Diphosgene trichloromethyl chloroformate

Diphosgene, trichloromethyl chloroformate C13C0C(0)C1 Reported as an alternative to the use of oxalyl chloride with the advantage of being a dense liquid with low volatility262... 

Diphosgene (Trichloromethyl chloroformate), CICOOCCI0, Mol. wt. 197.85, b.p. 128°, 49°/50 mm. toxic, asphyxiating gas used in the first world war as a poison gas. This reagent is generally prepared by chlorination hv) of methyl formate or methyl chloroformate. 

Oxazolidinones 593, which represent potential chiral auxiliaries, have been prepared with diphosgene (trichloromethyl chloroformate) [418, 419). 

An article entitled Facile Conversion of Carboxamides to Nitriles [1053] describes the ready conversion of alkyl, benzylic, aryl, and heteroaryl carboxamides bearing various functionalities to the corresponding nitriles in good yields of 76-96% using liquid diphosgene (trichloromethyl chloroformate) as the dehydrating agent. In many cases, the procedure does not require an extraction step, and hence offers a very simple work-up. 

Trichloromethyl chloroformate (diphosgene) is used as a safe substitute for highly toxic phosgene gas. The latter is generated in situ by addition of catalytic amounts of tertiary amines or amides, or active carbon. Diphosgene also disproportionates to 2 equivalents of phosgene on heating above 250°C. 

R Katakai, Y Iizuka. An improved rapid method for the synthesis of N-carboxy a-amino acid anhydrides using trichloromethyl chloroformate. (diphosgene). J Org Chem 50, 715, 1985. 

Scheme 9 Reaction of an Amino Acid with Trichloromethyl Chloroformate (Diphosgene) To Produce N-Carboxyanhydrides...

The preference of the Germans during the war of 1914-18 for employing trichloromethyl chloroformate (diphosgene) rather than... 

Green Cross Gases. This includes substances with a high vapour tension and great toxic power on the respiratory tract phosgene, trichloromethyl chloroformate (diphosgene), chloro-picrin, etc. 

The reversibility of the decomposition of Diphosgene into carbon tetrachloride and carbon dioxide is still a controversial topic. However, the production of phosgene by reaction of carbon tetrachloride and carbon dioxide over catalysts such as Lewis acids was recently claimed in Russian patents (Ref. 32). The reaction is assumed to proceed through the formation of trichloromethyl chloroformate or bis(trichloromethyl) carbonate. 

Trichloromethyl chloroformate (DP, diphosgene) was first used in the summer of 1915. It eventually replaced monochloromethyl chloroformate in German gas shells and was used extensively through the end of the war. 

Beilstein Handbook Reference) BRN 0970225 Carbonochloridic acid, trichloromethyl ester Difosgen Diphosgen Diphosgene EINECS 207-965-9 Formic acid, chloro-, trichloromethyl ester HSDB 371 Methanol, trichloro-, chloroformate Perchloromethyl formate Superpalite Trichlormethylester kyseliny chlormravenci Trichloromethyl chloroformate. A poison gas. Liquid mp = -57° bp = 128° d n 1,6525 very soluble in EtOH, Et20. 

Sigurdsson et al. developed the synthesis of isocyanates from aliphatic amines [21]. Thus, the reaction of an aliphatic amine with trichloromethyl chloroformate (diphosgene) in the presence of Proton Sponge (1) (2 equiv.) at 0°C gave isocyanate in 81% yield. Azide isocyanate was synthesized from azide amine by means of a similar procedure by Keyes et al. [22] (Scheme 8.8). 

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... 

Diisocyanates are usually synthesized by phosgenation of the corresponding diamines. A tabulation of diisocyanates synthesized up to 1972 with pertinent methods of synthesis is available (11). Instead of the toxic phosgene gas, the liquid trichloromethyl chloroformate (diphosgene) (12) or the solid bistrichloromethyl carbonate (triphosgene) (13) can be used in the laboratory (see PHOSGENE). Also, oligomeric t-butylcarbonates are used to convert diamines into diisocyanates (14). 

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