Process for preparing 3-(methylsulfonyl)propionitrile

1. A method for preparing 3-(methylsulfonyl)propionitrile, comprising the steps of:

(a) mixing and reacting 2-chloroethyl methyl sulfide with sodium cyanide or potassium cyanide in a solvent mixture of water and a water-immiscible organic solvent at 20-100° C.,

(b) allowing the reaction mixture of (a) to settle and to separate into an aqueous phase and an organic phase,

(c) isolating 3-(methylthio)propionitrile in the organic phase,

(d) mixing the isolated 3-(methylthio)propionitrile with acetic anhydride, acetic acid, and hydrogen peroxide at 25-42° C. to form 3-(methylsulfonyl)propionitrile, and

(e) isolating 3-(methylsulfonyl)propionitrile from the reaction mixture of (d).

2. A method for preparing 3-(methylsulfonyl)propionitrile, comprising the steps of:

(a) mixing and reacting 2-chloroethyl methyl sulfide with sodium cyanide or potassium cyanide in a solvent mixture of water and a water-immiscible organic solvent at 20-100° C.,

(b) allowing the reaction mixture of (a) to settle and to separate into an aqueous phase and an organic phase,

(c) isolating 3-(methylthio)propionitrile in the organic phase,

(d) mixing the isolated 3-(methylthio)propionitrile with acetic anhydride,

(e) reacting the mixture of (ii) with an aqueous solution comprising acetic acid, acetic anhydride and hydrogen peroxide at 25-42° C. to form 3-(methylsulfonyl)propionitrile, and

(f) isolating 3-(methylsulfonyl)propionitrile from the reaction mixture of (e).

3. The method of claim 1 , wherein the water-immiscible organic solvent is ethyl acetate or diethyl ether.

4. The method of claim 2 , wherein the water-immiscible organic solvent is ethyl acetate or diethyl ether.