Phosgene Substitutes and Homologues

Because of its reputation as a noxious material, there is occasionally an advantage to be obtained by using a phosgene substitute or homologue. This Chapter describes some of the alternatives that are available, and considers what possible advantages may be gained by their 

Exceptions to this rule-of-thumb may occur if either diphosgene (trichloromethyl 

The principal uses of phosgene in organic synthesis are in the areas of chlorination, chloroformylation, carbonylation and dehydration, and possible substitutes will now be considered in each of these areas. 

In many cases, phosgene provides a unique method for chlorination, and many 

Oxalyl chloride (ethanedioyl dichioride) can be an effective, alternative, chloroformylating agent to phosgene. The reaction of oxalyl chloride with diphenyl ketene, for example, proceeds under milder conditions than with phosgene to give the identical organic product [1938]  

---