The picrate consists of felted needles, melting-point 198°. Phospho-molybdic acid gives a precipitate crystallising in plates; potassium bismuth iodide gives dark coloured needles.
It produces in animals violent convulsions and muscular tremors; but the substance has hitherto been obtained in too small a quantity to be certain as to its identification and properties.
§ 663. Neuridine, C5H14N2.—Neuridine is a diamine, and is apparently the most common basic product of putrefaction; it has been obtained from the putrefaction of gelatin, of horseflesh, of fish, and from the yelk of eggs. It is usually accompanied by choline, from which it can be separated by converting the bases into hydrochlorides, choline hydrochloride being soluble in absolute alcohol, neuridine scarcely so. Brieger isolated neuridine from putrid flesh by precipitating the watery extract with mercuric chloride. He decomposed the mercury precipitate with SH2, and, after having got rid of the sulphide of mercury by filtration, he concentrated the liquid to a small bulk, when a substance separated in crystals similar in form to urea; this was purified by recrystallisation from absolute alcohol, and converted into the platinum salt.
Another method which may be used for the separation and purification of neuridine is to dissolve it in alcohol and precipitate with an alcoholic solution of picric acid; the picrate may be decomposed by treatment with dilute mineral acid, and the picric acid removed by shaking with ether.
The free base has a strong seminal odour. It is gelatinous, and has not been crystallised. It is insoluble in ether and in absolute alcohol, and not readily soluble in amyl alcohol. It gives white precipitates with mercuric chloride, neutral and basic lead acetates. It does not give Hofmann’s isonitrile reaction. When distilled with a fixed alkali, it yields di- and trimethylamine.
The hydrochloride, C5H14N22HCl, crystallises in long needles, which are insoluble in absolute alcohol, ether, benzol, chloroform, petroleum ether, and amyl alcohol; but the hydrochloride is very soluble in water and in dilute alcohol.
The hydrochloride gives no precipitate with mercuric chloride, potass-mercuric iodide, potass-cadmium iodide, iodine and iodide of potassium, tannic acid, ferricyanide of potassium, ferric chloride, and it does not give any colour with Fröhde’s reagent.
On the other hand, phosphotungstic acid, phospho-molybdic acid, picric acid, potass-bismuth iodide, platinum chloride, and gold chloride all give precipitates.
Neuridine hydrochloride is capable of sublimation, and at the same time it is decomposed, for the sublimed needles show red or blue colours.
Neuridine platinochloride, C5H14N22HCl.PtCl4, yields 38·14 per cent. of platinum; it crystallises in flat needles, soluble in water, from which it is precipitated on the addition of alcohol.