1. Features and parameters (Feature)

Item Parameter value

Chemical name Dimethyl disulfide (DMDS)

CAS number 624-92-0

Appearance Colorless to light yellow transparent liquid

Purity ≥99%

Water content <0.1%

Packing specification 200kg industrial barrel/custom container

2. Industry application scenarios (Advantage)

Pesticide efficiency enhancement: Replace traditional chloropicrin and reduce soil residual toxicity

Petrochemical efficiency enhancement: Oil refining catalyst passivator, reduce equipment corrosion loss

Pharmaceutical synthesis: Key sulfur-containing intermediates, reaction selectivity increased by 30%

Physical and chemical properties

Dimethyl disulfide (dimethyl disulfide) industrial product purity ≥ 99%, flammable yellow liquid, with sulfur smell, melting point -84.7℃, boiling point 109.6℃. Vapor pressure 3.0×106mPa (20℃). KowlgP=1.91. Henry constant 105Pa·m3/mol (calculated). Relative density 1.062 (20℃). Solubility in water (20℃) 2.7g/L, miscible with most organic solvents (15~25℃). Stability: Stable when heated to 300℃, unstable when heated in oxidants. Freezing point 16℃.

Chemical properties

Light yellow transparent liquid. Has a foul odor. Insoluble in water, miscible with ethanol, ether and acetic acid.

Uses

1. Used as solvent and pesticide intermediate, fuel and lubricant additive, coking inhibitor for ethylene cracking furnace and oil refining unit, etc.

2. Used as solvent and pesticide intermediate, and also the main raw material for methylsulfonyl chloride and methylsulfonic acid products

3. Dimethyl disulfide, also known as dimethyl disulfide, is used to synthesize the intermediates of organophosphorus insecticides such as fenthion and fenamiphos, p-methylthio-meta-cresol, and p-methylthiophenol, which is the intermediate of thiopropylphos, and is also used as a purifier for solvents and catalysts.

4. Used as a passivator for solvents and catalysts, pesticide intermediate, coking inhibitor, etc. Dimethyl disulfide reacts with cresol to generate 2-methyl-4-hydroxyanisyl sulfide, which is then condensed with O,O-dimethyl sulfide phosphoryl chloride in an alkaline medium to obtain fenthion. This is a highly efficient and low-toxic organophosphorus insecticide with excellent control effects on rice borers, soybean borers and gadfly larvae. It can also be used as a veterinary drug to eliminate cattle fly maggots and cattle ticks.

Production method

1. Obtained by the reaction of dimethyl sulfate and sodium disulfide. Add sulfur powder to sodium sulfide solution under stirring, heat to 80-90℃, react for 1h, and cool to about 30℃; drip dimethyl sulfate into the reactor, continue to react for 2h, then distill, let stand for stratification, separate the waste alkali liquid, and then distill to obtain the finished product.

2. Dimethyl disulfide is synthesized by dimethyl sulfate method in industry. Na2S+S→Na2S2Na2S2+(CH3)2SO4→CH3SSCH3+Na2SO4Put solid sodium sulfide and water into the reactor, heat, control the temperature at 50-60℃, dissolve the sodium sulfide, then add equimolar sulfur in batches, keep warm for 1h, cool to 45℃, start dripping dimethyl sulfate, keep the reaction temperature between 40-45℃, keep warm for 1h after adding, and then dimethyl disulfide can be evaporated. In addition, dimethyl disulfide can also be synthesized by methyl mercaptan method.

3. Produced by the reaction of methylmagnesium iodide and disulfur dichloride. Produced by the reaction of disodium disulfide and sodium methyl sulfate. Produced by the reaction of methyl bromide and sodium thiosulfate to obtain sodium methyl thiosulfate, which is then heated.

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