Novelties of solid-liquid phase transfer catalysed synthesis of p-toluenesulfonyl fluoride from p-toluenesulfonyl chloride

Article abstract of DOI:10.1016/j.jfluchem.2004.10.013

Organic sulfonyl fluorides are of interest owing to their insecticidal, germicidal and enzyme inhibitory properties. In the current work synthesis of p-toluenesufonyl fluoride was accomplished by reacting p-toluenesulfonyl chloride with solid potassium fluoride using PEG-400 as a catalyst under solid-liquid phase transfer catalysis (S-L PTC) at 30°C. p-Toulenesulfonyl fluoride is used as peroxygen bleach activator. It also finds use in the treatment of Alzheimer's disease. The mechanism is based on homogeneous solubilization of solid. PEG forms a complex with metal cation which associates with the nucleophile and it participates in S_N2 type reaction. The reaction is intrinsically kinetically controlled. A complete theoretical analysis is done to determine both the rate constant and equilibrium constant from the same set of data. The activation energy and Gibbs free energy are also calculated.

Full text of DOI:10.1016/j.jfluchem.2004.10.013

Journal of Fluorine Chemistry 126 (2005) 99–106
www.elsevier.com/locate/fluor
Novelties of solid–liquid phase transfer catalysed synthesis of
p-toluenesulfonyl fluoride from p-toluenesulfonyl chloride
*
Ganapati D. Yadav , Priyanvada M. Paranjape
Department of Chemical Engineering, University Institute of Chemical Technology,
University of Mumbai, Matunga, Mumbai 400019, India
Received 2 October 2004; accepted 26 October 2004
Available online 10 December 2004
Abstract
Organic sulfonyl fluorides are of interest owing to their insecticidal, germicidal and enzyme inhibitory properties. In the current work
synthesis of p-toluenesufonyl fluoride was accomplished by reacting p-toluenesulfonyl chloride with solid potassium fluoride using PEG-400
as a catalyst under solid–liquid phase transfer catalysis (S–L PTC) at 30 8C. p-Toulenesulfonyl fluoride is used as peroxygen bleach activator.
It also finds use in the treatment of Alzheimer’s disease. The mechanism is based on homogeneous solubilization of solid. PEG forms a
complex with metal cation which associates with the nucleophile and it participates in S 2 type reaction. The reaction is intrinsically
N
kinetically controlled. A complete theoretical analysis is done to determine both the rate constant and equilibrium constant from the same set
of data. The activation energy and Gibbs free energy are also calculated.
#
2004 Published by Elsevier B.V.
Keywords: Solid–liquid phase transfer catalysis; p-Toluenesulfonyl fluoride; KF; PEG-400; Rate constant; Equilibrium constant; Modeling
1
. Introduction
dimethylformamide (62–72%) [1]. All of these methods give
low yield of the compound. On the other hand if hydrogen
fluoride is used as fluorinating agent, it has been reported
that with sulfonyl chlorides, the reaction had to be carried
out under pressure and at elevated temperature for a longer
period. Due to high reaction temperatures required,
substantial amounts of energy must be employed when
the processes are carried out on an industrial scale.
Organic sulfonyl fluorides are of interest owing to their
insecticidal, germicidal and enzyme inhibitory properties. p-
Toluenesulfonyl fluoride is used as peroxygen bleach
activator. It also finds use in the treatment of Alzheimer’s
disease. There are several routes for manufacture of organic
sulfonyl fluorides, most of which involve halogen exchange
(
i.e., conversion of the corresponding sulfonyl chloride to
We would like to report a very facile and convenient
method (which generates a naked fluoride anion) to
synthesize p-toluenesulfonyl fluoride at room temperature.
Further a general modeling method is devised by which it
would be possible to determine the rate constant and also the
overall equilibrium constant using the same set of data.
