S- trifluoromethylation

B) Preparation of S-Trifluoromethyl-2,4-Disulfamylaniline—The 5-trifluoromethylaniline-2,4-disulfonyl chloride obtained in step (A) is taken up in ether and the ether solution dried with magnesium sulfate. The ether is removed from the solution by distillation, the residue is cooled to 0°C, and 60 ml of ice-cooled, concentrated ammonia water is added while stirring. The solution is then heated for one hour on a steam bath and evaporated... 

Bismuth sodium triglycollamate 3 J5 -BisO-(p-nitrobenzoyl)-2 -deoxy-S-(trifluoromethyl) uridine a/Xfll-J rif luorothymidine Bis(phenyleneoxy) cyclohexane Clinofibrate... 

S-(Trifluoromethyl)diphenyIsulfonium triflate (29) and S -(trifluoro-methyl)phenoxathiinium triflate (32) were synthesized as shown in Eqs. 5 and 6. 

Kinetic Parameters for the Trifluoromethylation of Aniline with 5-(Trifluoromethyl)dibenzothiophenium Triflate (17), S-(Trifluoromethyl)diphenylsulfonium Triflate (29), AND 5-(Trifluoromethyl)-3,7-DINITRODIBENZOTHIOPHENIUM TrIFLATE (39) IN DMF-d7 AT 25°C... 

Numerous S -fluoroaryl or S -fluoroalkyl derivatives of cysteine have been described. Thus, fluorination of S -benzyl cysteine has been performed with XeFa- The photochemical trifluoromethylation of cysteine, or of its disulfide, affords optically pure S -trifluoromethyl cysteine. Some electrophilic halogenated compounds (such as trifluorochloroethylene) are able to achieve the 5-fluoroalkylation of cysteine. 

Pentane Octafluoro-2,2.4.4-tetraki.s-[trifluoromethyl]- ElOa. 167f-(20H - 20F)... 

Ethyl 3,3-bi s(trIfluoromethyl)-propenoate, AJ6T Ethyl bromide, AA80 Ethyl bromoacetate, AC93 Ethyl 4-bromobutanoate, AH83 Ethyl bromoethanoate, AC93 Ethyl (bromomethyl)acrylate, AH56 Ethyl 2-(bromomethyl)propenoate, AH56... 

Ten mmoles of S-trifluoromethyl trifluoromonothioperoxyacetate are photolyzed for hour through Pyrex glass with a Hanovia Utility ultraviolet quartz lamp (140 watts), which produces bis(trifluoromethyl) sulfide and carbon dioxide quantitatively. Pure bis(trifluoromethyl) sulfide is retained in a —120°C. slush bath (diethyl ether) while carbon dioxide slowly sublimes into a —183°C. bath during trap-to-trap distillation. 

Melting Point and Solubility of Salts of an Antimalarial Drug, a-(2-Piperidyl)-3,6-6/s(Trifluoromethyl)-9-Phen-anthrenemethanol... 

Diethyl (3/ , 4/ , 5/ )-2-Benzyl-S-(trifluoromethyl)isoxa/olidinc-3,4-dicarboxylate (6) Typical Procedure ... 

I-Ben/.yl-4,4,S-tril1uoro-S-(trifluoromethyl)-4,5-dihydro-I //-1,2,3-triazole (16) Typical Procedure ... 

N ucleophilic substitution of s-trifluoromethylated sulfonates in the presence of a metal fluoride (functioning as a base) proceeds with complete inversion of the configuration.6... 

An efficient synthetic sequence for the preparation of 2,4-b/s(trifluoromethyl)furan was developed by R. Filler and co-workers. " The potassium enolate of ethyl 4,4,4-trifluoroacetate was reacted with 3-bromo-1,1,1-trifluoroacetate in DMSO to afford 2,4-bis (trifluormethyl)-4-hydroxydihydro-3-furoate as a result of O-alkylation. Interestingly, under these conditions usually C-alkylation is preferred. Next, dehydration was performed to give the corresponding 2,4-bis (trifluoromethyl)-3-furoate in good yield. Finally, decarboxylation by heating with quinoline and CUSO4 yielded the target furan in excellent yield. 

This chapter focuses on how fluorinated methionine analogues interact with biological systems. Specifically the compounds L-monofluoromethionine (l-(S)-(monofluoromethyl) homocysteine MFM), L-difluoromethionine (L-(S)-(difluoromethyl)homocysteine DFM), and L-trifluoromethionine (L-(S )-(trifluoromethyl(homocysteine) TFM) will be the subject of this article (Figure 17.1). A discussion of their syntheses and chemical and conformational properties will be presented. This will be followed by a discussion of their incorporation into peptides and proteins and the properties of the resulting fluorinated biomolecules. The 19F NMR spectroscopic characteristics of these biomolecules will be covered along with how these resonances have revealed information on the properties of the difluoro- and trifluoromethyl moiety (and on the proteins as well ). Further elaboration of these amino acids with metalloenzymes completes the survey. 

Soloshonok, V. A., Kukhar, V., Pustovit, Y. and Nazaretian, V. (1992) A new and convenient synthesis of S-trifluoromethyl-containing amino acids. SynLett., 657-658. 

---