Phosgene generation

CO were estimated at 126 and 63 p.p.m., respectively [1178]. The quantity of phosgene formed from the thermal decomposition of 1 g of CHj=CHCl in a CH,=CHCl-air mixture between 100 and 1000 "C is illustrated in Table 3.9 [1178] phosgene generation would therefore not be an important factor in a road tanker fire [ICI38]. 

Phosgene generation is automatically controlled by the downstream demand, with a turn-down ratio of 15 1 (production range of 40-600 kg h ). 

Phosgene generation can be too rapid to constitute a convenient synthesis. For example, careful heating of the peroxide CCl jCOOOH can result in the formation of phosgene, as indicated in Table 5.6. This reaction, however, can proceed violently and may... 

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... 

Treatment of a eutectic mixture of LiCl, KCl and K S at 380-400 C with phosgene generates carbon oxide sulfide in 75% yield [653] ... 

The quenching of Xe(6s, 3p ) metastable atoms by phosgene has been studied [1146,1844], and the vibrational energy transfer monitored [2004]. The reaction of excited xenon atoms (3 or 3p ) th phosgene generates XeCl(B,C), the emission from which, XeCl(B-.X ) and XeCl(C-A), has enabled vibrational relaxation and transfer between the B and C states to be studied in some detail [263,558]. 

Figure 1.13 Process flow ofthe phosgene generation section of a phosgene generator of Davy ProcessTechnology. Source adapted from Cotarca and Eckert [55].

One of the serious drawbacks of the Wittig reaction is the unavoidable production of triphenylphosphane oxide in stoichiometric quantities. Whilst its direct reduction with boron, aluminium or silicon hydrides would be possible, these reagents are too expensive for a viable process. In fact, distilled triphenylphosphane oxide is reacted with phosgene, generated in situ, to give the corresponding dichloride, which is then reduced with metals, like aluminium. [55]... 

Scheme 2.3. Process flow diagram of the phosgene generation section of a phosgene generator from Davy Process Technology (DPT) [49],...

This section deals with the reactions of amino compounds with phosgene generated from its common source or phosgene equivalents, by a direct transfer of the chlorocarbonyl group, giving carbamoyl chlorides. Reactions of imines and other unsaturated (cyclic) nitrogen compounds with phosgene will be discussed later. 

Contains one cartridge for Safe Phosgene Generation, 0.02 mol, one gas-tight adapter with tubing, one dosimeter badge + paper, and instructions. 

Keteniminium salts undergo [2-1-2] cycloaddition reactions with unreactive olefins, such as ethylene, cyclopentene, cyclohexene and styrol to give cyclobutane ammonium salts 23, which are readily hydrolyzed to give cyclobutanones 24. Likewise, reaction with acetylene derivatives affords cyclobutenylidene ammonium salts 25, which are also readily hydrolyzed to give the cyclobutenones 26. Some of the [2-1-2] cycloadducts obtained from keteniminium salts and olefines are shown in Table 4.17. The keteniminium salts are easily synthesized from suitable dimethylamides and phosgene, or trifluoromethanesulfonic acid anhydride. The reaction of the amide with phosgene generates a chloro compound 21, which is in equilibrium with the ketenimine salt 22. 

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