Phase transfer catalysis (PTC) has matured to over 600
industrial processes in a variety of industries such as
intermediates, dyestuffs, agrochemicals, perfumes, flavours,
pharmaceuticals and polymers [2–4]. A large number of
PTC processes use the liquid–liquid (L–L) mode of
operation. One of the ways to suppress by-product formation
and also intensify the rates of reactions of L–L PTC is
through the use of solid–liquid phase transfer catalysis (S–L
the sulfonyl fluoride). Boiling of a sulfonyl chloride with an
aqueous solution of potassium fluoride will not work for
water sensitive compounds. Other synthesis include: (a)
refluxing the corresponding sulfonyl chloride and potassium
fluoride in a cosolvent system (e.g., dioxane/water) (70%
yield), (b) addition of sodium nitrite to a solution of the
corresponding sulfonamide in anhydrous hydrogen fluoride
(53–78%), (c) heating the sulfonyl chloride with sodium
fluoride suspended in tetramethylenesulfone, acetonitrile or
*
Corresponding author. Tel.: +91 22 2410 2121; fax: +91 22 2414 5614.
E-mail addresses: gdyadav@yahoo.com, gdyadav@udct.org
(G.D. Yadav).
0022-1139/$ – see front matter # 2004 Published by Elsevier B.V.
doi:10.1016/j.jfluchem.2004.10.013

100
G.D. Yadav, P.M. Paranjape / Journal of Fluorine Chemistry 126 (2005) 99–106
PTC). The aqueous phase promoted reactions can thus be
totally suppressed and better selectivities obtained. While
L–L PTC involves heterogeneous reaction between two
reagents located in an aqueous, and an organic phase, S–L
PTC involves reaction of an anionic reagent in a solid phase
(
usually a salt) with a reactant located in a continuous
organic phase. Yadav and Sharma [5] proposed the first
mechanistic and kinetic model of solid–liquid PTC followed
by Naik and Doraiswamy [6]. We have carried out the
detailed mechanistic and modeling studies for industrially
important reactions under S–L PTC conditions [7,8]. The
role of small amounts of water, the so-called omega phase, in
S–L PTC was analysed in our earlier work [9] including
others [2–4] and a rigorous model of S–L PTC with omega
phase has been established [9].
+
Scheme 1. Complex of PEG with metal cation K .
ꢀ
the solid and the transport of another nucleophile [F ] into
the organic phase. In the current case, the S–L PTC
mechanistic description is the implication that the reaction
takes place in anhydrous condition, since both solid and
liquid phases were dry. So the formation of the omega phase
was discounted. There are two types of mechanisms for S–L
PTC, the homogeneous solubilization mechanism of Yadav
and Sharma [5] and heterogeneous solubilization of Naik
and Doraiswamy [6]. In the heterogeneous solubilization,
the particles are totally insoluble and the catalyst get
adsorbed on to the solid whereas in the case of homogeneous
solubilization model, the particles are sparingly soluble in
the organic phase and the particle solubility is augmented by
the phase transfer agent [PEG]. The particle size goes on
decreasing with time due to the reaction in the organic phase.
2
. Results and discussion
The reaction scheme is given by
+
ꢀ
Preliminary experiments established that the reaction was
Depending on the relative rate of transfer of [PEG K F ] in
the organic film next to the solid and the reaction of the
species, four different regimes can be identified just like the
L–L PTC [13]. These are shown in Fig. 1 and the importance
of various steps is delineated in the captions.
facile at 30 8C. To understand the enhanced rates of reaction
under these conditions, it was thought worthwhile to study
the mechanism and kinetics of this reaction. Since a typical
experiment produced 90% conversion of p-toluenesulfonyl
chloride, with 100% selectivity to the fluoride, a further
insight was obtained by studying the effect of various
parameters on the rates of reaction.
Preliminary experiments suggested that the homoge-
neous solubilization model illustrated by the S 2 type of
N
reaction of the substrate RX with the nucleophile Y of the
solid reactant MY.
The overall reaction is:
2
.1. Mechanism and kinetic model
k obs
RX
ðorgÞ
þ MYðsÞ þ PEGðorgÞ ꢀ! RYðorgÞ þ MXðsÞ
Polyethylene oxide chains form complexes with cations,
much like crown ethers, and these complexes cause the
anion to be transferred into the organic phase and to be
activated [10]. Complexation of solid alkali metal salts by
PEG is strongly dependent on both the anion and the cation
of the salt [11]. The phase transfer catalytic efficiencies of
polyethylene glycols were proven and analysed [12]. It was
observed that best catalytic efficiencies were obtained by
using medium chain length PEG [n = 7–9].
