irradiation.
Sodium phenoxymethanesulfonate1 and its derivatives are
important intermediates in organic synthesis and are applied
Typical Procedure for the Preparation of Sodium Phenoxymethane-
sulfonate.öTo a mixture of phenol (0.012 mol, 1.12 g), sodium
chloromethanesulfonate (0.01 mol, 1.52 g) and sodium hydroxide
widely for the preparation of a-chloroanisole and its
(0.015 mol, 0.6 g) in an Erlenmeyer £ask were added four drops of
derivatives.2;3 The Barber method, which involves treatment
water at room temperature. The reaction mixture was thoroughly
of sodium chloromethanesulfonate4 with phenol in the
mixed and then placed in a microwave oven (200 W) for 35 s. After
presence of base at 200^220 8C for 4 h, is the usual method
for their synthesis.2 In recent years, the application of
microwave irradiation has rapidly increased owing to short
reactions times and operational simplicity.5 Condensation
reactions of phenols with halides, epichlorohydrine7 and
chloroacetic acid8 have recently been reported by the
microwave technique.
Here, we report that sodium phenoxymethanesulfonate
and its derivatives can be obtained from condensation of
phenols and sodium chloromethanesulfonate under
microwave irradiation in the absence of any inorganic car-
rier or organic solvent. This method is very simple and
the reaction times are very short (Scheme 1).
cooling to room temperature, 50 ml water was added and the
unreacted phenol was extracted with 20 ml diethyl ether at pH 5
(acidi¢cation via aqueous 0.5 M HCl). The aqueous solution was
boiled until the volume was reduced to 10^15 ml and then cooled.
The resulting precipitate was ¢ltered o¡ and washed subsequently
Table 1 Condensation of phenols with sodium chloromethane-
sulfonate under microwave irradiation
OH
OCH2SO3Na
NaOH, MW
+ ClCH2SO3Na
30–40 s, 85–96%
X
X
Scheme 1
The presence of a few drops of water is very important
for this reaction since in the absence of water the yield
of sodium phenoxymethanesulfonate was found to be very
low. Presumably, the major e¡ect is that water couples
e¤ciently with the microwaves and also acts as a solvent
for the reaction. The results obtained from condensation
of di¡erent phenols and sodium chloromethanesulfonate
are shown in Table 1.
A number of features of this reaction under microwave
irradiation should be noted, a substantial increase in the
yields and decrease in the reaction times are observed in
comparison with the usual thermal method at > 200 8C.
Second, the presence of substituents with different elec-
tronic and steric effects did not affect the rate and yield of
this reaction and third, the use of solvents such as DMSO
and DMF are avoided, so making the present method very
simple and environmentally safer.
Experimental
Chemicals were purchased from Fluka, Aldrich and Merck. Thin
layer chromatography (TLC) on commercial plates of silica gel 60
F254 was used to monitor the progress of the reactions. Yields refer
to isolated products after puri¢cation. Products were characterized
by comparison of their physical data (mp, IR and NMR spectra) with
samples prepared by the known method.2
* To receive any correspondence.
This is a Short Paper as de¢ned in the Instructions for Authors,
Section 5.0 [see J. Chem. Research (S), 1999, Issue 1]; there is
therefore no corresponding material in J. Chem. Research (M).
a Yields obtained using microwave method. b Yields obtained using
the Barber method.2
Khalafi-Nezhad
