Triphosgene

Triphosgene is a chemical compound commonly used as a solid, safer-to-huse phosgene substitute in organic synthesis. Its chemical formula is C3Cl6O3, and it is typically encountered as a white crystalline solid at room temperature. Because of its solid state and relatively low volatility, triphosgene can be easier to handle than phosgene gas in laboratory settings. It is soluble in a range of organic solvents such as dichloromethane and chloroform, but is not appreciably soluble in water.

Triphosgene functions as a controlled source of phosgene and can release phosgene on hydrolysis or heating. This property underpins its primary utility as an acylating reagent for the formation of carbamates, carbonates, and related compounds. In organic synthesis, triphosgene is used to convert amines into isocyanates or to form carbamoyl chlorides and carbonates, providing a practical alternative to phosgene in laboratory-scale reactions and in polymer chemistry.

Safety and handling are central considerations when using triphosgene. It is toxic and an irritant, with hazards resembling those of phosgene; exposure to vapors or decomposition products can affect the eyes, skin, and respiratory system. It should be stored and handled under strictly dry, well-ventilated conditions, typically in a closed container and away from moisture. Appropriate personal protective equipment and use within a fume hood are advised.

See also: phosgene, isocyanates, carbamates, carbonates.