Method for making dimethyl sulfone from dimethyl sulfoxide and hydrogen peroxide
First Claim
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1. A method for making crystalline dimethyl sulfone comprising:
- (a) simultaneously adding dimethyl sulfoxide and an aqueous solution of hydrogen peroxide to a preheated, stainless steel reaction vessel precharged with an aqueous solution of dimethyl sulfone wherein the dimethyl sulfone and aqueous solution of hydrogen peroxide is added at a rate sufficient to maintain the reaction temperature below about 120°
C. (b) distilling water from the reaction mixture;
(c) then adding water to the reaction mixture to form a dilute reaction solution;
(d) heating and filtering the heated dilute reaction solution;
(e) cooling the dilute reaction solution to crystallize out the dimethyl sulfone; and
(f) filtering or centrifuging the crystallized dimethyl sulfone.
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Abstract
The present invention provides a process for synthesizing dimethyl sulfone by the oxidation of dimethyl sulfoxide with hydrogen peroxide.
19 Citations
14 Claims
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1. A method for making crystalline dimethyl sulfone comprising:
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(a) simultaneously adding dimethyl sulfoxide and an aqueous solution of hydrogen peroxide to a preheated, stainless steel reaction vessel precharged with an aqueous solution of dimethyl sulfone wherein the dimethyl sulfone and aqueous solution of hydrogen peroxide is added at a rate sufficient to maintain the reaction temperature below about 120°
C.(b) distilling water from the reaction mixture;
(c) then adding water to the reaction mixture to form a dilute reaction solution;
(d) heating and filtering the heated dilute reaction solution;
(e) cooling the dilute reaction solution to crystallize out the dimethyl sulfone; and
(f) filtering or centrifuging the crystallized dimethyl sulfone. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A method for making flaked dimethyl sulfone comprising:
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(a) simultaneously adding dimethyl sulfoxide and an aqueous solution of hydrogen peroxide to a preheated, stainless steel reaction vessel precharged with an aqueous solution of dimethyl sulfone at a rate sufficient to maintain the reaction temperature below about 120°
C.;
(b) distilling water from thc reaction mixture;
(c) cooling the reaction mixture to below 80°
C.;
(d) adjusting the pH of the reaction mixture to about between 8 and 9 with aqueous caustic;
(e) distilling water from the reaction mixture at atmospheric pressure followed by distilling at a vacuum of at least 40 mm Hg and then followed by distilling at a vaccum of 20-30 mm Hg to provide a concentrated reaction mixture, (f) distilling dimethyl sulfone from the concentrated reaction mixture at about 160-175°
C. as a colorless oil that solidifies upon cooling; and
(g) flaking the dimethyl sulfone to provide a flowable dimethyl sulfone. - View Dependent Claims (11, 12, 13, 14)
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Specification