cule, corresponds with that undergone by the nitrate:-CH, N2•O•NO2 = C,H,(OH) NO2+ N2. Phenetoil boils at 170°, and when treated with fuming nitric acid yields dinitrophenol (m. p. 86-87°). This is very nearly the melting point of dinitrobenzene (89.9°), and hence the misstatement that benzene is the principal product of the decomposition of diazobenzene with alcohol.

When orthodiazotoluene sulphate is heated with absolute alcohol, the principal product is orthocresyl ethyl ether (30 per cent.); neither toluene nor aldehyde could be detected. With the para-compound, the decomposition is quite different, 18 per cent. of toluene and 11 per cent. of paracresyl ethyl ether being obtained, as well as aldehyde. Metadiazotoluene sulphate and absolute alcohol yield neither aldehyde nor toluene, but metacresyl ethyl ether is formed (55 per cent. reckoned on the metatoluidine employed). The metatoluidine was prepared from paratoluidine by nitrating the acetyl-derivative, eliminating the amido-group, and reducing the metanitrotoluene. In this case, it is to be noticed that the diazo-group is readily displaced by hydrogen, a yield of 68.7 per cent. being obtained.

The authors conclude that the presence of a paraffin residue in the para-position relatively to the diazo-group is favourable to the displacement of the diazo-group by hydrogen. Wroblewski, from a study of the three chlorotoluidines, concludes that in the decomposition of the diazo-compounds by alcohol the normal reaction (production of the hydrocarbon) suffers a change due to the influence of the halogen when it occupies the para-position relatively to some other substituting group. This conclusion is contradicted by the author's experiments. Of the nine recorded cases of mono-substituted amido-benzene compounds that undergo Griess' reaction, eight contain the two groups in the para-position. An examination of the 80 or 90 cases in which two or more groups are present besides the amido-group, and in which the diazo-group is displaceable by hydrogen, also shows that in nearly all cases the amido-group is in the para-position with respect to some other group. H. B.

Diphenylpara-azophenylene. By E. v. BANDROWSKI (Monatsh., 8, 475-483). In a former paper (Abstr., 1886, 1023), the author showed that the product of the oxidation of diphenylamine in alkaline NPh. solution is a diphenylpara-azophenylene, C.H.<P>, a view confirmed by its ready hydrogenation into a leuco-product; the latter seems to be identical with Calm's diphenylparaphenylenediamine. To confirm this view, this substance was prepared according to Calm's directions from quinol and aniline heated with a mixture of zinc and calcium chlorides in a sealed tube at 200-210°. Thus prepared, the melting point of the compound was found to be 132-135°, instead of 152° as assigned to it by Calm. The same melting point was found for the substance CiH1N2, prepared by the author's method; hence there can be no doubt as to the identity of the two compounds in question. This identity was further confirmed by the conversion of the diphenylparaphenylenediamine, prepared by either method, into the oxidation product of diphenylamine, C8H1N2, which was effected

VOL. LIV.

t

either directly by moderate oxidation with hydrogen peroxide, or indirectly by decomposition of the dinitroso-derivative in hot alcoholic solution. This dinitroso-derivative, formed by passing nitrous fumes into a cold alcoholic solution of diphenylparaphenylenediamine, forms yellow, glistening crystals, melting at 120° with decomposition. It gives an intense red coloration with sulphur and nitric acid, and is converted by hydrogenation with zinc-dust and acetic acid, into diphenylpara-azophenylene, and on boiling with alcohol, into diphenylpara-azophenylene and nitric oxide. On bromination in chloroform solution, diphenylpara-azophenylene gives a bromo-derivative,

This forms acicular crystals melting at 243°. It dissolves in nitric acid with production of a dirty-green colour. On dilution a reddish precipitate of a dinitro-derivative is obtained, but this probably consists of two isomeric substances. V. H. V.

Substitution in Azo-compounds. By E. NÖLTING (Ber., 20, 2992-2998).—Amidoazobenzene yields several crystalline compounds when nitrated, none of which, however, are identical with 1 : 4 or 1:3 C&H1(NO2) NN·C2H, NH2. The nitro-group seems to enter the amidated group, since aniline was obtained by the reduction of the compound.

When phenylazodimethylaniline (dimethylamidoazobenzene) is dissolved in concentrated sulphuric acid (66° B.), nitrated in a freezing mixture with a mixture of 50 per cent. nitric acid (1 part) and sulphuric acid (2 parts), and the product poured into water, a nitroderivative, PhN:N·C6H3(NO2) NMe2, is obtained, which crystallises in black needles with a greenish iridescence, and melts at 198°; it is insoluble in water, sparingly soluble in alcohol and ether, readily soluble in benzene. It is a feeble base, and on reduction yields aniline and another base, probably dimethyltriamidobenzene. An isomeric nitro-derivative, NO2 CH, N2 CH, NMe2, is also formed, identical with that prepared by Meldola (Trans., 1884, 107). This crystallises in needles, melts at 225-226°, and is sparingly soluble in alcohol, ether, and benzene. On reduction with ammonium sulphide, it yields amidodimethylamidoazobenzene melting at 186-187°, and with tin and hydrochloric acid it is converted into paraphenylenediamine and dimethylparaphenylenediamine.

