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But the recent investigations of the author, showing that the acid takes up at first four atoms of bromine to form a tetrabromo-acid, which is reconverted by hydrogenation into the original acid, and that this acid by the further addition of four atoms of bromine gives an additive product, as also yields a pentabromo-derivative, indicate that pyrotritartaric acid is analogous to and probably a derivative of pyromucic acid. This view is confirmed by its synthesis from ethyl acetonylacetoacetate and its reactions with phenylhydrazine and hydroxylamine; pyrotritartaric acid is then probably a dimethylfurfuranecarboxylic O--CMe >C.COOH.

acid, CMe:CH

V. H. V.

Derivatives of Pyrotritartaric Acid. By F. DIETRICH and C. PAAL (Ber., 20, 1077–1080).-Hitherto the derivatives of pyrotritartaric acid, with the exception of the salts, have not been investigated, owing to its indifference towards some reagents, and its complete decomposition by others. By bromination in chloroform solution, a tetrabromopyrotritartaric acid, CH,BrO COOH, is formed, which crystallises in well-formed prisms melting at 161°, soluble in alcohol and ether, insoluble in water and petroleum; its metallic and ethereal salts are unstable. When treated with bromine, it takes up four more atoms of bromine to yield tetrabromopyrotritartaric acid tetrabromide, C&H Br2O COOH, which crystallises in short prisms melting at 168-170°; the salts of this acid are unstable, and it is completely decomposed by alkalis. On treating the tetrabromo-derivative with excess of bromine in sealed tubes, a pentabrominated acid, C&H2Br2O COOH, is formed. This crystallises in elongated rhombohedra, and melts at 197°.

Wislicenus and Stadnicki found that when pyrotritartaric acid is treated with phosphoric chloride it yields an acid chloride, decomposed by water to re-form the acid; but if the reaction is conducted at a higher temperature, a dichloro-compound is formed; the latter is a colourless, heavy oil of disagreeable odour, converted by exposure to damp air into pyrotartaric acid and a resin.

During the distillation of carbopyrotritartaric acid, a dimethylfurfuran, identical with that obtained from acetonylacetone, together with pyrotritartaric acid and uvinone, are formed. This last substance, CH2O, crystallises in tufts of needles, melting at 247.5°; with bromine, it yields an octabromo-derivative, CH,Br.O, crystallising in pyramidal prisms, sparingly soluble in most menstrua; when heated, it carbonises with evolution of bromine and hydrobromic acid. V. H. V.

B-Bromofurfuran. By F. CANZONERI and V. OLIVERI (Gazzetta, 17, 42-44).—Two bromo-derivatives of furfuran are indicated by theory, namely, one in which the bromine displaces a hydrogen-atom in either of the CH groupings attached to the oxygen-atoms, and the second in which a hydrogen-atom is displaced in one of the CH groupings not attached to the oxygen. Both these substances have been obtained by the decomposition of the bromopyromucic acids. In order to prepare ẞ-bromofurfuran, the corresponding bromopyromucic acid

is first purified from the dibromo-acid by means of its ethyl salt, which is saponified, and the acid obtained is then distilled with an equal weight of lime. B-Bromofurfuran, thus produced, is a colourless, transparent liquid, boiling at 103°, heavier than and insoluble in V. H. V.

water.

Synthesis of Hemellithene. By O. JACOBSEN and W. Deike (Ber., 20, 903—904).-Metaxylenesulphonic acid [Me: SO,H: Me = 1 2 3] is obtained by sulphonating dibromometaxylene

:

[Me: Me: Br: Br 1: 3:4; 6]

with chlorosulphonic acid, converting the sulphochloride formed into the sodium salt of the acid by means of alcoholic soda, and removing the bromine with zinc-dust and ammonia. When a hot solution of the sodium salt is treated with bromine dissolved in hydrochloric acid, the corresponding bromometaxylene is obtained, and this is converted. into hemellithene by the action of sodium and methyl iodide in ethereal solution.

Bromometaxylene boils at about 206°, and does not solidify at -10°, W. P. W. By F. MAYER (Ber., 20,

Reduction of Trinitro-y-cumene. 966-973).—The constitution of the acid, C,H12N2SO, (this vol., p. 36), obtained when trinitro-y-cumene is reduced with hydrogen sulphide, cannot be ascertained from an examination of its salts, which are unsatisfactory compounds, nor is it possible to characterise it either as a carboxylic acid or a mercaptan. If, however, it is heated with concentrated sulphuric acid at 140-150°, a considerable quantity of the sulphate of Fittig's nitro-y-cumidine (Annalen, 151, 157), is obtained, and inasmuch as on heating either with concentrated hydrochloric acid or with water at 180°, it yields the same sulphate and also sulphuric acid, it follows that the compound must be regarded either as a nitro-y-cumidinesulphonic acid or as a nitro-y-cumidinesulphaminic acid, NO, CHMe, NH SO,H. The synthetical formation of the compound by heating nitro-y-cumidine sulphate with chlorosulphonic acid at 165° for four hours does not distinguish between the formulæ, and no evidence has been obtained to show which of the two is correct.

