Potassium iodide phosgene

Various cells are available for the detection of phosgene. In one example [2093a], the test gas is fed into a solution of potassium iodide, and the liberated iodine reduced at the cathode (c/. Section 3.2.1.2). Ion-selective electrodes have also been adapted for the... 

A similar reaction occurs between phosgene gas and solid potassium iodide [1606]. 

This method has been applied to a monomer synthesis (2.20).61 The quaternary ammonium salt is used as a phase transfer catalyst. The potassium iodide converts the starting chloride to a more reactive iodide in situ. The alcohol traps the intermediate isocyanate before it can react with the small amount of water that has to be present. If no methanol is present, the corresponding urea is formed in up to 87% yield. If only 0.3 equivalent of water is used, the product is the iso-cyanurate, the cyclic trimer of the isocyanate. Where n = 1, the isocyanatoethyl methacrylate is a useful monomer now made with phosgene (2.21).62 Dow has patented a route from ethanolamine plus a dialkyl carbonate, followed transesterification to a methacrylate carbamate, which is py-rolyzed to the isocyanate (2.22) in 50% yield.63... 

---