Organic chemistry

1889 Journal of the Chemical Society Abstracts  
Organic C h e m i s t r y . Soluble Prussian Blue. By C. E. GUIGNET (Compt. rend., 108, 178-181) .-Ordinary soluble prussian blue is a compound of prussiari blue with potassium ferrocyanide. It is easily obtained by gradually adding to a boiling solution of 110 grams of potassium ferricyanide R hot solution of 70 parts of crystallised ferrous sulphate. The mixture is boiled for two hours, filtered, and the precipitate washed until the washings become dark blue. It is then dried at loo", and has
more » ... a fine deep-blue tint, and is very soluble in water. Admixed potassium ferrocyanide can be removed by washing with alcohol of 40 per cent. The compound is precipitated from its solution by sodium sulphate, sodium chloride, &c., but when the salts are removed by washing it redissolves. With salts of lead, zinc, and other metals, it yields, as Wyrouboff observed, a series of well-defined blue compounds. Colloidal prussian blue was obtained by Graham by dialysis. Pure soluble prussian blue is obtained by suspending purified prussian blue in a saturated solution ot oxalic acid, filtering, and allowing the mixture to remain for two mouths. Prussian blue is completely precipitated, and the liquid is quite colourless. After thorough washing with dilute alcohol, the precipitate is readily soluble in pure water. The same result is obtained in a very short time by precipitating the oxalic acid solution with strong alcohol o r by a concentrated solution of sodium sulphate, and washing the precipitate with dilute alcohol. Ammonium oxalate or tartrate can be used instead of oxalic acid. 476 ABSTRAUTS OF DHEMICAL PAPERS, alcohol, the solution yields a precipitate of ordinary prussian blue, which retains snlphuric acid even after prolonged washing with dilute alcohol. Ethyl hydrogen sulphate does not dissolve prussian blue, and hence the phenomena just described cannot be atkributed to the formation of this compound. C. €€. B. Relative Stability of the Alkyl Bromides. By I?. LENGFELD (Amer. Chem. J., 71, 40--66).-The stability of alky.1 bromides when in solution with various reagents has been determined. With sodium hydroxide, potassium hydroxide, and ammonia, the relative stability is (in order of increasing stability), ethyl, propyl, butyl, isoamyl, isobutyl, isopropyl. With nitric and sulphuric acids, the order of increasing stability is isopropyl, ethyl, propyl and butyl (about equal), isoamyl, isobuty I, eth lene. &ith argentic nitrate and argentic nitrate and nitric acid, the order of increasing stability is isopropyl, ethyl, propyl, isoamyl, isobutj 1, ethylene. Experiments carried out on the influence of light on the stability of alkyl bromides in contact with sodium hydroxide showed that it was without influence on the result. With dilute sodium hydroxide, n/4Q and less, the velocity of changes is inversely as the concentration. The action of sodium hydroxide on the bromides dissolved in methyl alcohol is slower than in propyl alcohol, and slower in propyl than in ethyl alcohol. In the case of excess of one reagent over another, similar effects are produced by similar excess of ether reagcnt. J. VV. 3;. Analyses of Pure Sherry. By E. BORGMANN and W. BRESENIUS (Zeit. anal. Chern., 28, 71-77).-The authors, having obtained 18 samples of genuine sherry of various qualities, have aualysed them by recognised methods and give the results in a table. The chief feature worthy of notice is the high percentage of sulphates. The universal practice of plastering the must for the manufacture of sherry renders it necessary to adopt for that wine an admissible maximum different from that allowed in unplastered wines. The sulphates found (calcnlated as potassium sulphake) ranged from 2.5-8.8 grams per litre. The superior brands (with two exceptions) contained more than 4 grams, and the inferior (with one exception) less than 3 grams per litre. The niaximum limit of 3 grams proposed by the German I mperial Commission wouId exclude the finer wines of this class. Plastering increases the proportion of potassium in the wine, but not that of calcium. Phosphoric acid, chlorine, and magnesinm appear to rise with increasing sulphates. I n most of the samples, a deposition of tartar occurred on keeping. This fact. is of interest in connection with the dictum of Blitz, that in judging of a, wine containing much snlphates, it is necessary to consider whether at tshe same time a suffi-cie& amount of hydrogen potasbium tartrate is present. M. J. S. 106 --110 ; compare Abstr., 1888, 1264).-T1*ihydroxyisobutyric acid, OHC(CH2.0H)a*COOH, is obtained when glyceroge (250 grams) is mixed with anhydrous hydrocyanic acid (30 grams) and allowed to remain for 12 hours at, 50" and a second 12 hours at 60" in a wellclosed vessel. After the removal of the excess of hydrocyanic acid, the product is concentrated fo 150 c.c., saturated with hydrogen chloride in a freezing mixture, and allowed t>o remain two days at the ordinary temperature. It crystallises from alcohol in slender, colourless prisms, melts at 116", and is readily soluble in water, sparingly soluble in alcohol, and almost insoluble in ether, benzene, and chloroform. The calcizcm salt, with 4 mols. H20, crystallises in slender, matted needles ; the lend mlt, with 1 mol. HzO, crystallises in slender, colourless prisms ; the normal burizcrn salt could not be crystallised ; the basic barium salt, C,H,O,Ba, is precipitated from a hot solution of the acid in slender needles ; the strorttiurn salt crgstlallises in slender needles; the sodium salt in prisms. On reduction with hydriodie acid and amorphous phosphorus in a reflux apparatus, trihydroxyisobutyric acid is converted into a mixture of acids containing iodine, and these, by further reduction with zinc-dust and dilute sulphuric acid, yield isobntyric acid. Diiodoisobutyric acid, C4H60212, can be extracted by ether from the product obtained on redwing trihydroxyisobutyric acid with hydriodic acid and amorphous phosphorus. It crystallises from water in long, colourless needles, melts at 127", and is very readily soluble in alcohol and ether. In addition to trihydroxyisobutyric acid, a, small yield of erythroglucic acid is also obtained on treating glycerose with concentrated Extraction of Sorbite. Rp C. VINCENT and DELACRANAL (COW@. rend., 108, 147--148).--The fermeuted juice of Sorbus auczipuria is concentrated in a vacuum to one-third of its volume, and 10 grams are heated with excess of sulphuric acid, evaporated to dryness, the residue calcined, and the combined sulphuric acid estimated. The amount of sulphuric acid required to convert into sulphates all the bases i n the juice is calculated from this result, and ibis quantity of acid is added to the concentrated juice, which is then diluted with its own volume of water and twice the volnme of alcohol. The calcium and potassium, which interfere with the crystallisation of sorbite, are thus almost compietely precipitated in the form of sulphates. The liquid is filtered, the alcohol distilled off, and the residue exactly neutralised with barium hydroxide, evaporated t c a, s,yrup, and extracted with boiling alcohol of 95", which dissolves almost pure sorbite, and leaves in combination with the barium the viscous acid substances which usually interfere greatly with crystallisation. When the alcoholic solution is concentrated, it leaves a syrup which after a few d a p deposits a large quantity of sorbite in long needles. Sorbite may be estimated in the form of dibenzoic acetal (followinq Abstract) in the following manner. The juice is concentrated in a hydrocyanic acid. w. P. w. Pigments of the Urine. By C. A. MACMTTNN ( J . Phpiol., 10, 71-121). -A full account, with plates of absorption-spectra and measurement of bands, of experiments of which an account has already appeared (Abstr., 1888, 61 4).
doi:10.1039/ca8895600475 fatcat:dmlot56ibbc3hiwlr6weoutshi