Page:EB1911 - Volume 27.djvu/276

the various units of the ring system being illustrated in the annexed formulae:—

C C C

N me cmc NI N

C N N / N C/C

N N N

α-Triazines, β-Triazines, Cyanidines.

Few simple derivatives of the α-series are known, those which have been prepared result by such reactions as the condensation of aminoguanidine or a similar type of compound (e.g. semicarbazide) with ortho-dike tones (J. Thiele, Ann., 1898, 302, p. 299):

NH-NH2 OC'CeH5 Nl'l'N

l-lN:C 'i' l -2 HN=C /C'CsHs§

NH2 5 C -CGH5

Wolff has obtained a chloro-derivative by the action of potassium cyanide on diazoacetophenone and subsequent treatment with acid. The phen-a-triazines are more numerous, and are obtained either by the action of concentrated acids on the formazyl compounds (E. Bamberger, Bef., 1893, 26, p. 2786):- C5H5N:N~ NrN

v/C-COCGHB s C@Hf, NH2--CSH4 I

C5H5'NH'lN N-C'COC6H5;

by the reduction of symmetrical acyl-ortho-nitrophenyl hydra zines (e.g. N02-CGH4-NH-NH~CHO); or in the form of dihydro derivatives by the condensation of aldehyde's with ortho-aminoazo compounds (H. Goldschmidt and Y. Rosell, Bef., 1890, 23, p. 487), or from the aminoazo compound and a mustard oil, the resulting thiocarbanilido derivative being heated with acetic acid (M. Busch, Bef., 1899, 32, p. 2960) 1/N-C(SH)'N-CsHs /N-C'NCsHs

C;H/ ' scH/ ' +Hs.,

°N-NH~c.H. 7 6N-N-C7H7 2

C. Harries (Ben, 1895, 28, p. 1223) has also shown that as-phenylhydrazino-acetic esters, when heated with form amide and substituted form amides under pressure, yield dihydrotriazinesicqi R CO-NR'-CH

CH, .N(C5H5)NH2+R “WHO 9 cH.~N<c.H.>-N ', The phen-a-triazines are yellow-coloured crystalline compounds of a somewhat basic character.

Derivatives of B-triazines are formed by the action of nitrous acid on ortho-aminobenzylamines (M. Busch, B87'.', 1892, 25, p. 445), or in small quantity by the action of nitrous acid on ortho-aminobenzoylphenylhydrazines (A. Konig and A. Reissert, Bcr.. 1899, 32, p. 782), the chief product in this latter reaction being an isoindazolone:

/CHg-Nl'lC¢;l'{;, Clrlg-NH~C6l'l.; /CH2~NC¢;l'l5 Celi4 9 CsHi 9CeH4 i-NH;-HCl

N:NCl NZN

The best drawn series of the triazines cyanidine series, members of which result of acid anhydrides with aromatic amidines 25' P' 1624): NH N c c H

A ' ' 6 5

2c.H, -c< +(CH3CO)2O 9 c.H.~c< >N; NH2 N IC-CH3

or by the condensation of aromatic nitriles with acid chlorides in the presence of aluminium chloride (Eitner and Krafft, Bef., 1892, 25, p. 2263). In using benzoyl chloride in this reaction the condensation is found to proceed better if a little ammonium chloride be added:

is the symmetrical or

from the condensation

(A. Pmner, Ber., 1892,

Cf, H, »C-Cl OC-C@H5

2C¢H. +C5Hu $ Q/

N -C(C¢H5):N

The cyanidines behaveas weak bases. Mention may be made here of cyanuric acid, H3C3N3O3, which ring system as the cyanidines. It was first prepared by C. Scheele and is formed when urea is strongly heated or when cyanuric chloride is treated with water. It is usually represented by the inset formula and is closely related to cyanic acid and c yam elide, the relationships existing between the three compounds being shown in the diagram (see also A. Hantzsch, Ber., 1906, 39, p. 139): Contains the same

N-c-OH

HOC/ N

N:(T4OH

Ordinary

temperature / Cyamelid Decomposes easily (CNOH)3

Cyanic acid/ CO NH

CNOH HO ions Z 2+~ =

l/ /, /

High temperature ; Cyanuric acid; Decomposes with difficulty.

