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Method of producing diaryl acetylenes Invention relates to a method of producing diaryl acetylenes of general formula , where R=aryl; R1=aryl, by reacting an organotin compound with aryl iodides in the medium of an organic solvent, in the presence of a catalyst - a palladium (II) complex, characterised by that the organotin compound used is tin tetraalkynylides and the reaction takes place at temperature 60-100°C. |
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4,4'-difluorobenzophenone synthesis method Present invention relates to a method for synthesis of 4,4'-difluorobenzophenone, the main raw product for synthesis of aromatic polyester-ketones. The method involves a first step where fluorobenzene reacts with formaldehyde under conditions for catalysis with organic sulphonic acids to form difluorodiphenylmethane. The product is extracted and oxidised with nitric acid at the second step to 4,4'-difluorobenzophenone. |
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Method for preparing hexafluorobutadiene and 1,2-dichlorohexafluorocyclobutane Invention relates to methods for preparing fluoro-containing monomers and methods for preparing halogen-containing cyclic compounds, namely: to preparing hexafluorobutadiene and 1,2-dichlorohexafluorocyclobutane (C4Cl2F6-cyclo). Method for preparing hexafluorobutadiene is carried out by pyrolysis of chlorotrifluoroethylene followed by dechlorination of 1,2-dichlorohexafluorobutene-3 in the presence of zinc in a solvent. The parent chlorotrifluoroethylene is subjected for pyrolysis at temperature from 505°C to 600°C for 0.5-15 s. Prepared pyrolysate is condensed at temperature from 0°C to -10°C and then condensate is rectified to isolate fraction boiling at 59.0-59.5°C and containing 1,2-dichlorohexafluorocyclobutane (C4F6Cl2). Fraction boiling at 63.5-64°C and containing 1,2-dichlorohexafluorobutene-3 is subjected for dechlorination in polar solvent medium at temperature 37-50°C. Compounds not condensed at the condensation stage are recovered to pyrolysis. Method provides carrying out pyrolysis of chlorotrofluoroethylene with conversion 50-70% and to obtain hexafluorobutadiene and 1,2-dichlorohexafluorocyclobutane simultaneously. Method exhibits technological effectiveness and involves essentially 3 main stages only. |
Another patent 2551065.