Patent GB-776073-A (GB)
Title: Improvements in or relating to reaction of olefins with perfluoro acids
IPC: C07C7/17
Filed: 1954-07-28
Abstract: The invention comprises reacting an olefinic compound with a perfluorocarboxylic acid to form an ester.  The perfluorocarboxylic acid may be trifluoroacetic acid, pentafluoropropionic acid, heptafluorobutyric acid, tetrafluorosuccinic acid, or fully fluorinated malinic, maleic, benzoic, phthalic or cyclohexanecarboxylic acid.  The olefinic compound may be an aliphatic olefin ranging from ethylene, propylene, and the butenes to octadecenes, or a non-conjugated diolefin such as pentadiene, hexadiene, octadiene, a cyclodiene, or a cyclic olefin such as cyclopentene, cyclohexene and methyl cyclohexene.  The diolefins react to form a diester or an unsaturated monoester.  The reaction temperature is between - 15 DEG  C. and 300 DEG  C.  The esters may be converted to alcohols and the starting fluoroacid or a derivative thereof by saponification, alcoholysis or hydrolysis.  The esters may be used to alkylate phenols and paraffins.  The perfluorocarboxylic acids react selectively with tertiary olefins, i.e. unsaturated hydrocarbons in which at least one of the carbon atoms of the double bond is devoid of hydrogen, and may be used for the selective separation of tertiary olefins from mixtures which may contain secondary olefins as well as other hydrocarbons.  The tertiary olefins may also be converted to esters by reaction with a complex of the perfluoroacid and a complex-forming ether, such as dioxane, isopropyl ether sec.-butyl ether or n-butyl ether.  In examples: (1) trifluoroacetic acid is reacted with 1-octene to form sec.-octyl trifluoroacetate, with 2-octene to form 2- and 3-octyl trifluoroacetates, and with 1-dodecane to form dodecyl trifluoroacetate; (2) aqueous trifluoroacetic acid solution is reacted with cyclohexene and cyclopentene to form cyclohexyl and cyclopentyl trifluoroacetates, respectively; (3) tetramethyl ethylene is reacted with trifluoroacetic acid to form 2,3-dimethylbutyl-2-trifluoroacetate which is hydrolysed with NaOH to form 2,3-dimethylbutanol-2; (4) 1-octene is reacted with heptafluoro-butyric acid to form octylheptafluorobutyrate which is saponified with NaOH to form dl-octano-2; (5) sec.-butyl heptafluorobutyrate is formed from 2-butene and heptafluorobutyric acid; (6) 1,5-hexadiene is reacted with heptafluorobutyric acid to form hexenyl heptafluorobutyrate and hexane - 2,5 - diol - di-(heptafluorobutyrate); (7) isopropyl pentafluoropropionate is prepared from propylene and perfluoropropionic acid, and hydrolysed to isopropyl alcohol; (8) the sec.-octyl trifluoroacetate of Example 1 is converted to octanol-2 by alcoholysis with methanol or n-propanol in the presence of hydrogen chloride or p-toluene sulphonic acid; (9) ethylene and propylene are reacted with trifluoroacetic acid in the presence of sulphuric acid as catalyst; (10) butene-1 butene-2, pentene-2 and trimethylethylene are reacted with trifluoroacetic acid, with or without sulphuric acid present, and t.-amyl trifluoroacetate is saponified, or alcoholysed with methanol, to give t.-amyl alcohol; (11) 1-methyl-1-cyclopentane is reacted with trifluoroacetic acid, and the product is treated with methanol and sodium to obtain methyl trifluoroacetate and 1-methyl-1-cyclopentanol; (12) mixtures of n-octane with octene-1 and toluene with cyclohexene are treated with trifluoroacetic acid to separate the unsaturated components as esters; (13) tetrafluorosuccinic acid is reacted with ethylene to obtain diethyl perfluorosuccinate, and with propylene to obtain di-isopropyl perfluorosuccinate, the esters being then hydrolysed to give ethyl and isopropyl alcohols; (14) t.-butyl trifluoroacetate is used to alkylate phenol to obtain t.-butyl phenol, to alkylate p-cresol, and to alkylate isopenane to obtain a mixture of hydrocarbons including 2-methyl pentane; (15) a mixture of trimethylethylene and pentene-2 is treated with trifluoroacetic acid the trimethylethylene being selectively converted to t.-amyl trifluoroacetate; (16 to 20) mixtures of (a) trimethylethylene with octene-2 and n-paraffins, (b) tetramethylethylene with cyclohexene and n-hexene, (c) 1-methyl-1-cyclopentene with n-hexene, and (d) 4-methyl-1-cyclohexene, and (e) a catalytically cracked naphtha, are each treated with trifluoroacetic acid to demonstrate that the tertiary olefins are selectively converted to esters; (21) a complex of trifluoroacetic acid and 1,4-dioxane is reacted with isobutylene under pressure; (22) heptafluorobutyric acid is added to a mixture of 1-methyl-1-cyclopentene and n-hexane, the tertiary olefin reacting with the acid; (23) a catalytically cracked naphtha containing tertiary olefins, other olefins and other hydrocarbons, is treated with trifluoroacetic acid, the tertiary olefins forming esters which are reacted with sodium methylate in methanol to obtain methyl trifluoroacetate and tertiary alcohols, which are listed.