Page images
PDF
EPUB

then added, the whole filtered and stirred with 20 c.c. of a 30 per cent. solution of methylamine. In 24 hours crystals separate. More hydrogen sulphide is then passed through the solution until it is no longer turbid; the crystals are collected, washed with water, and dissolved in ether. It crystallises in needles melting at 65°, and is insoluble in water, soluble in dilute mineral acids, alcohol and glacial acetic acid. It distils with steam, boils at about 185°, being at the same time converted into a compound melting at 130-140°. The hydrochloride forms needles readily soluble in water; it melts at 188° with decomposition.

Dimethylthioformaldinium iodide, S.(CH2),NMeI, is formed by treating the compound with methyl iodide. In two to three days the liquid solidifies to a mass of slender, lustrous needles. It melts at 161163°, and dissolves readily in water, sparingly in alcohol. The platinochloride, [S(CH2),NMe]Me,PtCle, is a bright yellow, crystalline substance. The iodide dissolves in hot aqueous potash and separates unchanged on cooling. When boiled with silver oxide, it yields an ammonium base, which, however, could not be isolated.

N. H. M. Chloro-derivatives of Acetals. By O. MAGNAMINI (Gazzetta, 16, 330-333).-Trichloromethylethylacetal, CCI, CH(OMe) OEt, is obtained by heating tetrachlorether with methyl alcohol in sealed tubes. The reaction is as follows: CCI, CHCl·OEt + MeOH = HCI + CCI, CH(OMe).OEt. It is a colourless liquid of camphor-like odour; it boils at 1934; sp. gr. = 1.32.

Trichlorodimethylacetal, CC, CH(CMe), obtained from tetrachlorethyl methyl ether, is a liquid of similar characters. It boils at 183-2'; sp. gr. 1.28.

The tetrachlorethyl methyl ether, CC1, CHC1-OMe, prepared by the action of phosphoric chloride on chloral methylate, is a colourless liquid boiling at 178°; sp. gr. at 0° 184. It does not appear to have been previously isolated. V. H. V.

Diisonitrosoacetone. By H. v. PECHMANN and K. WEHSARG (Ber., 19, 2465—2467).-V. Meyer and Züblin have shown that when acetoacetic acid is treated with nitrous acid, carbonic anhydride is evolved, and isonitrosoacetone formed. The authors find that when, in like manner, acetonedicarboxylic acid is treated with water and sodium nitrite, a rapid evolution of carbonic anhydride takes place, and diisonitrosoacetone, CO (CH⚫NOH)2, is produced. This forms glistening prismatic crystals, melting with decomposition at 143-144°. It is easily soluble in alcohol and ether, sparingly in cold water, chloroform, and benzene. It is very unstable, and detonates when heated. Its aqueous solution when heated decomposes into hydrocyanic acid, carbonic anhydride, and water. Acids cause a similar decomposition, but hydroxylamine is also among the products. It is more stable in alkaline solutions, and forms alkali salts, which crystallise in orange-yellow needles. Its salts, especially the red crystalline silver salt, explode when heated. When warmed with phenol and sulphuric acid, the nitroso-compound gives a red coloration, with ferric chloride a brown. The authors are further investigating the subject.

L. T. T.

Ketines. By L. ECONOMIDES (Ber., 19, 2524-2527).-When a very dilate solution of diethylketine, C10H1N2, is treated with the theoretical amount of potassium permanganate, a ketinedicarboxylic acid is obtained, identical with that prepared by Wleügel by reducing ethyl isonitrosoethylacetate (Abstr., 1882, 949). If the oxidation takes place in a warm solution, other and more unstable acids are formed. When 5 grams of ethyl imidoisonitrosobutyrate are carefally warmed with powdered zinc chloride at 60-70° for a long time, and the product saponified with alcoholic potash, a small quantity of an acid melting at 190-195°, identical with Wleügel's acid (loc. cit.), is formed. The above reactions, together with the fact that the ketineacid does not yield an anhydride, point to the following constitutional formulæ for methylketine and the ketine-dicarboxylic acid :

[blocks in formation]

Pure Butyric Acid. By A. BANNOW (Ber., 19, 2552-2554).Pure butyric acid is best prepared by converting the commercial acid into the ethyl salt, which is then fractionally distilled. The fraction boiling at 120-121° is reconverted into acid. N. H. M.

Derivatives of Tiglic Acid. By P. MELIKOFF (J. Russ. Chem. Soc., 1886, 287-297).-Tiglic (methylcrotonic) acid,

CHMe: CMe COOH,

was prepared either by the saponification of the oil of Roman chamomile (Kopp, Abstr., 1879, 454), or by heating a-methyl-3-hydroxybutyric acid (Rohrbeck, Abstr., 1878, 136). The acid was treated under water with an aqueous solution of hypochlorous acid, the product of the reaction extracted with ether, and the solvent distilled off. The residue, after remaining for some time over sulphuric acid, solidified to a crystalline mass, which was found to consist of two isomeric chlorhydroxyvaleric acids, C,H,CIO,. A concentrated aqueous solution of this mixture was neutralised with zinc carbonate: a crystalline zinc salt was precipitated, and the mother-liquor on being evaporated left another salt in the form of an amorphous humoïd substance. The two acids obtained by decomposing these salts with sulphuric acid are both easily soluble in water, alcohol and ether; the one forming a crystalline sparingly soluble zinc salt, melts at 75°, and crystallises from ether in thin prisms; the other isomeride melts at 111.5°, and is obtained from its ethereal solution in the form of large, translucent prisms.

