Fluorine-containing ammonium salts

It is well known that the amino and acetamido group and quaternary ammonium groups often render compounds physiologically active. Particular reference may be made to the work of Haworth and his collaborators on the toxic action associated with quaternary ammonium salts.  

In view of these facts and of the known toxic action of fluoro-acetates it seemed worth while investigating compounds containing both fluorine and the above-mentioned groups. We prepared the flrst of a series of nitrogen compounds in 1943, namely, ethyl jluoroacetamidoacetate, CHjF CO NH CHg COjEt (XH). It was a colourless crystalline solid which, when injected into mice, had a l.d. 50 of 20 mg./kg. The corresponding figure for methyl fluoroacetate is 6 mg. /kg. The symptoms were similar in each case (delayed convulsant action). 

2 Fluoroethyl aminoacetate hydrochloride (XIII) was readily prepared by esterifying glycine with fluoroethanol (F.E.A.) according to the Fischer-Speier method  

Using similar conditions with betaine and F.E.A. none of the expected ester was obtained, the betaine remaining unchanged. The reaction between anhydrous trimethylamine and fluoro-ethyl chloroacetate, however, gave 2 fluoroethyl betaine hydrochloride (XIV) in excellent yield  

The hydrochloride (XIII) had a l.d. 50 of ca. 10 mg./kg. by subcutaneous injection into mice. The corresponding figure for 2-fluoroethyl betaine hydrochloride was 45 mg./kg. Both (XIII) and (XIV) produced fluoroacetate-like symptoms. 

In preparing other compounds containing fluorine and quaternary ammonium groups, advantage was taken of the fact that of 

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Fluorine containing ammonium salts. As amino compounds often have marked physiological action, it seemed worth while to prepare compounds containing both fluorine and a quaternary amino grouping. 

Polyfluorobenzyl alcohols are one class of fluorinated starting materials for medicinal and agricultural usage. Practical electrochemical methods for the product-selective synthesis of polyfluorobenzyl alcohols have been developed [79, 80], 2,3,4,5,6-Pentafluorobenzoic acid is reduced selectively to 2,3,4,5,6-pentafluorobenzyl alcohol at amalgamated lead, zinc and cadmium cathodes in aqueous sulfuric acid solutions, while 2,3,5,6-tetrafluorobenzyl alcohol can also be obtained selectively by using the non-amalgamated cathodes in solutions containing small amounts of a quartemary ammonium salt [79],... 

The study of these fluorine-containing salts was then extended, and we prepared other new compounds in this series, e.g. 2-fluoroethyl glycine hydrochloride and 2-fluoroethyl betaine hydrochloride (that is, carbofluoroethoxy-methyl trimethyl ammonium chloride). The first of these was readily prepared by the Fischer-Speier esterification of glycine with fluoro-ethyl alcohol ... 

In a series of publications on the fluorination of amines and quaternary ammonium salts Rudiger and co-workers have reported their findings on the analyses of the three product containing phases from the reactions, the perfluorinated liquid phase, the gaseous phase, and the so-called HF-phase, which was shown to contain significant quantities of partially fluorinated material, some of which were considered as intermediates in the fluorination process, but also others which remained inert to further reaction [180, 181]. 

DISPOSAL AND STORAGE METHODS dispose of in accordance with federal, state, and local regulations store in a cool, dry area use only with adequate ventilation storage should be in tightly sealed containers containers should be protected from physical damage separate from acids, aluminum, ammonium salts, fluorine, mercury, hydrogen, heat, sparks, and open flame. 

The use of a conventional PFPE is limited by the solvent. However, since the modified PFPEs contain a hydrocarbon moiety and ammonium salt moiety, it is soluble in alcohols, and other conventional fluorinated solvents, which makes its practical use convenient. Fig. 14 shows the consequences for friction of the steaiyl ammonium salt of Z-lube by changing to a thirmer dip-coating. In this case, ethanol, n-hexane-20%wt.ethanol, and a fluorinated solvent were used. It is evident that the frictional properties are independent of the dip>-coating solvent. 

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