Swarts reactions

Antimony tnfluoride is a mild fluorinating reagent. However, it is much mote effective ia the Swarts reactions where its effectiveness as a fluorinating reagent is dramatically iacteased by addition of CI2, Bt2, or SbCl to the reaction mixture (2). Antimony tnfluotide can be used for the replacement of chlorine or bromine ia halocatbons, hydtohalocatbons, and nonmetal and metal haUdes. Typical reactions can be summarized as follows ... 

Although many syntheses of chlorofluorocarbons and hydrochlorofluorocarbons have been published, those actually used in manufacturing processes are limited. By far the most important is the original Swarts reaction [5]. 

Swarts reaction org chem The reaction of chlorinated hydrocarbons with metallic fluorides to form chlorofluorohydrocarbons, such as CCI2F2, which is quite inert and nontoxic. svarts re,ak-shan ... 

The synthesis of alkyl fluorides Is best accomplished by heating an allyl chlorlde/bromlde In the presence of a metallic fluoride such as AgF, HggFg, CoFg or SbFg. The reaction is termed as Swarts reaction. 

The chlorofluorocarbon compounds of methane and ethane are collectively known as freons. They are extremely stable, unreactlve, non-toxic, non-corrosive and easily liquefiable gases. Freon 12 (CCI2F2) Is one of the most common freons In Industrial use. It Is manufactured from tetrachloromethane by Swarts reaction. These are usually produced for aerosol propellants, refrigeration and air conditioning purposes. By 1974, total freon production In the world was about 2 billion pounds annually. Most freon, even that used In refrigeration, eventually makes Its way Into the atmosphere where It diffuses unchanged Into the stratosphere. In stratosphere, freon Is able to Initiate radical chain reactions that can upset the natural ozone balance (Unit 14, Class XI). 

Our resolution to this dilemma has been to work out a compact procedure based upon the fluorinating agent SbF3 catalyzed by SbCl5 using acetonitrile as a solvent (i.e., the Swarts reaction).6... 

Chlorine atoms in (trichloromethyl)benzenes which have fluoro, chloro, dichloromethyl, chloroformyl, cyano, isocyanato, jV-phthalimino or methyl substituents in the ring are substituted by fluorine using antimony(III) fluoride (Swarts reaction).3 4 2-(Trifluoromethyl)phen-yl isocyanate, 4-chloro-2-(trifluoromethyl)phenyl isocyanate, 2,4- and 2,5-bis(trifluoro-methyl)phenyl isocyanate, and 2,4-bis(trifluoromethyl)-l,5-phenylenc diisocyanate can be obtained in this way.5... 

The Swarts reaction is used to prepare 4-(trifluoromethyl)aniline by treating A -[4-(trichlo-romethyl)phenyl]phthalimide with antimony(IIl) fluoride followed by saponification of the i ntermediatc (trifluoromethyl)imide.7... 

SWARTS REACTION. Fluorination of organic polyhalides with antimony trifluoride (or zinc and mercury fluorides) in the presence of a trace of a pentavalent antimony salt. 

Sulfuryl chloride, 1 114 Sulfuryl fluoride, 6 158 Swarts reaction, 4 134... 

The generally accepted mechanism of the Swarts reaction assumes the formation of an antimony (V) halofluoride. The following reactions are postulated in connection with the catalysts mentioned above ... 

It has been observed that a definite threshold temperature exists below which the Swarts reaction will not proceed. The best results are obtained if the desired product is removed as fast as it is formed. More highly fluorinated products may be obtained if the reaction products are refluxed in the reactor. 

Hydrogen fluoride is used in the Swarts reaction on a commercial scale to regenerate the antimony (III) fluoride. The compound to be fluorinated and anhydrous hydrogen... 

The fluorination of an aromatic trichloroinethyl group is also achieved with antimony(III) fluoride in molar ratios ranging from antimony(III) fluoride/(trichloromcthyl)benzene 5 1 to 2 1 129 135 jjjjj chemistry (the Swarts reaction) has been extended to substituted aromatics, with some examples given by the formation of 7, 8, 9 and lO. - ... 

A Swarts reaction and related processes (halogen exchange using HF)... 

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