Sulfoxides reaction with, phosgene

Flammable Liquid, Corrosive SAFETY PROFILE Poison by inhalation. Moderately toxic by ingestion. A human systemic irritant by inhalation. Violent hydrolysis reaction with water or steam produces heat, acetic acid, HCl, and other corrosive chlorides. May decompose during preparation. Dangerous fire hazard when exposed to heat or flame. Explosion hazard by spontaneous chemical reaction with dimethyl sulfoxide or ethanol. Also incompatible with PCI3. When heated to decomposition it emits highly toxic fumes of phosgene and Cl . To fight fire, use CO2 or dry chemical. See also CHLORIDES. 

Barton devised a new method for the oxidation of primary alcohols to aldehydes involving in the first step conversion to the alkyl chloroformate (1) by adding a solution of the alcohol in ether to ether saturated with phosgene (15-20% w./v.) the solvent is removed at reduced pressure. If the alcohol is hindered, quinoline is added as catalyst and the quinoline hydrochloride removed by filtration. The next step, reaction with dimethyl sulfoxide, is attended with evolution of carbon... 

HAZARD RISK Dangerous fire hazard when exposed to heat or flame contact with strong oxidizers may cause fire vapors may flow to distant ignition sources and flash back forms explosive mixtures with powdered sodium or phosphorus trichloride and sodium violent reaction with silver perchlorate and dimethyl sulfoxide closed containers exposed to heat may explode decomposition emits toxic gases of hydrogen chloride, phosgene, carbon monoxide, carbon dioxide NFPA Code H 2 F 3 R 0. 

The maiin domain of oxidation with dimethyl sulfoxide is the conver-sionofprimary alcoholsinto aldehydes andofsecondaryalcoholsintoketones. These reactions are accomplished under very mild conditions, sometimes at temperatures well below 0 °C. The reactions require the presence of acid catalysts such as acetic anhydride [713, 1008, 1009], trifluoroacetic acid [1010], trifluoroacetic anhydride [1011, 1012, 1013], trifluorometh-anesulfonic acid [1014], phosphoric acid [1015, 1016], phosphorus pentox-ide [1006, 1017], hydrobromic acid [1001], sulfur trioxide [1018], chlorine [1019, 1020], A -bromosuccinimide [997], carbonyl chloride (phosgene) [1021], and oxalyl chloride (the Swem oxidation) [1022, 1023, 1024], Dimethyl sulfoxide also converts sufficiently reactive halogen derivatives. into aldehydes or ketones [998, 999] and epoxides to a-hydroxy ketones at -78 °C [1014]. 

A modification of alcohol oxidation with dimethyl sulfoxide is the reaction of DMSO with alkyl chloroformates, which are formed from alcohols and phosgene (equations 220 and 221) [1021]. 

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