2

2

When paratolylazodimethylaniline is nitrated in like manner, it yields a nitro-derivative, C,H,Me N2 C&H2(NO2) NMe2, which crystallises in long, bright red needles, melts at 181°, and is sparingly soluble in alcohol and ether, readily soluble in benzene. It is a feeble base, and on reduction is converted into paratoluidine and a readily decomposable base. The isomeric bases, C,H,Me (NO2) N2 CH, NMe2

2

crystallising in brownish-red scales melting at 159-160°, and [Me: NO, N2 = 4:3: 1], crystallising in red prisms melting at 146-147°, were prepared for purposes of comparison.

:

If phenylazodimethylaniline is sulphonated with 100 per cent. sulphuric acid at 100°, a sulphonic acid, SO,H·C2H1•N2·C2H1·NMe2, is formed, identical with that obtained by Möhlau (Abstr., 1884, 1149). Paratolylazodimethylaniline can be sulphonated by dissolving it in 100 per cent. sulphuric acid and heating at 100° with sulphuric acid containing 66 per cent. of sulphuric anhydride; the resulting sulphonic acid, SO,H.C&H,Me N2 CH, NMe2, crystallises in violet prisms, and is soluble in hot water and alcohol, yielding, like its salts, red-coloured solutions. On reduction, it is converted into dimethylparaphenylenediamine and metamidoparatoluenesulphonic acid. These experiments were made in conjunction with T. Baumann.

2

2

When phenylazophenol (oxyazobenzene) is nitrated under the above conditions, the nitro-derivative, NO2 CH1•N2·CH ̧·OH, forms the chief product. This crystallises in reddish-brown needles, melts at 211°, and is identical with that obtained from phenol and diazotised paranitraniline. The isomeric nitro-derivatives, [NO, N2 = 1:2], crystallising in orange-yellow needles melting at 126°, and [NO2: N2 1:3], crystallising in red needles melting at 155-157°, were also prepared for purposes of comparison. A dinitro-derivative,

CH3(NO2)2 N2 CH ̧•OH,

:

is also formed during the nitration, and constitutes the chief product if twice the quantity of nitric acid is employed. It crystallises in orange-red needles, melts at 200°, and is identical with the compound obtained from diazotised 1: 2: 4 dinitraniline and phenol. These experiments were made in conjunction with T. Stricker.

W. P. W.

Diazoamido-compounds. By E. NÖLTING and F. BINDER (Ber., 20, 3004-3018).-The authors have prepared the diazoamido-compounds from paratoluidine and diazobenzene chloride and from aniline and diazoparatolyl chloride, and have submitted each to the following reactions, comparing the products throughout:-(1.) Reduction at 0° in alcoholic solution with tin and hydrochloric acid: products, aniline, paratoluidine, phenylhydrazine, and paratolylhydrazine. (2.) Bromination in benzene solution in the cold: products, diazoparatoluene bromide and tribromaniline. (3.) Digestion with a mixture of aniline (2 parts) and aniline hydrochloride (part) at 60° until nitrogen was no longer evolved when a sample was treated with dilute sulphuric acid: products, amidoazobenzene and paratoluidine. (4.) Digestion in like manner with dimethylaniline: products, paratolylazodimethylaniline and aniline. (5.) Digestion with excess of phenol and some sodium hydroxide at 60° until nitrogen was no longer evolved when a sample was treated with dilute sulphuric acid : products, phenylazophenol (hydroxyazobenzene) and paratoluidine. The quantity of phenol employed seems to influence the nature of the product (compare Abstr., 1887, 664). (6.) Digestion with excess of dilute sulphuric acid (1 to 10): products, aniline, paratoluidine, phenol, and paracresol. (7.) Ethylation of the compounds, and decomposition of the products by treatment with dilute sulphuric

acid products, ethylaniline, ethylparatoluidine, phenol, and paracresol. In experiments (3) and (5) the compounds act as if each had the constitution PhN: N.NH.C,H,, in experiments (2) and (4) as if each had the constitution CH, N:N NHPh, whilst from experiments (1) and (6) both formulæ must be ascribed to each of the compounds, and in experiment (7) each compound must have contained both isomerides, unless in this experiment a third isomeride has been formed, as Meldola has been led to conclude is the case when diazoamidometanitroparanitrobenzene is ethylated (Trans., 1887, 110, 443). In all these experiments, no difference could be detected between the two compounds in the course of the reactions or in the nature or relative quantities of the decomposition products, and hence Griess' conclusion that they are identical is confirmed.

