Synthesis of 2,2,2-trifluoroethanethiol

Abstract

A method of making CF3CH2SH, comprising a step of reacting CF3CH2X, wherein X is halide or tosylate, with MSH, where M is an alkali metal such as Na or K, to yield CF3CH2SH. More specifically, a method of making CF3CH2SH, a step of reacting CF3CH2CI with a molar excess of NaSH in a reaction medium of one or more polar organic solvents at a temperature of from about 70 C to about 110 C for a time of from about 1 to about 5 hours.

1 . A method of making CF 3 CH 2 SH, comprising a step of reacting CF 3 CH2X, wherein X is a leaving group selected from the group consisting of halide and tosylate, with MSH, wherein M is an alkali metal. 
     
     
         2 . The method of  claim 1 , wherein X is Cl. 
     
     
         3 . The method of  claim 1 , wherein M is Na. 
     
     
         4 . The method of  claim 1 , wherein the reacting is carried out in at least one organic solvent. 
     
     
         5 . The method of  claim 1 , wherein the reacting is carried out in at least one polar organic solvent. 
     
     
         6 . The method of  claim 1 , wherein the reacting is carried out in at least one solvent selected from the group consisting of dimethylsulfoxide, dimethylacetamide, N-methylpyrrolidone, dimethylformamide, ethylene glycol and combinations thereof. 
     
     
         7 . The method of  claim 1 , wherein the reacting is carried out in the presence of a phase transfer catalyst. 
     
     
         8 . The method of  claim 7 , wherein the phase transfer catalyst is ammonium salt. 
     
     
         9 . The method of  claim 8 , wherein the tetraalkyl ammonium salt is selected from the group consisting of tetra alkyl ammonium salts such as tetra-n-butylammonium bromide, methyltrioctylammonium chloride and mixtures thereof. 
     
     
         10 . The method of  claim 1 , wherein MSH is reacted in molar excess with CF 3 CH 2 X. 
     
     
         11 . The method of  claim 1 , wherein at least two moles of MSH per mole of CF 3 CH 2 X are reacted. 
     
     
         12 . The method of  claim 1 , wherein the reacting is conducted at a temperature within a range of about 70° C. to about 110° C. 
     
     
         13 . The method of  claim 1 , wherein CF 3 CH 2 X and MSH are reacted for a period of time of from about 1 hour to about 5 hours. 
     
     
         14 . The method of  claim 1 , wherein the reacting is carried out at a pressure above atmospheric pressure. 
     
     
         15 . The method of  claim 1 , wherein H 2 S is additionally present during the reacting of CF 3 CH 2 X and MSH. 
     
     
         16 . The method of  claim 1 , wherein the reacting is carried out in a sealed reactor with the CF 3 CH 2 X and the MSH present in a liquid reaction medium and wherein sufficient H 2 S is present in the sealed reactor such that the partial pressure of H 2 S above the liquid reaction medium is greater than the saturation partial pressure. 
     
     
         17 . The method of  claim 1 , wherein reacting CF 3 CH 2 X and MSH yields a reaction product mixture comprised of CF 3 CH 2 SH and at least one by-product selected from the group consisting of (CF 3 CH 2 ) 2 S 2  and (CF 3 CH 2 ) 2 S. 
     
     
         18 . The method of  claim 14 , additionally comprising a further step of separating CF 3 CH 2 X from the reaction product mixture. 
     
     
         19 . The method of  claim 14 , additionally comprising a further step of separating the at least one by-product from the reaction product mixture. 
     
     
         20 . The method of  claim 16 , additionally comprising a further step of reacting the at least one by-product separated from the reaction product mixture with a hydrogenating agent to form CF 3 CH 2 SH. 
     
     
         21 . A method of making CF 3 CH 2 SH, comprising a step of reacting CF 3 CH 2 Cl with a molar excess of NaSH in a reaction medium comprised of one or more polar organic solvents at a temperature of from about 70° C. to about 110° C. for a time of from about 1 to about 5 hours. 
     
     
         22 . The method of  claim 18 , wherein H 2 S is additionally present during the reacting of CF 3 Ch 2 Cl and NaSh.