Ethane reaction with, phosgene

The gas phase reaction of phosgene with ethane-1,2-diol over activated charcoal results in the formation of 1,2-dichloroethane with a yield of about 70% at 210 C higher temperatures caused the decomposition of the diol [1C186]. 

Reaction of ethane-1,2-diol with phosgene in the liquid phase gives the... 

The early chemical literature concerning the reactions of phosgene with aldehydes is fraught with confusion. The product of the reaction of phosgene with ethanal, for example, has been variously reported as a polymer [1078b], a gem-dichloride [582], a chloroformate [322], or (ludicrously) a material isomeric with vinyl chloride (chloroethene) [685c,887,1164a]. Only recently has this situation been satisfactorily resolved [1765]. 

The reaction of phosgene with butanal under substantially similar conditions to those used for the reaction of phosgene with ethanal gave smaller yields of the 1,1-dichloro-derivative, and the reaction of phosgene with gaseous chloral, CCI3CHO, over activated... 

Probably the simplest polymer formation reaction involving phosgene is that with the dihydric aliphatic alcohols, such as ethylene, propylene or butylene glycol viz. ethane-1,2-diol, propane-1,3-diol or butane-1,4-diol) this reaction results in the formation of linear, wax-like polymers suitable for the impregnation of materials requiring water barrier properties [1133]. 

Depending upon the reaction conditions, ethanal can combine with phosgene to produce 1,1-dichloroethane, chloroethene, vinyl chloroformate or 1-chloroethyl chloroformate (see Section 10.3.3.1). However, imder conditions which produce 1,1-dichloroethane from phosgene and ethanal (charcoal catalyst, 150 C), carbonyl difluoride reacts (using a charcoal catalyst impregnated with caesium fluoride) to produce a mixture of the saturated 1 -fluoroethyl fluoroformate and the unsaturated vinyl fluoroformate (see Section 13.14.6.3.1). Thus, the COFj/CHjCHO/charcoal system is unstable with respect to dehydrofluorination, whilst the COClj/CHjCHO/charcoal system is unstable with respect to decarboxylation ... 

Catalytic reagents are necessary for phosgene generation in other decomposition reactions. Thus, treatment of tetrachloroethene carbonate with tertiary alkylamines at room temperature, or above, causes a catalytic rearrangement to ethane-1,2-dioyl chloride and phosgene, as indicated in Table 5.6 [588,1377]. This reaction is also catalysed, but less... 

The reaction is accompanied by disproportionation (see Section 16.1.8.2), and as a result both 1,1-dichloroethane and CH3CHC10C(0)C1, were detected from the further reactions of the phosgene with ethanal [ICI117]. The same reactions occur, but to a much lesser degree, when carried out in an empty tube or in the presence of a silica catalyst [ICI117]. 

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