When a mixture of these acids, or each of them separately, is treated with alcoholic potash, the potassium salt of an anhydro-acid, CHMe >CMe⚫COOH, is formed. The free acid forms silky, erystalline needles having the odour of butyric acid, easily soluble in water, alcohol, and ether, melting at 62°. The energy with which it enters into direct combination is in the main the same as that shown by B-methylglycidic acid: a-methylglycidic acid in this respect exhibiting

much greater energy. This circumstance, established by experiments on the hydration of the potassium salt by heating with water, is in accordance with the results obtained by the author in a former work on glycidic and a- and ẞ-methylglycidic acids (Abstr., 1885, 650). The energy of direct combination is diminished with increasing molecular weight in acids of analogous constitution; at the same time among isomeric acids the greatest energy is exhibited by the one containing tertiarily united carbon in its molecule. a-p-Dimethylglycidic acid contains one CH2-group more than a- and B-methylglycidic acids, but, on the other hand, one of its carbon-atoms combined with oxygen is in tertiary union.

By the action of hydrochloric acid on a-B-dimethylglycidic acid, a-methyl-B-chlor-a-hydroxybutyric acid, OH CHMe CMeCI-COOH, is formed; it melts at 75°, and is identical with one of the chlorhydroxyvaleric acids above described, the other isomeride being therefore a-methyl-a-chloro-B-hydroxybutyric acid, CHMeCl CMe(OH) COOH. An aqueous solution of a-B-dimethylglycidic acid, when heated during 8-10 hours at 99°, is converted into a-B-dimethylglycidic acid, OH CHMe CMe(OH) COOH, melting at 107°, readily dissolving in water, alcohol, and ether. A. T.

Constitution of Chlorhydroxybutyric and Dichlorobutyric Acid. By P. MELIKOFF (J. Russ. Chem. Soc., 1886, 227-303).Chlorhydroxybutyric acid (formed by the combination of crotonic with hypochlorous acid, Abstr., 1884, 1301, and 1885, 650), when heated with concentrated sulphuric acid, yields monochlorocrotonic acid, crystallising in long, thin prisms, melting at 98°, sparingly soluble in cold, more readily in hot water, easily soluble in alcohol and ether. This acid yields normal crotonic acid (m. p. 72°) on reduction by zinc and sulphuric acid. The chlorocrotonic acid above mentioned is an a-chlorinated product, the isomeric B-derivative being obtained, amongst other methods, by the action of phosphorus pentachloride on ethyl acetoacetate; hence, the chlorhydroxybutyric acid in question must be a-chloro-B-hydroxybutyric acid.

This acid was heated with hydrochloric acid, and a-B-dichlorobutyric acid was obtained; it crystallises in long prisms and melts at 69°. An alcoholic solution of the latter compound, when treated with alcoholic potash, gives a-monochlorocrotonic acid. a-B-Dichlorobatyric acid is formed in like manner when a-monochlorocrotonic acid is heated with hydrochloric acid.

A. T.

Hydroxystearic Acids of Different Origin. By A. C. and M. SAYTZEFF (J. Russ. Chem. Soc., 1886, 328-348).-A hydroxystearic acid was prepared by one of the authors some time ago in his work on the oxidation of oleic acid (Abstr., 1886, 140). Another acid of this composition was discovered by Frémy (Annalen, 19, 296; 20, 50; 33, 10), who obtained it by the action of concentrated sulphuric acid on oleic acid, and described it under the name of hydromargaritic acid. Although the main points of the reaction had been satisfactorily explained by Frémy's work, yet subsequent work on this question has mostly led to unsatisfactory results. Sabaneieff

(Abstr., 1886, 442) has at last succeeded in throwing some new light on the processes involved, but the authors do not in all cases obtain results in agreement with his.