þ PEGðorgÞ
(1)
The solid reactant is in equilibrium with its solution in the
organic phase. This is the solubility of KF in the solvent in
the presence of the catalyst. It was obtained by taking a large
and known amount of KF in the solvent and catalyst and
stirring for 1 h and then filtering the solution under vacuum
and weighing the dry solids again. It was obtained
ꢀ5
ꢀ3
The first step of the reaction involves the complexation of
+
PEG with metal cation [K ] (Scheme 1) and forms [PEG
2.62 Â 10 mol cm . In the absence of the catalyst the
solubility was less
+
ꢀ
K F ], which is organophilic and is freely transported to the
bulk organic phase. There could be a resistance associated
with the transfer of this complex across the liquid film next
to solid–liquid interface. The second step involves the
K2
þ
ꢀ
½MYŠ Ð ½M Y Š
(2)
s
ðorgÞ
This represents saturation solubility of the solid in organic
liquid.
+
ꢀ
reaction of the [PEG K F ] with the reactant [RX] located in
the organic phase. There are several possibilities by which
this reaction can occur. Finally the third step involves the
+
PEG forms the complex with metal cation M
K3
þ
ꢀ
þ
ꢀ
ꢀ
½PEGŠðorgÞ þ ½M Y Š
Ð ½PEG M Y Š
(3)
ðorgÞ
ðorgÞ
transport of the co-product anion [X ], the leaving group to

G.D. Yadav, P.M. Paranjape / Journal of Fluorine Chemistry 126 (2005) 99–106
101
Fig. 1. Typical S–L PTC under homogeneous solubilization. (a) Regime 1: very slow reaction. The reaction occurs in the bulk organic phase as a homogeneous
reaction. Mass transfer effects are unimportant. (b) Regime 2: slow reaction. The reaction occurs in the bulk organic phase. No free concentration of ion pairs
+
exists in the bulk organic phase. (c) Regime 3: fast reaction. Diffusion of [Q Y ]org and its reaction with RX are steps in parallel, and the reaction occurs in the
ꢀ
+
organic liquid film next to the S–L interface. (d) Regime 4: instantaneous reaction. The reaction between [Q Y ]org and RX is so fast that they cannot coexist in
ꢀ
+
the organic phase. [Q Y ]org diffuses from the L–L interface, and RX diffuses from the bulk organic phase into the organic liquid film and react at a plane from
ꢀ
+
the interface. No free [Q Y ]org exists beyond distance l and no free RX exists beyond distance (d
ꢀ
0
ꢀ l) toward the interface. Note that for simplicity other ion
pairs are not shown.
+
ꢀ
(org)
The substance RX reacts with the complex [PEG M Y ]
according to
K5
þ
ꢀ
½
M X Š
ꢀ*½MXŠs
(6)
ðorgÞ )ꢀ
kr
þ
ꢀ
RX
þ ½PEG M Y ŠðorgÞꢀ! RYðorgÞ
PEG is thus generated repeatedly to catalyse the reaction.
The equilibrium constant K which is a sort of a solubility
ðorgÞ
e
þ
ꢀ
þ ½PEG M Y Š
(4)
(5)
ðorgÞ
parameter is defined by combining steps (2), (3), (5) and (6)
as follows:
where k is rate constant.
