Phosgene-boron chloride

Chlorodifluoroamine has been prepared by reaction of difluoro-amine with boron trichloride,1 phosgene (carbonyl chloride),2 or hydrogen chloride 2 treating a mixture of sodium azide and sodium chloride with fluorine 3 reaction of chlorine trifluoride with ammonium fluoride 4 reaction of chlorine with diflu oro-amine in the presence of potassium fluoride 5 and photolysis of tetrafluorohydrazine and sulfinyl chloride (thionyl chloride).6... 

Phosgene can be employed in a variety of metal-recovery operations, eg, in the recovery of platinum, uranium, plutonium, and niobium (69—73). Phosgene has been proposed for the manufacture of aluminum chloride, beryllium chloride, and boron trichloride (74—76). Phosgene has been patented as a stabilizer, either by itself or in combination with thionyl chloride, for Hquid SO2 (77). 

Liquid perchloryl fluoride is a typical nonpolar solvent. Most inorganic and organic salts are insoluble in it. Conversely, most covalent, essentially nonpolar substances, boiling within about 50°G of perchloryl fluoride, are completely miscible, e.g., chlorine, boron trifluoride, sulfur hexafluoride, silicon tetrafluoride, phosgene, nitrous oxide, chlorine trifluoride, chlorofluorocarbons, silicon tetrachloride, sulfuryl chloride, dinitrogen tetroxide, and thionyl chloride 106). 

Boron trichloride can be prepared by high temperature chlorination of boron trioxide, boric acid, metal borates or other boron compounds. Chlorine, hydrogen chloride, phosgene, silicon tetrachloride, metal chlorides, carbon... 

Several catalysts have been recommended for the N-acetylation of carbazole with acetic anhydride boron trifluoride, phosphorus pentoxide, concentrated sulfuric acid, zinc chloride, and phosphoric acid all gave 9-acetylcarbazole in moderate to good yield. 9-Acetylcarbazole can also be prepared using the Vilsmeier complex of N,N-dimethylacetamide and phosgene. ... 

Dehydration Alumina (see also Dihydropyrane, preparation). Boric acid. Boron triSuoride. N-Bromoacetamide-Pyridine-SOj. Dicyclohexylcarbodiimide. Diketene. Dimethylform-amide-Thionyl chloride. Dimethyl sulfoxide. Ethylene chlorophosphite. Florisil. Girard s reagent. Hydrobromic acid. Iodine. Mesyl chloride-Sulfur dioxide. Methyl chlorosulfite. Methylketene diethylacetal. Naphthalene-d-sulfonic acid. Oxalic acid. Phenyl isocyanate. Phosgene. Phosphorus pentoxide. Phosphoryl chloride. Phthalic anhydride. Potassium bisulfate. Pyridine. Thionyi chloride. Thoria. p-Toluenesulfonic acid. p-Toluenesulfonyl chloride. Triphenylphosphine dibromide. 

Phosgene and boron(III) chloride are miscible in all proportions [1329], as predicted earlier [738a] and the phase diagram for the COClj-BClj system (Fig. 9.3) reveals a eutectic point at -142.3 C (74.4 mole % COCIj) and no evidence for any complex formation. Moreover, the vapour pressure - composition isotherm (0 C) for this system (Fig. 9.4) shows a positive deviation from Raoult s law (although Henry s law appears to be well obeyed [649]), indicating the presence of unfavourable interactions between phosgene and boron(III) chloride [376]. Thus, the purification of boron(HI) chloride from traces of phosgene will not be complicated by the formation of a thermodynamically stable complex. 

The reaction between boron(III) oxide (or boric acid, borax, kernite or colemanite) and phosgene in a molten salt (AlClj/NaCI) has been patented as a commercial route to boron(III) chloride [148] ... 

The practicability of this process must be severely hampered by the problems of purification caused by the separation of mixtures of phosgene and boron(IIl) chloride, as described in Section 9.1.2.2. 

Boron is reported to react with phosgene between 500 and 600 C (in the presence of an excess of sodium chloride) according to [1950a] ... 

The reaction of phosgene with copper has been used to purify boron(III) chloride (see Section 9.1.2.2) [1218a]. Copper does not react with phosgene at room temperature [735], but does react between 260 and 400 C, with an activation energy of 100 kJ mol, to give copper(I) chloride [809] ... 

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