Dimethyl sulfate is an important methylation reagent widely used in organic synthesis fields such as pharmaceuticals, pesticides, dyes, and fragrances. The following is a detailed classification of its main uses:

1. Application in the field of medicine

Dimethyl sulfate is used as a highly efficient methylation reagent in drug synthesis to introduce methyl groups. Specific examples include:

Rotigotine: a drug used to treat Parkinson's disease, with a key step in its synthesis achieved through O-methylation reaction.

Relytoline: an antiepileptic drug that relies on it to complete N-methylation reactions.

Avimopan: Used for postoperative gastrointestinal function recovery, synthesized through C-methylation reaction.

Cimetidine: the first H ₂ receptor antagonist used for the treatment of peptic ulcers, involving S-alkylation in synthesis.

Chlorpheniramine Fumarate: a second-generation antihistamine drug prepared by quaternization reaction.

Neostigmine Methanesulfate: an anticholinesterase drug, the final step requires N-methylation to form a quaternary ammonium salt.

2. Pesticides and agricultural chemicals

As a methylation reagent, it is used for synthesizing various insecticides and herbicides, such as:

Methamidophos and Acephate (insecticides).

Paraquat and cyclohexanone (herbicides).

By modifying the molecular structure, pesticide activity can be enhanced, such as glyphosate and dicamba.

3. Dye and fragrance industry

Used for the synthesis of azo dyes to enhance the stability and sun resistance of color molecules.

As an intermediate of spices such as vanillin, its molecular properties are altered through methylation reactions.

4. Other industrial uses

Solvent: Used for dissolving aromatic hydrocarbons.

Preparation of dimethyl sulfoxide: as a precursor substance.

Laboratory reagents: determination of coal tar substances.

Security Tips

Dimethyl sulfate has strong toxicity and carcinogenicity (IARC Class 2A), and strict protection is required during operation (such as gas masks and goggles). Storage should be sealed away from light.