Organic Process Research & Development
Article
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compound and minimized formation of the undesired sulfone.
This approach can also be extended to the production of other
prazole compounds.
ASSOCIATED CONTENT
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S
* Supporting Information
(i) Conversion of sulfide and selectivity of sulfoxide at different
residence times for the case of the multipoint dosing approach.
(ii) Method for the estimation of residence time for the
multipoint dosing approach. This material is available free of
AUTHOR INFORMATION
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Corresponding Author
(19) The substrates and the product used for the experiments had
poor solubility in other water immiscible solvents viz. dichloro-
methane. Hence, methanol and chloroform were tried as solvents. In
most of the cases methanol was used as solvent, and in some cases a
mixture of methanol and chloroform were used as solvents.
Chloroform was used as a solvent in very few experiments.
Notes
The authors declare the following competing financial
interest(s): CSIR’s Internal Disclosure Number: 78NF2009
and Patent Applications US20120203003A1 and
EP2451810A1.
(20) The flow rate of the sulfide solution was maintained constant at
the first inlet, while the oxidizing agent was distributed at different
locations. The flow rate of the stock solution was maintained such that
the mole ratio of the reactants used for the reaction remained the same
as discussed earlier. From the values of the flow rates at individual
locations, the local velocity in individual segments was estimated. Since
the volume of individual segments between two inlet points was fixed,
the residence time entirely depended upon the velocity of fluid in that
segment. The sum of residence time for every segments yielded the
mean residence time for a given flow distribution combination. Thus, if
[QS,1] is the flow rate of the sulfide at the first inlet, and [QO,1], [QO,2],
[QO,3], and [QO,4], are the flow rates of the oxidizing agent at inlets 1−
4, and V1, V2, V3, and V4 are the volumes of the individual segments of
the reactor between two inlets for the oxidizing agent, then
ACKNOWLEDGMENTS
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We thank the Industrial Consortium for Microreaction
Technology (NCL, Pune) and the Centre of Excellence for
Microreactor Engineering (NCL, Pune) for the financial
support for this work. We are grateful to Dr. Srinivas Hotha
(IISER, Pune) for his valuable suggestions on restructuring the
discussion in the manuscript.
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⎤
⎦
residence time for segment 1: t = V/ QS,1 + Q O,1
(
1
1
⎤
⎦
residence time for segment 2: t = V / QS,1 + Q O,1 + Q O,2
(
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residence time for segment 3:
t = V / QS,1 + Q O,1 + Q O,2 + Q O,3
⎤
⎦
(
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t = V / QS,1 + Q O,1 + Q O,2 + Q O,3 + Q O,4
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