3334. Diphosgene

Nomenclature

CAS number: 503-38-8
Carbonochloridic acid trichloromethyl ester; chloroformic acid trichloromethyl ester; trichloromethylchloroformate; trichloromethylcarbonochloridate.
C2Cl4O2; mol wt 197.83.
C 12.14%, Cl 71.68%, O 16.17%.
ClCOOCCl3.

Description and 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).

Use

In organic synthesis; as war gas.