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Sulfur tetrafluonde-hydrogen

Treatment of 2,5 and 2,4-furandicarboxylic acids with sulfur tetrafluonde in an excess of hydrogen fluoride leads simultaneously to conversion of the carboxylic groups into trifluoromethyl groups and addition of two fluorine atoms to the furan ring to give highly fluorinated diastereoisomersof2,5-dihydrofuran [225,226,227] (equations 117 and 118)... [Pg.249]

Cyclic ethylene carbonate and its halogeno derivatives are converted into 2 2 difluoro 1,3 dioxolanes, which are useful as inhalation anaesthetics by treatment with sulfur tetrafluonde m an anhydrous hydrogen fluoride solution at 100-150 °C [239] (equation 126)... [Pg.252]

A nonconventional synthesis of the known inhalation anaesthetic, 2-bromo-2 chloro-l,l,l-trifluoroethane (Halothane), based on the reaction of ethyl 1,2 di bromo-l,2-dichloroethyl ether with anhydrous hydrogen fluoride and sulfur tetrafluonde, has been patented The reaction presumably involves cleavage of the ether linkage, followed by fluorination of the intermediate bromochloroacetyl halide with sulfur tetrafluonde, ethyl halides are the by-products [2] (equation 2)... [Pg.199]

Hydroxybenzoic acids are easily converted into hydroxybenzotrifluondes by treatment with sulfur tetrafluonde in a hydrogen fluoride solution under mild conditions [215] An exception is salicylic acid, which becomes a resin, however, a 70-75% yield of 2-hydroxybenzotrifluonde can be obtained by carrying out the fluonnation in a mixture of three parts of hydrogen fluoride and one part of benzene [216] (equation 110)... [Pg.246]

Esters of carboxylic acids are resistant toward sulfur tetrafluoride up to 300 °C. However, in the presence of an excess of hydrogen fluoride, they react like the acids to give trifluoromethyl compounds [187,235] In contrast, esters of highly fluorinated acids or alcohols react with sulfur tetrafluonde in a hydrogen fluoride solution under mild conditions without cleavage of the ester bond and give products of the replacement of carbonyl oxygen by fluorine a,a-difluoroethers [235, 236, 237, 238] (equations 124 and 125). [Pg.251]


See other pages where Sulfur tetrafluonde-hydrogen is mentioned: [Pg.234]    [Pg.250]    [Pg.234]    [Pg.251]    [Pg.239]   


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