Triphosgene

Triphosgene (bis(trichloromethyl) carbonate (BTC)) is a chemical compound with the formula OC(OCCl3)2. It is used as a solid substitute for phosgene, which is a gas and diphosgene, which is a liquid. Triphosgene is stable up to 200 °C. Triphosgene is used in a variety of halogenation reactions. Triphosgene is named this way because one equivalent of triphosgene behaves like three equivalents of phosgene. Triphosgene generates two equivalents of phosgene in situ, while the carbonate has the same reactivity as one equivalent of phosgene.