Low Temperature Fluorination of Aerosol Suspensions of Hydrocarbons Utilizing Elemental Fluorine-'Aerosol Direct Fluorination-Indirect Syntheses of Perfluorocycloketones

摘要

Ring opening during the aerosol direct fluorination of cyclic ketones can be circumvented by the aerosol direct fluorination of the appropriate methoxycycloalkanes or the ethylene glycol ketals of the cyclic ketones followed by sulfuric acid hydrolyses of the perfluorinted analogs. Aerosol direct fluorinations of methoxycyclopentane and methoxycyclohexane produce their respective perfluoroanalogs in effluent concentration of 57% and 90% by weight and in 22% and 32% isolated yields respectively. Sulfuric acid hydrolyses at 340 to 360 C of the F-methoxycycloalkanes produced F-cyclopentanone (89% yield, 61% conversion) and F-cyclohexanone (82% yield, 28% conversion) respectively. The aerosol fluorinations of the ethylene glycol ketals of cyclopentanone and cyclohexanone produce F-dioxaspiro(4.4)nonane and F-dioxaspiro(4.5)decane in effluent concentrations of 74% and 76% by weight and in 14% and 12% isolated yields respectively. Sulfuric acid hydrolyses at 500 C produced F-cyclopentanone (45% yield, 23% conversion) and F-cyclohexanone (100% yield, 36% conversion) respectively. Physical loss of starting material caused by condensation within the aerosol fluorinator is the major reason for reduced yields. Hydrolysis yields are based on starting materials consumed and not recovered. (Author)