| 摘要 |
a ,a -dialkyl branched carboxylic acids or esters thereof are prepared by reacting an olefine, branched at the double bond, or in a modification a tert-alcohol, with carbon monoxide and water or alcohol, under super-atmospheric pressure in the presence of a catalyst, (ROH2)(BF4) (R = H or a methyl radical), in a solution in ROH containing 50% or more of HBF4. Solutions containing 50% to 70% and 50% to 60%, by weight of HBF4 in water and alcohol respectively are preferred, and the process may be continuous and include a diluent. Examples describe the preparation of a ,a -dimethyl valeric acid from 2-methyl-pentene-1, with minor amounts of olefine polymers and higher carboxylic acids also produced, a -methyl-a -ethyl caproic acid from 2-ethylenehexene, trimethyl acetic acid from isobutylene, and from a mixture of tert-butanol and 2-ethylhexene, the methyl ester of a -methyl-a -ethylcaproic acid from 2-ethylhexene-1, and ethyl pivalate from tert-butanol.ALSO:Catalysts comprising hydrogen tetrafluoroborate in a complex with water or alcohol containing 50% or over by weight of HBF4, are used in the preparation of a ,a -dialkyl branched carboxylic acids or esters thereof by reacting an olefine branched at the double bond, or in a modification a tert.-alcohol, with carbon monoxide and water or alcohol under super-atmospheric pressure. The complex, (ROH2)(BF4), where R = H or a methyl radical, may be prepared by mixing BF3.nCH5OH (2,8 > n > 2) with anhydrous hydrofluoric acid; dissolving HBO2 in concentrated anhydrous hydrofluoric acid; introducing boron trifluoride into aqueous hydrofluoric acid of a suitable concentration; and by diluting H3O(BF4) with an alcohol. |