r
þ
ꢀ
½
M Y Š
ðorgÞ
1
=K4
þ
ꢀ
þ
ꢀ
K2 ¼
(7)
½
PEG M X Š
Ð ½PEGŠðorgÞ þ ½M X Š
ðorgÞ ðorgÞ
½MYŠs

102
G.D. Yadav, P.M. Paranjape / Journal of Fluorine Chemistry 126 (2005) 99–106
þ
ꢀ
This integral is solved by the method of partial fractions to
get the following:
½
½
½
PEG M Y Š
ðorgÞ
K ¼
(8)
3
þ
ꢀ
PEGŠ½M Y Š
ðorgÞ
ꢀ
ꢁ ꢀ
ꢁ
ꢀ
ꢁ
M
M ꢀ XA
1 ꢀ K þ K M
e
e
þ
ꢀ
ln
ꢀ
lnð1 ꢀ XAÞ
PEGŠ½M X Š
1
ðorgÞ
ðorgÞ
M ꢀ 1
¼
M
M ꢀ 1
¼
(9)
þ
ꢀ
K4
½PEG M X Š
krQ t for
0
M
6
(23)
½
MXŠ
s
K ¼
5
(10)
Eq. (12) can be further manipulated to the following to
extract both K and k :
þ
ꢀ
½
M X Š
ðorgÞ
e
r
þ
ꢀ
ꢂ
ꢃ
ꢂ
ꢃ
½
PEG M Y Š
½MXŠs
K K K
3
ðorgÞ
lnððM ꢀ X Þ=MÞ
1 ꢀ K þ K M
2
5
A
e
e
K ¼
e
¼
(11a)
(11b)
ꢀ
þ
ꢀ
K4
½MYŠ ½PEG M X Š
lnð1 ꢀ X Þ
M
s
ðorgÞ
A
ꢂ
ꢃ
ðM ꢀ 1ÞkrQ0
t
½
MYŠs
þ
ꢀ
þ
ꢀ
¼
(24)
½
PEG M Y Š
¼ Ke
½PEG M X Š
ðorgÞ
ðorgÞ
M
lnð1 ꢀ XAÞ
½
MXŠ
The rate of reaction of Eq. (4) is given by
s
A
plot of ½lnððM ꢀ X Þ=MÞ=lnð1 ꢀ X ފ versus t/
A
A
ꢀ
d½RXŠ
ln(1 ꢀ X
) should give
A
ðorgÞ
ðorgÞ
þ
ꢀ
¼
¼
kr½RXŠðorgÞ½PEG M Y Š
½MYŠs
(12)
(13)
ꢂ
ꢃ
ðorgÞ
dt
ðM ꢀ 1Þk Q
r
0
slope ¼
and
ꢀ
d½RXŠ
M
krKe
½RXŠðorgÞ
ꢂ
ꢃ
dt
½MXŠs
ðM ꢀ 1ÞKe þ 1
intercept ¼
(25)
þ
ꢀ
M
 ½PEG M X Š
ðorgÞ
But
Thus, both K and k can be obtained from the slope and
e r
intercept from the knowledge of M and Q . Further for
0
þ
ꢀ
þ
ꢀ
Q ¼ ½PEG M Y Š
þ ½PEG M X Š
ðorgÞ
0
ðorgÞ
equimolar quantities of substrate and nucleophile, the fol-
lowing form of the integrated equation results
¼
total concentration of catalyst in organic phase
ꢀ
ꢁ
XA
(
14)
þ ð1 ꢀ K Þ lnð1 ꢀ X Þ ¼ k Q t for M ¼ 1
e
A
r
0
þ
ꢀ
þ
ꢀ
1 ꢀ XA
½
PEG M X Š
¼ ½Q ꢀ ½PEG M Y Šðorgފ
(15)
ðorgÞ
0
(
26)
½
MYŠs
þ
ꢀ
½
PEG M Y Š
¼ Ke
½Q0
ðorgÞ
½
MXŠs
Eq. (15) can also be manipulated to the following:
þ
ꢀ
X =1 ꢀ X
t
ꢀ
½PEG M Y Š
Š
(16)
(17)
A
A
ðorgÞ
ꢀ
¼
krQ0
þðKe ꢀ 1Þ
(27)
lnð1 ꢀ X Þ
1 ꢀ XA
A
þ
ꢀ
þ
½
PEG M Y Š
¼ ½Q ꢀ ½PEG M Y ŠðorgފR
ðorgÞ
0
A plot of ðX =ð1 ꢀ X ÞÞ=lnð1 ꢀ X Þ versus t=lnð1 ꢀ X Þ
A
A
A
A
Q R
0
þ
ꢀ
½
PEG M Y Š
¼
(18)
(19)
will give a straight line with slope equal to k Q and intercept
r 0
ðorgÞ
1
þ R
equal to (K ꢀ 1).
e
½
½
MYŠs
The validation of the above model was verified by
conducting several experiments.
