Dimethyl sulfate (DMS) is a chemical reagent that is irritating, corrosive, toxic, and carcinogenic, and has been used as a chemical weapon. However, its boiling point is relatively high, reaching over 180 degrees, and compared to iodomethane, DMS still has a certain level of safety.

Dimethyl sulfate belongs to the highly toxic category. Has strong stimulation and corrosiveness, and has delayed biological effects. Flammable when exposed to heat, open flames, or oxidants. Commonly used as a methylation reagent, dimethyl sulfate is a reagent that can methylate DNA. After methylation, DNA can be degraded at the methylation site. Anhydrous methanol is added to chlorosulfonic acid or fuming sulfuric acid cooled to -10 ℃ and distilled under reduced pressure.

Main applications

In organic synthesis, dimethyl sulfate is often used as a methylation reagent; Under the action of alkali, it can methylate hydroxyl, carboxyl, amino, thiol, carbocation, and imine, making it a low-cost and relatively useful methylation reagent; It, like iodomethane, can methylate human DNA, so it is important to take precautions during use to avoid causing excessive harm to the body. Currently, in organic synthesis, low toxicity dimethyl carbonate and methyl trifluoromethanesulfonate are used as substitutes.

Meanwhile, due to the high boiling point of DMS, it can withstand higher reaction temperatures, which iodomethane does not possess; Iodine methane has a low boiling point of only 40 degrees and is easily volatile, making it highly prone to steam formation when heated. Therefore, for the methylation reaction that requires heating, it is recommended to use a methylation reagent - dimethyl sulfate (DMS).