The compounds formed by the action of diazoparatolyl chloride on ethylaniline, and of diazobenzene chloride on ethylparatoluidine are isomeric. Paradiazotolylethylanilide, C,H,N: N-NPhEt, is an oil, which cannot be crystallised, and yields paratolylhydrazine and ethylaniline on treatment with nascent hydrogen, paracresol and ethylaniline on digestion with dilute sulphuric acid, and paratolylazophenol and ethylaniline on digestion with phenol. Diazobenzene-ethylparatoluide,

PhNN NEt C,H,,

on the contrary, forms red crystals, melts at 38-39°, and yields phenylhydrazine and ethylparatoluidine on reduction with nascent hydrogen, phenol and ethylparatoluidine on digestion with dilute sulphuric acid, and phenylazophenol and ethylparatoluidine on digestion with phenol.

The compounds formed by the action of diazobenzene chloride on parabromaniline and of parabromodiazobenzene chloride on aniline are identical, and yield parabromaniline and phenol on digestion with dilute sulphuric acid, a result pointing to the formula

PhN N-NH CH,Br.

Diazobenzene chloride reacts with B-naphthylamine to form an amido-azo-compound; a diazo-amido-compound, however, is formed by the action of diazo-ß-naphthyl chloride on aniline. This crystallises in bright yellow needles, melts at 150° with decomposition, and yields aniline, 6-naphthylamine, phenol, and B-naphthol on digestion with dilute sulphuric acid, amido-azobenzene and B-naphthylamine on digestion with aniline, and phenylazophenol and B-naphthylamine on digestion with excess of phenol, the two last results pointing to the formula PhN N⚫NH CH7, which does not accord with its method of formation.

The diazo-amido-compound obtained by the action of diazo-2-naphthyl chloride on aniline yields on digestion with dilute sulphuric acid a mixture of aniline, a-naphthylamine, phenol, and a-naphthol.

The

Diazobenzene chloride does not react with paranitraniline. diazo-amido-compound formed by the action of diazoparanitrobenzene chloride on aniline crystallises in yellow, silky needles, melts at 148°, and yields phenol and paranitraniline on digestion with dilute sul

phuric acid, diazobenzene bromide and bromoparanitraniline on bromination, phenylazophenol and paranitraniline on digestion with excess of phenol, and paranitraniline, aniline, amido-azobenzene, and paranitramido-azobenzene, the last in very small quantity, on digestion with aniline.

Diazobenzene piperide, PhN: N-N: CH10, obtained by the action of diazobenzene chloride on piperidine and sodium acetate in molecular proportion, yields phenol and piperidine on digestion with dilute sulphuric acid, and phenylhydrazine and piperidine on reduction with nascent hydrogen.

Diazobenzenetetrahydroquinolide, PhN: N⚫N: C,H10, obtained in like manner, is a yellow oil, and yields phenol and tetrahydroquinoline when boiled with dilute sulphuric acid. Diazobenzenemethylanilide, PhN N-NMePh, also obtained in like manner, is a yellow oil, which gradually changes, especially if traces of acid are present, into the amido-azo-compound, and yields phenol and methylaniline when boiled with dilute sulphuric acid, and phenylhydrazine and methylaniline on reduction with nascent hydrogen. The compound formed by the reduction of paranitrodiazobenzene chloride on methylaniline is paranitrophenylazomethylaniline, CH ̧(NO2)N : N·C ̧H, NHMe, which crystallises in red needles melting at 134°.

Gasteger has prepared the following:-Diazoparatolylethylparatoluide, C,H,N: N-NEt C, H,, a yellow oil yielding paracresol and ethylparatoluidine with dilute sulphuric acid; diazometanitrobenzeneethylparatoluide, CH,(NO2)N NNEt C,H,, which crystallises in yellow needles, melts at 55°, and yields metanitrophenol and ethylparatoluidine when boiled with dilute sulphuric acid; diazoparanitrobenzene-ethylparatoluide, CH,(NO2)N : N·NEt C,H,, which crystallises in yellow needles, melts at 114-115°, and yields paranitrophenol and ethylparatoluidine when boiled with dilute sulphuric acid. W. P. W.

By E. NÖLTING and A.
N

Constitution of Azimido-compounds. ABT (Ber., 20, 2999-3003).-Hitherto Griess' formula, RNH (Abstr., 1883, 56), for the azimido-compounds has been more generNH ally adopted than the alternative formula, RNN, proposed by Kekulé and by Ladenburg (Ber., 9, 219); the authors, however, bring forward the following evidence in support of the latter, and in addition point out that the formation of acetylazimidotoluene from acetylorthotoluylenediamine (Abstr., 1886, 874) admits of easy explanation on this theory without assuming an intramolecular change, which is necessary if Griess' formula is employed.

When pure ethyltoluylenediamine hydrochloride [NEtH: NH2: Me = 1:24] in concentrated aqueous solution is treated at 0° with sodium nitrite in molecular proportion, ethylazimidotoluene, CH,Me N, Et, is obtained; this crystallises from alcohol in colourless needles, melts at 147°, and is insoluble in water and alkalis, but soluble in the ordinary organic solvents. The hydrochloride is