R ¼ Ke
MXŠs
The fractional conversion of RX at time t is defined by:
NRX0 ꢀ NRX
2.2. Effect of various catalysts
XA ¼
(20)
N
RX0
Different catalysts such as tetrabutyl ammonium bromide
TBAB), ethyl triphenyl phosphonium bromide (ETPB) and
where NRX is the initial moles of RX at time t = 0.
Let M ¼ NMY0 =NRX0 = initial molar ratio of solid
reactant (MY) to organic substrate (RX).
By substituting these terms in Eq. (13), the following is
obtained
(
PEG-400 were selected for the reaction under otherwise
similar concentration of catalyst at 30 8C and 1500 rpm
(Fig. 2). Out of these PEG-400 gave maximum rates of
reaction and conversion. It was conjectured that the
ineffectiveness of the quaternary salt in the overall reaction
process was due to the absence of chelating heteroatom
which can favour the process of removing ion pair from solid
matrix. Apart from high reactivity of PEG-400 as compared
to others it is very cheap (Rs. 160 kg) Thus, further
experiments were conducted with PEG-400. The selectivity
to the product p-toluenesulfonyl fluoride was 100%.
ꢀ1
þ R
ꢁ
dXA
¼
krQ0t
(21)
R
1 ꢀ X
Substituting for R, [MX] and [MY] in terms of X and M,
A
s
s
A
and then separation of variable in Eq. (21) leads to:
ꢂ
Z
ꢃ
XA
X þ K M ꢀ K X
A
e
e
A
dX ¼ krQ t
(22)
A
0
K ðM ꢀ X Þð1 ꢀ X Þ
0
e
A
A

G.D. Yadav, P.M. Paranjape / Journal of Fluorine Chemistry 126 (2005) 99–106
103
Fig. 4. Effect of catalyst loading. p-Toluenesulfonyl chloride, 0.02 mol; KF,
0
9
.04 mol; speed, 1500 rpm; acetonitrile, 46 ml; temperature, 30 8C; time,
0 min.
Fig. 2. Effect of different catalysts. p-Toluenesulfonyl chloride, 0.02 mol;
KF, 0.04 mol; speed, 1500 rpm; acetonitrile, 46 ml; temperature, 30 8C;
time, 90 min.
ꢀ
3
ꢀ3 ꢀ1
4
3
.201 Â 10 mol cm
s
which is 1.996 Â 10 times
greater than the rate of reaction. Thus the observed reaction
rate was much smaller than the mass transfer rate. Therefore
there was no mass transfer resistance associated with the
reaction and the reaction would be kinetically controlled.
2
.3. Effect of speed of agitation
The reaction was carried out at four different speeds of
agitation (Fig. 3) with PEG-400 as catalyst. There was a
significant increase in the conversion from 1000 to
2.4. Effect of catalyst loading
1
1
1
500 rpm. But it was almost constant at 1500 and
800 rpm. All subsequent reactions were carried out with
500 rpm while assessing the effect of other variables on the
The concentration of the catalyst was varied from
ꢀ
5
ꢀ5
ꢀ3
2.1739 Â 10 to 6.521 Â 10 mol cm org. (Fig. 4). It
was observed that as the concentration was increased, the
conversion increased, but above a concentration of
rate of reaction.
The observed initial rate of reaction, for a typical
experiment was equal to 1.6667 Â 10ꢀ mol cm
7
ꢀ3 ꢀ1
s
whereas the rate of mass transfer was estimated from the
knowledge of solid–liquid mass transfer coefficient (kSL-A),
4.3447 Â 10 mol cm org., there was no further increase
in the conversion. The validity of Eq. (13) was tested.
Appropriate plots were made for M = 2 as shown in Fig. 5.