Oleic acid was obtained by the saponification of oil of almonds, and purified in the ordinary way by conversion into its lead salt. The action of sulphuric acid was regulated in such a manner as to prevent the temperature rising above 35°. The mixture was then allowed to remain 20 hours at a temperature below 0°, and decomposed by water. In order to increase the yield of hydroxystearic acid, the fatty layer, separated by the action of water and solidifying at the ordinary temperature to a crystalline mass, was treated with alcoholic potash, whereby the anhydrides of this acid are decomposed. The saponified product was then converted into the acid by boiling with sulphuric acid. When the products of the action of sulphuric acid on oleic acid are left for some time even at low temperatures, the quantity of hydroxystearic acid is diminished, whilst the quantity of its anhydrides increases. Hydroxystearic acid was extracted from the above-mentioned crystalline mass by repeated recrystallisation from ether and alcohol. So obtained, hydroxystearic acid,

CH3(CH2) 13 CH2•CH(OH)·CH2COOH,

melts at 83-85°, and resolidifies at 68-65°. At 20° alcohol (99° Tr.) dissolves 8.78 per cent., ether 2.3 per cent. of the acid. Hydroxystearic acid does not absorb bromine. The free acid and the hydroxystearates of sodium, calcium, barium, copper, zinc, and silver, were analysed, and the formula of the acid shown to be C1H6O3.

With hydriodic acid, hydroxystearic acid yields iodostearic acid. CH, (CH2) 13 CH, CHI-CH2COOH; the latter can be converted into ordinary stearic acid by reducing its alcoholic solution with zinc and hydrochloric acid.

When hydroxystearic acid is heated at 100° in sealed tubes with fuming hydrochloric acid, a syrupy liquid is formed, soluble in ether, insoluble in alcohol and water, and having the composition of oleic acid. It does not show acid properties, nor give additive products with bromine or iodine (in Hubl's solution); it is therefore considered to be a complete anhydride of hydroxystearic acid,

COOCH

<CHO>CO,

formed by elimination of 2 mols. of water from 2 mols. of the acid (analogous to glycolide or lactide). The anhydride is decomposed into hydroxystearic acid by treatment with alcoholic potash at temperatures above 150°. Heated with dilute sulphuric acid (in sealed tubes at 100°), hydroxystearic acid yields the same anhydride, but when concentrated sulphuric acid is used at ordinary temperature, two other products of non-saturated character are formed, one combining with 17 per cent., the other with 33 per cent., of iodine, when heated with it on the water-bath. These substances bear a great resemblance to Frémy's metoleic acid, and will be further investigated.

It was shown that the hydroxystearic acid prepared by the action

of moist silver oxide on iodostearic acid was identical with that described above.

Finally, the authors have studied the action of alcoholic potash on iodostearic acid. After heating the mixture in a reflux apparatus, and expelling the alcohol by distillation, the product of the reaction was decomposed by sulphuric acid. An acid was obtained, solidifying at ordinary temperatures to a crystalline mass, and consequently not identical with oleic acid. It was purified by converting it into the sodium salt, recrystallising this salt from alcohol, precipitating with zinc sulphate, recrystallising from boiling alcohol, and decomposing the zinc salt by sulphuric acid. Thus purified, the substance crys tallises from ether in translucent, rhombic tables, easily soluble in alcohol, sparingly in ether, and melts at 40-45°. The composition of this acid was found to be the same as that of oleic and elaidic acids. It is a non-saturated compound, taking up two atoms of bromine or iodine. When oxidised by potassium permanganate in alkaline solution, it yields dihydroxystearic acid, melting at 78°. The authors intend to continue the investigation of this solid oleic acid. Another acid, melting at 20-25°, simultaneously formed by the action of potash on iodostearic acid, was found to be a mixture of ordinary and solid oleic acids. The constitution of solid oleic acid is CH, (CH) 13 CHCH: CH COOH, ordinary oleic acid being represented by CH (CH2) 13°CH: CH·CH, COOй. A. T.

>0,

Action of Trimethylene Bromide on Ethyl Acetoacetate, Benzoylacetate, and Acetonedicarboxylate. By W. H. PERKIN, Jun. (Ber., 19, 2557-2561; comp. Abstr., 1886, 689).-When the acid C,H10O3 (from trimethylene bromide and ethyl sodacetoacetate) is boiled with water, carbonic anhydride is evolved, and Lipp's acetobutyl alcohol (Abstr., 1886, 218) is formed. When the acid is CH: CHMe. distilled, the anhydride of acetobutyl alcohol, CH, CH, CH2-is obtained; it is a mobile oil. The same compound is also formed when acetobutyl is heated. Strong hydrobromic acid dissolves the ethyl salt C,HO, and decomposes it into bromobutyl methyl ketone (Lipp, loc. cit.) and carbonic anhydride. Benzoyltetramethylenecarboxylic acid is decomposed by hydrobromic acid in a similar manner, with formation of the compound COPh-CH2 CH2·CH2 CH2Br; this crystallises in plates melting at 61°. The instability towards hydrobromic acid of the products obtained by the action of trimethylene bromide on ethyl acetoacetate and benzoylacetate respectively, distinguishes them sharply from tetramethylenedicarboxylic

acid.

Trimethylene bromide acts on the sodium compound

CO(CHNa COOEt)2

2

(from ethyl acetonedicarboxylate and sodium ethoxide), yielding the

compound COOEt·CH←C(CH2COOEt)>0. The latter is a colour

CH-CH2-CH,

less oil boiling at 238-240 (under 150 mm. pressure). The monethyl salt melts at 114; the free acid at 185-190° with decom

« PreviousContinue »