The invention relates to a process for producing 4,4′-dichlorodiphenyl sulfone, comprising: (I) reacting thionyl chloride, chlorobenzene and aluminum chloride forming an intermediate reaction product and hydrogen chloride; (II) mixing aqueous hydrochloric acid and the intermediate reaction product to obtain an organic phase comprising 4,4′-dichlorodiphenyl sulfoxide and an aqueous phase; (III) cooling the organic phase to a temperature below the saturation point of 4,4′-dichlorodiphenyl sulfoxide to obtain a suspension; (IV) solid-liquid-separation of the suspension to obtain crystallized 4,4′-dichlorodiphenyl sulfoxide, and mother liquor; (V) washing the crystallized 4,4′-dichlorodiphenyl sulfoxide with a carboxylic acid to obtain carboxylic acid-wet 4,4′-dichlorodiphenyl sulfoxide; (VI) reacting the washed 4,4′-dichlorodiphenyl sulfoxide and an oxidizing agent in a carboxylic acid as solvent to obtain a reaction mixture comprising 4,4′-dichlorodiphenyl sulfone and carboxylic acid; (VII) separating the reaction mixture comprising 4,4′-dichlorodiphenyl sulfone and carboxylic acid into a residual moisture comprising 4,4′-dichlorodiphenyl sulfone as crude product and a liquid phase comprising carboxylic acid.

A process for the synthesis of Dapsone and intermediates thereof are described.

A process for the synthesis of Dapsone and intermediates thereof are described.

A process for the synthesis of Dapsone and intermediates thereof are described.

The present invention relates to processes for preparing for preparing 3-(methylsulfonyl)propionitrile. The processes comprise the steps of first reacting 2-chloroethyl methyl sulfide with sodium cyanide or potassium cyanide in a solvent or a solvent mixture to form 3-(methylthio)propionitrile, and then reacting the isolated 3-(methylthio)propionitrile with acetic anhydride, acetic acid, and hydrogen peroxide to form 3-(methylsulfonyl)propionitrile.

The present invention relates to processes for preparing for preparing 3-(methylsulfonyl)propionitrile. The processes comprise the steps of first reacting 2-chloroethyl methyl sulfide with sodium cyanide or potassium cyanide in a solvent or a solvent mixture to form 3-(methylthio)propionitrile, and then reacting the isolated 3-(methylthio)propionitrile with acetic anhydride, acetic acid, and hydrogen peroxide to form 3-(methylsulfonyl)propionitrile.

The present invention relates to processes for preparing for preparing 3-(methylsulfonyl)propionitrile. The processes comprise the steps of first reacting 2-chloroethyl methyl sulfide with sodium cyanide or potassium cyanide in a solvent or a solvent mixture to form 3-(methylthio)propionitrile, and then reacting the isolated 3-(methylthio)propionitrile with acetic anhydride, acetic acid, and hydrogen peroxide to form 3-(methylsulfonyl)propionitrile.

The invention is directed to a catalyst, to a method for manufacturing a catalyst, to a method for manufacturing a bisphenol compound, and to the use of a catalyst. The catalyst of the invention comprises particles having a core and a shell, wherein the shell comprises an ion exchange resin covering the core at least in part and wherein the core has a density that is higher than the density of the ion exchange resin.

The invention is directed to a catalyst, to a method for manufacturing a catalyst, to a method for manufacturing a bisphenol compound, and to the use of a catalyst. The catalyst of the invention comprises particles having a core and a shell, wherein the shell comprises an ion exchange resin covering the core at least in part and wherein the core has a density that is higher than the density of the ion exchange resin.

The present disclosure provides, in part, a process for preparing compounds (I) having allosteric effector properties against Hepatitis B virus Cp.

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