Fluoroacetamide standard

For standardizing the estimation of fluorine in fluoroacetates, a compound of undisputed purity containing the CH2F group is re- 

A pure specimen was prepared as follows. Methyl iluoroacetate (39 g.) was shaken with 30 ml. of ammonia solution (sp. gr. = 0 89). Heat was evolved, and on standing overnight the first crop of almost pure crystals was deposited. These were filtered off and dried (yield, 16 g.). By concentrating the filtrate in vacuo a second crop of crystals was obtained (yield, 5 g.). The two crops were united and Could be recrystallized from chloroform (fine needles) or acetone (prisms). We used dry chloroform and each recrystallization gave about 75 per cent yield. After recrystallizing three times, the final yield of pure substance was 8 7 g., m.p. 108°. The amide can also be purified by sublimation. 

The determination of nitrogen in the pure product was performed by the usual method of slow distillation with excess of dilute sodium hydroxide solution, the evolved ammonia being collected, during 4 hr. distillation, in standard acid, and determined by titration as usual, with methyl orange as indicator. The yield of ammonia corresponded to 18-19 per cent of nitrogen in this sample. Calculated for FGHjCONH, N = 18-18 per cent. The standard fiuoroacetamide was therefore 100 per cent pure. 

Specimen determination of fluorine in methyl fluoroacetate by fvMon with sodium 

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C, which decomposes when heated above the melting point. Its solubility at 25°C in g/100 g solvent is water. 111 methanol, 5 ethanol, 1.4 acetone, 0.04 and carbon tetrachloride, 0.004. Because its carbon—fluorine bond is unreactive under most conditions, this salt can be converted by standard procedures to typical carboxylic acid derivatives such as fluoroacetyl esters (11,12), fluoroacetyl chloride [359-06-8] (13), fluoroacetamide (14), or fluoroacetonitrile [503-20-8] (14). 

Standardization, of the sodium peroxide bomb method with pure fluoroacetamide... 

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