Hydrogen halides reaction with, phosgene

Volatile protactinium pentaehloride has been prepared in a vacuum by reaction of the oxide with phosgene at 550° C or with carbon tetrachloride at 200°C. Reduction of this at 600°C with hydrogen leads to protactinium(IV) tetrachloride, Pad. which is isostructural with uranium(IV) tetrachloride, UCI4. The pentaehloride can be converted into the bromide or iodide by heating with the corresponding hydrogen halide or alkali halide... 

In a rather eccentric process, given the propensity of such systems for halide exchange, the reaction between tantalum(V) oxide and hydrogen fluoride at 90 C in an autoclave, followed by treatment of the mixture (now a hydrated fluorotantalic acid) with phosgene at 140 "C, has been used for the synthesis of anhydrous tantalum(V) fluoride [1106] ... 

Reactions of phosgene with hydrogen halides and hydrogen cyanide... 

Reaction of phosgene with iViV-dialkylisobutyramides followed by elimination of hydrogen chloride gives vinyl halides, these substrates show high reactivity towards nucleophilic reagents, particularly on addition of silver ion. Thus electron-rich... 

The phase-transfer catalysed reaction of alkyl halides with potassium carbonate in dimethylacetamide, or a potassium carbonate/potassium hydrogen carbonate mixture in toluene, provides an excellent route to dialkyl carbonates without recourse to the use of phosgene [55, 56], An analogous reaction of acid chlorides with sodium hydrogen carbonate in benzene, or acetonitrile, produces anhydrides (3.3.29.B, >80%), although there is a tendency in acetonitrile for aliphatic acid chlorides to hydrolyse yielding the acids [57]. 

Catalysis. Catalytic properties of the activated carbon surface are useful in both inoiganic and oiganic synthesis. For example, the fumigant sulfuryl fluoride is made by reaction of sulfur dioxide with hydrogen fluoride and fluorine over activated carbon (114). Activated carbon also catalyzes the addition of halogens across a carbon—carbon double bond in the production of a variety of oiganic halides (85) and is used in the production of phosgene... 

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