Chlorosulfonyl isocyanate

Synonyms：CSI; Sulfurisocyanatidoyl chloride

CAS No.：1189-71-5

EINECS No.：214-715-2

Molecular Formula：CClNO₃S

Molecular Weight：141.5336

Structural Formula：

Standard：

Properties：This product is a colorless, transparent liquid with a pungent odor. It is highly corrosive and strongly irritant to the respiratory tract and skin. It is hygroscopic and forms fumes when exposed to air. Upon contact with water, it reacts violently and decomposes into sulfamic acid, hydrogen chloride, and carbon dioxide. It is insoluble in water but soluble in non-polar or weakly polar organic solvents such as ozonolane, chlorinated hydrocarbons, ethers, and acetonitrile. Melting Point: −44 ~−43 °C; Boiling Point: 107~108 °C; Flash Point: >110 °C (closed cup); Relative Density: 1.626 g/cm³ (25 °C)

Uses：Chlorosulfonyl isocyanate is an important raw material for the synthesis of sulfonylurea herbicides (such as metsulfuron-methyl and bensulfuron-methyl) as well as a variety of pharmaceutical intermediates. In industrial production, it typically reacts with aromatic amines to form sulfonylurea-type intermediates. This type of reaction is widely applied in the synthesis of insecticides (e.g., thiamethoxam), herbicides (e.g., oxasulfuron, pyribambenz-sodium, and pyrithiobac-sodium), and pharmaceutical intermediates such as sulfonylurea-based antidiabetic drugs. Leading global companies including Bayer, BASF, and Syngenta utilize chlorosulfonyl isocyanate as a key building block in the production of sulfonyl-containing agrochemical active ingredients. In addition, chlorosulfonyl isocyanate is also used in the preparation of paper processing additives and lithium battery electrolytes.

Storage：Store in a cool, dry and well-ventilated place. Keep away from heat sources, fire sources, and direct light.

Packing：50kg or 80kg steel-plastic composite barrel