There is an excellent fit for different values of catalyst
concentration. The average values of k and K were obtained
ꢀ5
ꢀ3
ꢀ
1
particle surface area (a = 611.20 cm ) and the solubility
P
of potassium fluoride in acetonitrile was measured as
ꢀ3
r
e
ꢀ5
3
ꢀ1
ꢀ1
2
coefficient (k = 0.199 cm/s) which was found from
.62 Â 10 mol cm . The solid–liquid mass transfer
as 77.1 cm mol min and 0.11, respectively.
SL-A
Sherwood number (kSL-AdP/D = 2). A limiting value of
A
2.5. Effect of mole ratio
Sherwood number was taken as 2 since the particles were
very fine. The Wilke–Chang equation was used to calculate
the bulk diffusivity. The mass transfer rate was equal to
Mole ratio of p-toluenesulfonyl chloride to potassium
fluoride (KF) was varied from 1:1 to 1:3 (Fig. 6). The
ꢀ
5
ꢀ3
catalyst loading was kept at 4.3447 Â 10 mol cm org.
The reaction rate was found to increase at the mole ratio of p-
toulenesulfonyl chloride to KF from 1:1 to 1:1.5. It was
observed that there is insignificant increase in the conversion
at mole ratio of 1:2 to 1:3. This is because of the saturation of
the binding sites available in PEG. So further addition of
potassium fluoride does not help in enhancement of the rate
of reaction. The average values of k and K were obtained as
r
e
3
ꢀ1 ꢀ1
73.216 cm mol min and 0.0257, respectively. There is
an excellent fit of the proposed model with the experimental
data (Fig. 7).
2.6. Effect of temperature
The effect of temperature was studied under otherwise
similar reaction conditions from 30 to 60 8C (Fig. 8). It was
found that the conversion increased substantially with
increase in temperature. However, there was a marginal
Fig. 3. Effect of speed of agitation. p-Toluenesulfonyl chloride, 0.02 mol;
KF, 0.04 mol; PEG-400, 0.8 g; acetonitrile, 46 ml; temperature, 30 8C; time,
90 min.

104
G.D. Yadav, P.M. Paranjape / Journal of Fluorine Chemistry 126 (2005) 99–106
Fig. 5. Determination of k
3
r
and K
e
values. p-Toluenesulfonyl chloride, 0.02 mol; KF, 0.04 mol; speed, 1500 rpm; acetonitrile, 46 ml; temperature, 30 8C; time,
ꢀ1 ꢀ1
9
0 min. k = 77.1 cm mol min ; K = 0.11.
r e
suggested that the reaction was kinetically controlled. Ke
is a sort of combination of solubility and distribution
constant of ion pairs. The Gibbs free energy value was
calculated as 185.01 kJ/mol, which shows that the equili-
brium exchange of ions and solubility are thermodynami-
cally feasible.
3. Experimental details
3.1. Experimental procedure
The reaction was studied in 5 cm i.d. fully baffled
3
Fig. 6. Effect of mole ratio of p-toluenesulfonyl chloride to KF. p-Tolue-
nesulfonyl chloride, 0.02 mol; PEG-400, 0.8 g; speed, 1500 rpm; acetoni-
trile, 46 ml; temperature, 30 8C; time, 90 min.
mechanically agitated glass reactor of 100 cm total
capacity which was equipped with a six-blade pitched
turbine impeller (1 cm diameter). The impeller was located
at a distance of 2 cm from the bottom. This arrangement
ensured excellent solid–liquid mixing for high mass transfer
rates. The assembly was kept in a water bath to maintain the
desired temperature and mechanically stirred at a known
speed with an electric motor.
increase in conversion at 60 8C over than that at 50 8C. The
same theory was again validated at all temperatures (Fig. 9).
Thus, Arrhenius plot was made and the activation energy
calculated as 36.59 kJ/mol (Figs. 10 and 11), which
Fig. 7. Validation of the model p-toluenesulfonylchloride, 0.02 mol; PEG-400, 0.8 g; speed, 1500 rpm; acetonitrile, 46 ml; temperature, 30 8C; time, 90 min.

G.D. Yadav, P.M. Paranjape / Journal of Fluorine Chemistry 126 (2005) 99–106
105
Fig. 8. Effect of temperature. p-Toluenesulfonyl chloride, 0.02 mol; KF,
0
9
.04 mol; PEG-400, 0.8 g; speed, 1500 rpm; acetonitrile, 46 ml; time,
0 min.
