Title: Diphosgene
CAS Registry Number: 503-38-8
CAS Name: Carbonochloridic acid trichloromethyl ester
Additional Names: chloroformic acid trichloromethyl ester; trichloromethylchloroformate; trichloromethylcarbonochloridate
Molecular Formula: C2Cl4O2
Molecular Weight: 197.83
Percent Composition: C 12.14%, Cl 71.68%, O 16.17%
Line Formula: ClCOOCCl3
Literature References: Used in synthesis as substitute for phosgene, q.v. Prepn by photochlorination of methyl formate: W. Hentschel, J. Prakt. Chem. 36, 209 (1887); F. Grignard et al., C.R. Hebd. Seances Acad. Sci. 169, 1074 (1919); eidem, ibid. 1143; by photochlorination of methyl chloroformate: A. Kling et al., ibid. 1046; K. Kurita, Y. Iwakura, Org. Synth. 59, 195 (1980). Effect on air-blood barrier in rabbits, toxicity: E. Klika, A. Mysliveckova, Folia Morphol. (Prague) 19, 5 (1971), C.A. 75, 3433c (1971). Use in synthesis of isocyanides: G. Skorna, J. Ugi, Angew. Chem. Int. Ed. 16, 259 (1977).
Properties: Suffocating liquid. bp 128°. bp50 49°. d15 1.664. nD22 1.45664. Stable at room temp, decomposes to phosgene at ~300°C. LC100 in rabbits (10-20 minutes exposure to vapor): 0.9 mg/l air (Klika, Mysliveckova).
Boiling point: bp 128°; bp50 49°
Index of refraction: nD22 1.45664
Density: d15 1.664
Toxicity data: LC100 in rabbits (10-20 minutes exposure to vapor): 0.9 mg/l air (Klika, Mysliveckova)
Use: In organic synthesis; as war gas.
Dipicrylamine Dipin Dipipanone Dipiproverine Dipivefrin

CAS number 503-38-8 YesY
ChemSpider 21154424 YesY
RTECS number LQ7350000
Jmol-3D images Image 1
Molecular formula C2Cl4O2
Molar mass 197.82 g/mol
Appearance liquid at room temperature
Density 1.65 g/cm3
Melting point −57 °C
Boiling point 128 °C
Solubility in water insol.
R-phrases 26/28-34
S-phrases 26-28-36/37/39-45
Main hazards toxic
Flash point 32 °C; 90 °F; 305 K
Related compounds
Related compounds COCl2, Cl2
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Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
Infobox references

Diphosgene is a chemical compound with the formula ClCO2CCl3. This colorless liquid is a valuable reagent in the synthesis of organic compounds. Diphosgene is related to phosgene but is more conveniently handled because it is a liquid, whereas phosgene is a gas.