Patent GB-990649-A (GB)
Title: A process for the production of fluorine-containing compounds
IPC: C07F7/12
Filed: 1962-07-10
Abstract: Fluorine-containing compounds of elements of the first and second periods of the fourth to sixth groups of the Periodic System are obtained by reacting a chlorine, bromine, or iodine compound of the element with at least one saline fluoride, the reaction being effected in a salt melt of melting point 200-500 DEG  C. The melt may consist of at least one saline fluoride, with or without at least one salt which is not a fluoride, in which case the fluoride may be at least partly in suspension.  Additionally, catalytic quantities of at least one salt, the cations of which can have at least two different valencies, may be present.  The melt may consist of a mixture of an alkali metal fluoride and an alkaline earth metal fluoride, or a mixture of at least one alkali metal halide and at least one alkaline earth metal or zinc halide, in which melt an alkali metal and/or an alkaline earth metal fluoride is partly suspended and partly dissolved.  The reaction is preferably effected in the vapour phase. Examples describe the preparation of trimethyl silane fluoride from trimethyl silane chloride, thionyl fluoride from thionyl chloride, sulphuryl fluoride from sulphuryl chloride, COF2 and COFCl from phosgene, CFCl3, CF2Cl2, and CF3Cl from CCl4, phosphorus trifluoride from phosphorus trichloride, and thiofluorophosgene from thiophosgene.ALSO:Fluorocarbons are obtained by reacting a chlorine, bromine, or iodine compound of carbon with at least one saline fluoride, the reaction being effected in a salt melt of melting point 200 DEG -500 DEG  C.  The melt may consist of at least one saline fluoride, with or without at least one salt which is not a fluoride, in which case the fluoride may be at least partly in suspension. Additionally, catalytic quantities of at least one salt, the cations of which can have at least two different valencies, may be present. The melt may consist of a mixture of an alkali metal fluoride and an alkaline earth metal fluoride, or a mixture of at least one alkali metal halide and at least one alkaline earth metal or zinc halide, in which melt an alkali metal and/or an alkaline earth metal fluoride is partly suspended and partly dissolved.  The reaction is preferably effected in the vapour phase.  Examples describe the preparation of CFCl3, CF2Cl2 and CF3Cl from CCl4, and CF2Cl2, CF3Cl and CF3CF2Cl from thiophosgene.ALSO:Fluorosilanes are obtained by reacting a chlorine, bromine, or iodine compound of silicon with at least one saline fluoride, the reaction being effected in a salt melt of melting point 200-500 DEG  C.  The melt may consist of at least one saline fluoride, with or without at least one salt which is not a fluoride, in which case the fluoride may be at least partly in suspension. Additionally, catalytic quantities of at least one salt, the cations of which can have at least two different valencies, may be present.  The melt may consist of a mixture of an alkali metal fluoride and an alkaline earth metal fluoride, or a mixture of at least one alkali metal halide and at last one alkaline earth metal or zinc halide, in which melt an alkali metal and/or an alkaline earth metal fluoride is partly suspended and partly dissolved.  The reaction is preferably effected in the vapour phase.  Example 1 describes the preparation of trimethyl silane fluoride from trimethyl silane chloride, small quantities of dimethylsilane difluoride also being obtained.