TRIAZOLES (pyrro-α and β′-diazoles), in organic chemistry, a series of hetero cyclic compounds containing the ring complex (annexed formula). Derivatives were obtained by J. A. Bladin HC;:N (Bela, 1892, 25, p. 183) by the action of acetic I >NH an hydride on dicyanophenylhydrazine, (formed N i CH from cyanogen and phenylhydrazine), the resulting acetyl derivative losing water and yielding phenylmethylcyanotriazole, which, on hydrolysis, gives the free acid. By eliminating carbon dioxide, phenylmethyltriazole results. In a similar manner, formic acid and dicyanophenylhydrazine yields a phenyl-triazole carboxylic acid, in which the phenyl group may be nitrated, the nitro group reduced to the amino group, and the product oxidized to a triazole carboxylic acid, which, by elimination' of carbon dioxide, yields the free triazole:

HOQC-C-:N HOZC-C:N HO2C~C =N

1 NPh9 l NCeH4NH2»> 1 NH.

N:CH N:CH N:CH

They also result when the acidylthiosemicarbazides are strongly heated, the mercapto-triazoles so formed being converted into triazoles on oxidation with hydrogen peroxide (M. Freund, Bef., 1896, 29, p. 2483); by the condensation of hydrazides with acid amides; and by the distillation of the triazolones (see below) with phosphorus pentasuiphide. The triazoles behave as weak bases, the imido-hydrogen being replaceable by metal. The keto-dihydrotriazoles or triazolones are obtained by the action of hydra zines on acetyl urethane (A. Andreocci, Bef., 1892, 25, p. 225). These compounds may be considered as 5-triazolones, a series -of isomeric 3-triazolones resulting from the condensation of phenylsemicarbazide with aromatic aldehyde's in the presence of an oxidant. The diketotetrahydrotriazoles, or urazoles, are formed by condensing urea derivatives with hydrazine salts, urazole itself resulting by the action of urea or biuret on hydrazine or its salts. It behaves as a strong acid and on treatment with phosphorus pentachloride at high temperatures gives triazole. HC:N CO-NH CO~NH

| /NH, 1 >NH, >NH.

HN-CO N:CH NH»CO

5-Triazolone. 3-Triazolone. Urazole. Isomeric triazoles of the following constitutions are known:- HC:N N:CH N: N

1 /NH | >NH | /NH

HC:N N:CH HC:CH

Osotriazole (a.a'). lminotriazole (B/3'). a.{5'»'l'riazole. The osotriazoles are obtained by heating the osazones of or tho dike tones with mineral acids; by the action of acetic an hydride on the hydrazoximes of or tho dike tones, or by condensing diazo-methane with cyanogen derivatives (A. Peratones and E. Azzarello, R. Acad. Lincefi, 1907 [v.], 16, pp. 237, 318). They are feeble bases which distil unchanged. The ring is very stable to most reagents. The iminobiazoles are formed by conversion of diacylhydrazines into iminochlorides which with ammonia or bases yield the required triazoles (R. Stollé, Journ. prak. Chem., 1906 [ii.], 74, pp. 1, 13). M. Busch (Ben, 1905, 38, pp. 856, 4049) has isolated a series of bridged ring compounds which he describes as endo-iminodihydrotriazoles, the triphenyl derivative (annexed formula) being prepared by condensing triphenylaminoguanidine with formic acid. The nitrate of this base (known as nitron) is so insoluble that nitrates may be gravimetrically estimated with its help. These bases combine with the alkyl iodides triazolié to yield quaternary ammonium salts.

TRIBALLI, in ancient geography, a Thracian people whose earliest home was near the junction of the Angrus and Brongus (the east and west Morava), and included towards the south “the Triballian plain” (Herodotus iv. 49), which corresponds to the plain of Kossovo in Turkey. In 424 B.C. they were attacked by Sitalces, king of the Udrysae, who was defeated and lost his life in the engagement. On the other hand, they were overcome by the Autariatae, an Illyrian tribe; the date of