Dimethyl sulfate (DMS) is a highly efficient methylation reagent with the molecular formula (CH3 O) ₂ SO ₂, and appears as a colorless oily liquid at room temperature. Its methylation ability is irreplaceable in the fields of medicine, pesticides, and fine chemicals, with a year-on-year increase of 8.5% in domestic demand in 2022.

Core application areas

1. Pharmaceutical synthesis: Used for methylation reactions of drug intermediates such as bupropion and caffeine, and is prohibited from being combined with acidic drugs containing phenolic hydroxyl groups (such as salicylic acid);

2. Pesticide preparation: key reagents for the synthesis of insecticides/fungicides such as chlorpyrifos and fipronil;

3. Spice manufacturing: The volatile components are extracted by SPME method for the synthesis of jasmine essence, and the key aroma substances are separated by DBWAX chromatographic column;

4. Materials industry: Core raw material for methyl methacrylate (acrylic) methylation process.

Technical advantages and risks

Although DMS with CAS 77-78-1 is toxic, its high-temperature stability is outstanding: the conversion efficiency reaches 98% at 180 ℃, significantly better than dimethyl carbonate (DMC has a decomposition rate of over 60% at the same temperature). The use of DMS instead of iodomethane in the synthesis of intermediate of Yejunzuo can reduce the methylation cost by 30% (total yield 36%).