Ethene reaction with, phosgene

Wijnen [2185,2185a] has proposed that the photolysis of phosgene provides an excellent source of chlorine atoms, and has studied the reactions between phosgene and ethene (Section 10.1.2) and phosgene and ethyne (Section 10.1.4) under photochemical conditions. No problems with secondary reactions of phosgene were encountered. 

The reaction of phosgene with ethene has been investigated by several workers [1119-1121,1579,2103]. Pace [1579] claimed that, in the presence of an aluminium(III) chloride catalyst in toluene solution, an acid chloride ClCHjCHjCOCl was produced. However, this work could not be independently confirmed [1120,2103], and no conditions were found under which the acid chloride was formed. In toluene, only products derived from reactions with the solvent were isolated [1120,1121,2103]. CICH CHjCOCl, however, is... 

The reaction between ethyne and phosgene has also been studied under photochemical conditions (>220 nm) [2185a]. As in the analogous reaction with ethene (see Section 10.1.2), the phosgene merely acts as a convenient source of chlorine radicals the principal products were CO, CHj=CHCl, 1-chloro-l, 3-butadiene, benzene and polymer trace amounts of HC Cl and CgHjCl were also detected [2185a]. 

The photolysis of phosgene in the presence of ethene gives results which are quite different from those obtained by the photochlorination of ethene with molecular chlorine, in which the main reaction product is 1,2-dichloroethane. The proposed mechanism for the phosgene reaction is given below [2185] ... 

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