Phosgene

Abstract

Phosgene is a colorless, low boiling liquid which is manufactured by reaction of carbon monoxide and chlorine over activated carbon. It is a very toxic substance, and extensive safety procedures and equipment have been developed to help ensure the safe handling of phosgene. Phosgene is an important and widely used intermediate for chemical synthesis. Its primary use is for the manufacture of polyisocyanates for the polyurethane industry. Other uses are the production of polycarbonate, chloroformates, agrochemicals, and intermediates for pharmaceuticals and dyestuffs. Vol. 18, pp. 645–655, 91 refs. to August 1995.

Selective Oxidative Carbonylation of Aniline to Diphenylurea with Ionic Liquids

“…Moreover, ureic derivatives have a wide spectrum of biological activity and have been applied extensively as agrochemicals, dyes, antioxidants, and resin precursors and as key intermediates in organic synthesis, for example, in the production of isocyanates . In this context, the oxidative carbonylation of amines to obtain ureas (Scheme ) has received much interest over the past 50 years as an alternative to the traditional phosgenation process . The reaction is performed in the presence of a metal catalyst or organocatalyst, an oxidizing agent such as I 2 or O 2 /air, and CO pressure.…”

The Solvation and Dissociation of 4-Benzylaniline Hydrochloride in Chlorobenzene

“…Following work announced by Sumitomo, recent studies have examined a range of new materials that display favorable properties as efficient Deacon catalysts. − In principle, these improvements in the operation of the Deacon reaction could be applied to convert waste HCl produced in the industrial synthesis of aryl isocyanates to Cl 2 , which could then be used as a feedstock for phosgene production. Phosgene synthesis typically involves the reaction of CO and Cl 2 over a high-surface-area carbon catalyst. , That body of work is supplemented by studies investigating the feasibility of phosgene production via the oxy-chlorination of CO. − Although the aforementioned studies on a new generation of Deacon catalysts and CO oxy-chlorination routes to phosgene are more closely linked to initiatives to help close the chlorine cycle, the work reported here primarily seeks to evaluate the feasibility of a new route to workup hydrochloride salt byproducts associated with large-scale isocyanate unit operations.…”