Fiuoroacetic acid

Gassman and co-workers developed a synthetic route from anilines to indoles and oxindoles which involves [2.3]-sigmatropic rearrangement of anilinosul-fonium ylides. These can be prepared from Ai-chloroanilines and ot-thiomcthyl-ketones or from an aniline and a chlorosulfonium salt[l]. The latter sequence is preferable for anilines with ER substituents. Rearrangement and cyclizalion occurs on treatment of the anilinosulfonium salts with EtjN. The initial cyclization product is a 3-(methylthio)indole and these can be desulfurized with Raney nickel. Use of 2-(methylthio)acetaldehyde generates 2,3-unsubstituled indoles after desulfurization[2]. Treatment of 3-methylthioindoles with tri-fiuoroacetic acid/thiosalieylie acid is a possible alternative to Raney nickel for desulfurization[3]. 

Homfeldt, C.S., Larson, A.A. (1990). Seizures induced by fiuoroacetic acid and fiuorocitric acid may involve chelation of divalent cations in the spinal cord. Eur. J. Pharmacol. 179 307-13. 

Class B Fluoroacetic acid and salts, e.g. sodium fluoro-acetate, triethyl-lead fiuoroacetate all simple esters of fiuoroacetic acid fluoroacetamide and substituted amides fluoroacetamidine hydro-chloride fiuoroacetyl chloride and fluoride fluoro-ethanol and its simple esters fluoroacetaldehyde. 

Trifluoroacetic acid is a voiatiie and corrosive chemicai. Wear iatex gioves when handiing this chemicai and do not breathe it or aiiow it to come in contact with your skin, if contact occurs, immediateiy fiood the affected area with coid water and then rinse with 5% sodium bicarbonate soiution. Dispense tri-fiuoroacetic acid oniy at a hood. 

R. J. Mead and W. Segal, Austral. J. Biol. Set., 1972, 25, 327 Fluoroacetic Acid Biosynthesis A Proposed Mechanism . It is suggested that fluoride ion attacks a Cg entity linked to pyridoxal phosphate and derived from cysteine, serine, etc., to yield pyridox-amine phosphate-bound fluoropyruvate (1) which equilibrates with pyridoxal phosphate-bound fluoroalanine (2) subsequent hydrolysis, etc., produces fiuoroacetic acid. 

Ethyl, W propyl and isopropyl fluoroacetates were also readily prepared by heating the corresponding esters of chloroacetio acid with potassium fluoride in the rotating autoclave. Their toxicities were similar to that of methyl fiuoroacetate. (It... 

NaH allowed to react with abs. alcohol in ether, after H -evolution has ceased an ethereal soln. of benzaldehyde and ethyl fiuoroacetate added at 18°, stirred continued 7 min., then poured on HCl-ice a-fiuoro-) -hydroxy-/ -phenylpro-pionic acid (Y 24%) and its ethyl ester (Y 57%). E. Elkik and C. Francesch, Bl. 1973, 1277, 1281 cf. Synth. Meth. 8, 842. 

Figure 3 The NMR spectrum of a perfusate (concentrated 20-fold by lyophilization) from an isolated perfused rat liver treated with 5-fluorouracil at a dose of 45 mg per kg b.w. for 3 h. F , fluoride ion FUR, 5-fluorouridine FU, 5-fluorouracil FBAL, a-fluoro- -alanine CFBAL, N-carboxy-a-fluoro-/3-alanine FBAL[R]-gluca, FBAL[R]-glucvS, adducts of a-fluoro- -alanine with a-glucose or glucose FMASAIc, fluoromalonic acid semi-aicohci FAC, fiuoroacetate.

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