Diphosgene

Source: Wikipedia, the free encyclopedia.
Diphosgene
Diphosgene
Diphosgene
Names
Preferred IUPAC name
Trichloromethyl carbonochloridate
Other names
Trichloromethyl chloroformate, surpalite
Identifiers
3D model (
JSmol
)
ChemSpider
ECHA InfoCard
 100.007.242 Edit this at Wikidata
EC Number
  • 207-965-9
RTECS number
  • LQ7350000
UNII
  • InChI=1S/C2Cl4O2/c3-1(7)8-2(4,5)6 checkY
    Key: HCUYBXPSSCRKRF-UHFFFAOYSA-N checkY
  • InChI=1/C2Cl4O2/c3-1(7)8-2(4,5)6
    Key: HCUYBXPSSCRKRF-UHFFFAOYAO
  • ClC(=O)OC(Cl)(Cl)Cl
Properties
C2Cl4O2
Molar mass 197.82 g/mol
Appearance liquid at room temperature
Density 1.65 g/cm3
Melting point −57 °C (−71 °F; 216 K)
Boiling point 128 °C (262 °F; 401 K)
insoluble, reacts
Hazards
Occupational safety and health (OHS/OSH):
Main hazards
 highly toxic, maybe corrosive; asphyxiant
GHS labelling:
GHS05: CorrosiveGHS06: Toxic
Danger
H300, H301, H314, H330
P260, P264, P270, P271, P280, P284, P301+P310, P301+P330+P331, P303+P361+P353, P304+P340, P305+P351+P338, P310, P320, P321, P330, P363, P403+P233, P405, P501
Flash point 32 °C (90 °F; 305 K)
Related compounds
Related compounds
 COCl2, Cl2
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
checkY verify (what is checkY☒N ?)

Diphosgene is an organic

toxicity
, but is more conveniently handled because it is a liquid, whereas phosgene is a gas.

Production and uses

Diphosgene is prepared by radical chlorination of methyl chloroformate under UV light:[1]

Cl-CO-OCH3 + 3 Cl2 —(hv)→ Cl-CO-OCCl3 + 3 HCl

Another method is the radical chlorination of methyl formate:[2]

H-CO-OCH3 + 4 Cl2 —(hv)→ Cl-CO-OCCl3 + 4 HCl

Diphosgene converts to phosgene upon heating or upon

acid chlorides, and formamides into isocyanides
. Diphosgene serves as a source of two equivalents of phosgene:

2 RNH2 + ClCO2CCl3 → 2 RNCO + 4 HCl

With α-amino acids diphosgene gives the acid chloride-isocyanates, OCNCHRCOCl, or N-carboxy-amino acid anhydrides depending on the conditions.[3]

It hydrolyzes to release HCl in humid air.

Diphosgene is used in some laboratory preparations because it is easier to handle than phosgene.

Role in warfare

Diphosgene was originally developed as a

gas masks
in use at the time.

Safety

Diphosgene has a relatively high vapor pressure of 10 mm Hg (1.3 kPa) at 20 °C and decomposes to phosgene around 300 °C. Exposure to diphosgene is similar in hazard to phosgene.

See also

References

  1. ^ Keisuke Kurita and Yoshio Iwakura (1979). "Trichloromethyl Chloroformate as a Phosgene Equivalent: 3-Isocyanatopropanoyl Chloride". Organic Syntheses. 59: 195; Collected Volumes, vol. 6, p. 715.
  2. ^ Lohs, K. H.: Synthetische Gifte; Berlin (east), 1974 (German).
  3. doi:10.1002/047084289X
    .
  4. ISBN 978-1-84603-151-9
    .

External links
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