Description

Diphosgene (DP), trichloromethyl chloroformate, is a clear, colorless liquid with an odor similar to phosgene. It is noncombustible, a strong irritant to the eyes and tissues, and is toxic by inhalation and ingestion. DP has a boiling point of 127°C–128°C (263°F) and a vapor pressure of 4.2 at 68°F (20°C). The liquid density is 1.65, which is heavier than water, and a melting/freezing point of 314°F (157°C). Inhalation LC50 is 3600 mg/m3 for 10 min. Effects of exposure are quite similar to phosgene gas. Its molecular formula is ClCOOCCl3, and the structure and molecular formula are shown in Figure 8.38. The DOT lists diphosgene as a 6.1 poison liquid. The NFPA 704 designation for CG is estimated to be health 4, flammability 0, reactivity 1, and special 0. It has a four-digit UN identification number of 2972.

Chemical Properties

clear colorless liquid

Uses

Reactant for preparation of:

• Cyclic carbamimidates using a monophosphine gold(i) catalyst
• N-Alkenyl and cycloalkyl carbamates as dual acting histamine H3 and H4 receptor ligands
• Prostate-specific membrane antigen-targeted anticancer prodrugs
• Potential west nile virus protease inhibitors
• Antibody-drug conjugates (ADCs)
• Erythromycin A derivatives

Uses

Trichloromethyl chloroformate is used as a reagent in the synthesis of organic compounds. It serves as a source of phosgene used in some laboratory preparations. Also, it is used as a reactant for the synthesis of cyclic carbamimidates, N-alkenyl and cycloalkyl carbamates and prostate-specific membrane antigen-targeted anticancer prodrugs. In addition, it is involved in the preparation of an erythromycin A derivatives and antibody-drug conjugates. It is utilized in the conversion of amines, carboxylic acids, formamides in to isocyanates, acid chlorides and isocyanides respectively.

Uses

In organic synthesis; as war gas.

Definition

diphosgene: A colourless liquid,ClCO.O.CCl₃, originally used in 1916by Germany in World War I as achemical warfare agent. It is nowused as a reagent in organic synthesis.See also carbonyl chloride.

General Description

Colorless liquid, odorless to fruity.

Air & Water Reactions

Decomposes slowly in water or moist air (or when inhaled) to form very corrosive hydrogen chloride gas (hydrochloric acid) and carbon monoxide.

Hazard

Toxic by inhalation and ingestion, strong irritant to tissue.

Fire Hazard

Some may burn but none ignite readily. Vapors from liquefied gas are initially heavier than air and spread along ground. Some of these materials may react violently with water. Cylinders exposed to fire may vent and release toxic and/or corrosive gas through pressure relief devices. Containers may explode when heated. Ruptured cylinders may rocket.

Safety Profile

Low toxicity by inhalation. A corrosive liquid. When heated to decomposition it emits toxic vapors of Cl-.