Acetylnitro-y-cumidinesulphonic acid, C,HN2SO,Ac, melts at about 230° with decomposition, and is readily soluble in water and alcohol, sparingly soluble in ether.

:

The constitution of nitro-y-cumidine [Me: NO, Me: Me: NH2 = 1:23:46] and of nitro-y-cumidinesulphonic acid follows from the fact that both compounds, on reduction with tin and hydrochloric acid, yield meta-y-cumylenediamine [Me: NH, Me: Me: NH2 = 1: 2: 3:4: 6], whilst the former, by elimination of the amido-group and subsequent reduction with stannous chloride, is converted into third y-cumidine which must have the formula [Me: NH,: Me: Me = 1:23:4].

Meta-y-cumylenediamine crystallises in long, hard needles, melts at 840, and dissolves readily in benzene. Ferric chloride gives to its solution an intense dark-red colour. When treated with diazo-com

pounds, chrysoïdines are obtained, whilst with nitrosodimethylaniline hydrochloride it yields a dye analogous to Witt's toluylene-red.

-Cumidine boils at 236°, and does not solidify at -15°. Its acetylderivative, C,H,NAc, melts at 186°. This cumidine is probably identical with that obtained by Nölting and Forel (Abstr., 1886, 58). The corresponding nitrotrimethylbenzene melts at 30°.

W. P. W.

By

Action of Sulphuric Acid on Pentamethylbenzene. O. JACOBSEN (Ber. 20, 896—902).-Pentamethylbenzene, obtained by the action of methyl chloride on mesitylene or pseudocumene in the presence of aluminium chloride, can readily be separated from the accompanying hexamethylbenzene by fractional crystallisation from alcohol; its purification from small quantities of durene and possibly of isodurene is, however, more difficult, and is best effected by sulphonating the impure hydrocarbon with chlorosulphonic acid Pentamethylbenzene sulphone and sulphochloride are formed, and the latter is converted into the sodium sulphonate, separated from any durene-sulphonate by crystallisation, converted into the sulphonamide, and together with the sulphone saponified at 170° with concentrated hydrochloric acid. The sodium, potassium, barium, calcium, silver, and copper salts of pentamethylbenzenesulphonic acid are described; they are crystalline, anhydrous, and sparingly soluble in water; the chloride, C.Me, SO2CI, crystallises from ether in large, flat prisms, and melts at 82°; the amide forms large, flat prisms, showing a vitreous lustre, melts at 186°, is sparingly soluble in cold alcohol, and when oxidised with potassium permanganate yields a sulphonamic acid melting at about 265°. sulphone crystallises in very long, slender, colourless needles, melts at 985°, is readily soluble in alcohol, and on distillation yields pentamethylbenzene.

The

When sodium pentamethylbenzenesulphonate is shaken with concentrated sulphuric acid and light petroleum, hydrolysis occurs and the pure hydrocarbon is obtained on evaporation of the latter. The sulphonic acid cannot be prepared by the action of concentrated sulphuric acid, inasmuch as pentamethylbenzene when repeatedly shaken with 3 to 4 times its weight of the acid during 36 to 48 hours, and then treated with ice, yields prehnitenesulphonic acid and a solid hydrocarbon, which is found to be hexamethylbenzene and not an octamethylanthracene (Abstr., 1886, 694). The action of sulphuric acid on durene (loc. cit.) may, therefore, be regarded as resulting in the formation of pseudocumene and pentamethylbenzene, the latter in the presence of the acid undergoing further change into prehnitine and hexamethylbenzene. W. P. W.

Resorcinol-derivatives. By W. WILL and W. PUKALL (Ber., 20, 1119-1136).-Esculetin has been recognised as a dihydroxyderivative of coumarin, but the trihydroxybenzene, from which it is derived, has as yet not been isolated. The starting point of experiments made in this direction was the preparation of benzeneazoresorcinol, CH3(OH)2°N2Ph [OH: OH: N2Ph=1:3:4], from resorcinol, by means of the diazo-reaction. This substance, previously

described by other investigators, yields with ethyl iodide in presence of potash a mono- and a di-ethoxy-derivative. The former,

OH C&H (OEt) N2Ph,

crystallises in prisms resembling alizarin; it melts at 87°, is readily soluble in alcohol, insoluble in water; the latter crystallises in yellowish-red needles melting at 70-5°, soluble in alcohol and ether. On hydrogenation with tin and hydrochloric acid, the stannochlorides of aniline and amidodiethoxyresorcinol are produced. The hydrochloride of the latter exists in two modifications, namely, as glistening needles or a grey, crystalline powder, both of which melt at 198°, and are converted the one into the other according to the conditions of crystallisation. The free base, CH3(OEt) NH2, crystallises in broad needles melting at 32°; its salts are very soluble and readily oxidised; the dibromo-derivative crystallises in needles melting at 112°; the acetyl- and the benzoyl-derivatives melt at 120-5° and 113.5° respectively. When amidodiethoxyresorcinol is oxidised either by exposure to air or more readily by a ferric salt, a deep blue liquid is obtained, from which a violet-brown precipitate separates, and may be purified by sublimation. This compound, CHINO5, is formed thus: 2CH(OEt),NH2 + O2 = C18H2NO + NH, + EtOH; it crystallises in steel-blue needles melting at 170°, and is soluble in alcohol, insoluble in ether. It is probably a derivative of quinone, of the formula OEt C.H2O2·NH·C2H2(OEt), [O: NHC,H,(OEt),: OEt: 0 = 1:2:3:4).