Fig. 11. Gibbs free energy plot.
for an hour. This procedure allowed the salts to be
continually solubilized and precipitated until a constant
particle size was achieved. (Without employing these
procedures reproducible data were difficult to achieve.)
After stirring for an hour, p-toulenesulfonyl chloride
(0.02 mol) dissolved in 21 ml of acetonitrile was added and
the mixture was stirred. A zero time sample was collected
and sampling was done periodically to get concentration–
time profiles of reactants and products.
3.2. Chemicals and catalysts
Fig. 9. Validation of model at different temperatures p-toluenesulfonyl
p-Toulenesulfonyl chloride, acetonitrile, diphenyl ether,
chloride, 0.02 mol; KF, 0.04 mol; PEG-400, 0.8 g; speed, 1500 rpm; acet-
3
3
= 78.34 cm mol min ; k
ꢀ1
ꢀ1
onitrile, 46 ml; time, 90 min. k
r
r
= 115.2 cm
ꢀ1
all of A.R. grade, were procured from M/s E. Merck Ltd.,
Mumbai. Potassium fluoride (Anhydrous LR grade) was
purchased by M/s s.d. Fine Chemicals, Mumbai. PEG-400
was obtained from S-D Fine Chemicals, Mumbai. All other
PTCs were gift samples from M/s Dishman Pharmaceuticals
and Chemicals Ltd., Ahmedabad, India.
ꢀ
1
ꢀ1
3
ꢀ1
ꢀ1
3
ꢀ1
mol min ; k
= 0.019 at 30 8C;
= 0.1324 at 60 8C.
r
= 165.09 cm mol min ; k
r
= 299.03 cm mol min
= 0.0044 at 50 8C;
;
K
e
K
e
= 0.0018 at 40 8C; K
e
K
e
Typically the reaction was carried out as follows: initially
potassium fluoride (0.04 mol) along with PEG-400
0.002 mol) and diphenyl ether (0.004 mol, used as an
(
3.3. Analysis
internal standard) in 25 ml acetonitrile was stirred at 30 8C
Analysis was performed on GC (Chemito Gas Chroma-
tograph, model 8610) by using a 2 m  3.175 mm stainless
steel column packed with 10% OV-17 on Chromosorb WHP,
coupled with a flame ionization detector. Synthetic mixtures
of the reactant and internal standard were used to calibrate
the chromatograms and quantify the data. The product was
confirmed by GC-MS.
4. Conclusion
p-Toulenesulfonyl fluoride is used as peroxygen bleach
activator. It also finds use in the treatment of Alzheimer’s
disease. The synthesis of this compound was undertaken by
using a variety of catalysts amongst which PEG-400 was
found to be the best catalyst. A complete theoretical analysis
of the process was carried out to explain the observed rate
Fig. 10. Arrhenius plot for activation energy.

106
G.D. Yadav, P.M. Paranjape / Journal of Fluorine Chemistry 126 (2005) 99–106
[
2] C.M. Starks, C.M. Liotta, M. Halpern, Phase Transfer Catalysis:
data. Both equilibrium constant and rate constant could be
calculated from the same set of data. The apparent activation
energy is 36.59 kJ/mol.
Fundamentals, Applications and Perspectives, Chapman & Hall,
New York, 1994.
[
[
[
3] Y. Sasson, R. Neumann (Eds.), Handbook of Phase Transfer Catalysis,
Blackie Academic and Professional, London, 1997.
4] E.V. Dehmlow, S.S. Dehmlow, Phase Transfer Catalysis, 3rd ed.
VCH, Weinheim, 1993.
5] G.D. Yadav, M.M. Sharma, Ind. Eng. Chem. Process Res. Dev. 20
Acknowledgements
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G.D. Yadav acknowledges Darbari Seth Endowment for
supporting the Chair. Priyanvada Paranjape acknowledges
UGC, New Delhi for an award of JRF which enabled this
work to be carried out.
[
9] G.D. Yadav, Y.B. Jadhav, Langmuir 18 (2002) 5995–6002.
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