Amidodiethoxyresorcinol, on oxidation with chromic acid, yields an ethoxyquinone, CH2O2OEt [O: OEt: 01:3: 4], crystallising in yellow needles melting at 117°; it dissolves in water, and its solution gives on addition of a trace of amidoethoxyresorcinol a blue coloration from formation of the above intermediate condensation-product. Ethoxyquinol, CH(OH)2 OEt, obtained by reduction of the quinone with sulphurous acid, crystallises in colourless prisms melting at 112.5°, and is soluble in water, alcohol, and ether. The triethoxyderivative, CH,(OEt), crystallises in glistening needles melting at 34°; from the corresponding phenol, æsculetin is derived.

Ethylamidoresorcinol, OH CH(OEt) NH2 [OH: OEt: NH2 = 1:3:4], prepared in a manner similar to the above diethoxy-compound, forms colourless needles melting at 148°, soluble in water and alcohol. On oxidation with chromic acid, it seems to yield a quinone.

V. H. V.

Resorcinol-derivatives. By W. PUKALL (Ber., 20, 1136—1152). -Diazodiethylresorcinol chloride, CH,(OEt), N,CI, obtained under particular conditions from amidodiethylresorcinol sulphate, is an unstable, crystalline substance, soluble in water with greenish-yellow coloration. By boiling water, as also by alkalis, it is readily converted into a diethylresorcinol, although the reaction is complicated by subsidiary changes, which lead probably to the formation of diresorcinolderivatives. These substances were, therefore, separately examined. Tetrethyldiresorcinol, C12H(OEt), prepared from diresorcinol and ethyl iodide in presence of alkali, crystallises in large, colourless

leaflets melting at 100°, soluble in ether, insoluble in water, acids, and alkalis.

2

Diethylresorcinolparazoresorcinol, CH(OEt), N2 CH(OH)2, prepared from diazodiethoxyresorcinol and resorcinol, forms glistening green crystals melting at 193.5°, insoluble in water and dilute acids, readily soluble in alcohol.

Orthophenylazoethylresorcinol, PhN2 CH(OH) OEt, obtained together with the para-derivative, in small quantities by the ethylation of crude phenylazoresorcinol, crystallises in carmine-red needles, melts at 150°, is readily soluble in alcohol and ether, and in contradistinction to the para-derivative, is soluble in alkalis. By further ethylation, it is converted into the diethyl-derivative, PhN, CH(OEt), which forms glistening tabular crystals melting at 90°, insoluble in water, acids, and alkalis. On reduction with tin and hydrochloric acid, it is converted into orthamidodiethylresorcinol hydrochloride,

C&H (OEt)2NH2, HCI,

which crystallises in colourless needles; the free base crystallises in leaflets melting at 124°, soluble in alcohol, insoluble in water. On oxidation, it yields a compound, C18H20N2O3, the constitution of which was not further investigated; it crystallises in brown-red needles. melting at 207°. Attention is drawn to the formation of an ortho-, together with a para,- derivative in the diazo-reaction. Liebermann considers that the production of the ortho-derivative in this reaction is more common than has been hitherto suspected, but the quantities formed are insufficient for their separation. Diethylresorcinolorthazoresorcinol,

pre

CH(OEt),2N2CH3(OH)2, pared from diazodiethoxyresorcinol and an aqueous solution of resorcinol, is a reddish-yellow, crystalline precipitate, melting at 182.5°, soluble in alcohol and ether, insoluble in water.

Experiments made with a view of obtaining the corresponding phenol led to no satisfactory results. V. H. V.

Triphenylthiammeline and a Third Triphenylammeline. By B. RATHKE (Ber., 20, 1065-1074).-Triphenylthiammeline,

[blocks in formation]

is obtained, together with other products, by heating triphenylthiodicyandiamine; it crystallises in leaflets melting at 238, and is sparingly soluble in alcohol, moderately soluble in chloroform. It functions both as an acid and a base, forming with mineral acids crystalline salts, such as the hydrochloride and sulphate, and also dissolving in alkalis to form crystalline metallic derivatives, decomposed by carbonic anhydride. When heated with ethyl bromide and alcohol, triphenylthiammeline yields the hydrobromide of the corresponding mercaptide, C,N,HPh3 SEt, HBr. This crystallises in colourless, strongly refractive prisms, of neutral reaction, and is converted into triphenylammeline when boiled with alcohol. This substance, also obtainable from tetraphenylmelamine, crystallises in

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