Ammonia with diazo compounds

The formation of hydrazoic acid and its derivatives together with ammonia from diazo compounds under the influence of hydrazine or its derivatives was explained by Thiele [68]. At an intermediate stage a diazohydrazine, e.g. C6H5N2NHNH2, is formed which then undergoes decomposition according to two parallel reactions ... 

Several of these acids are known, but only one, the caustic soda on /8-naphthylaminedisulphonic acid G (from /S-naphtholdisulphonic acid and ammonia) at about 260°. It may be diazotised, and reacts with diazo-compounds to produce azo-colours, which may be diazotised and combined on the fibre with other amines and phenols. (See below, under Tetrazo-colours.)... 

The reaction of diazo compounds with amines is similar to 10-15. The acidity of amines is not great enough for the reaction to proceed without a catalyst, but BF3, which converts the amine to the F3B-NHR2 complex, enables the reaction to take place. Cuprous cyanide can also be used as a catalyst. The most common substrate is diazomethane, in which case this is a method for the methylation of amines. Ammonia has been used as the amine but, as in the case of 10-44, mixtures of primary, secondary, and tertiary amines are obtained. Primary aliphatic amines give mixtures of secondary and tertiary amines. Secondary amines give successful alkylation. Primary aromatic amines also give the reaction, but diaryl or arylalkyl-amines react very poorly. 

With less electron-rich pyrroles, hydrochloric acid can be used in the diazotization. The diazo compounds were isolated after neutralization with aqueous ammonia [84H(22)2269]. 3-Diazo-2,5-diphenylpyrrole, although efficiently prepared by diazotization of the 3-aminopyrrole, can also be prepared by oxidation of the 3-nitrosopyrrole with dinitrogen trioxide (60JCS3270). Pyrrole-3-carboxylic acid, with buffered nitrous acid, gave the 3-diazo derivative 295 by displacement of the carboxyl group, together with the 3-diazo-2-carboxylic acid 296, obtained by further hydrolysis (62JCS1638) (Scheme 90). 

Among the organic nitrogen compounds having nitrogen above the oxidation level of ammonia are a wide variety of substances with N-N bonds. We shall mention only a very few of the more important of these substances hydrazines, azo and diazo compounds, and azides. 

Of the methods for the preparation of this substance two would seem best suited for laboratory use In the first place, one can start with w-nitraniline, diazo-tize this, and decompose the diazo compound by boiling with dilute acid, forming t-nitrophenol, but as the yield is not very good and the mtrophenol must subsequently be reduced to the amino compound, the method is scarcely suited for the preparation of considerable amounts of this material. On the other hand, the method involving the direct replacement of one of the hydroxyl groups of resorcinol, t-C6H4(OH)2 by ammonia, was found to be very satisfactory. 

Aiiiino-4-phenylthiazoles, from o-diazo-acetophenone and thiourea, 231 2-Amino-5-phenylthiazole, diuretic prope ties of Schiffs bases of, 167 synthesis of, by condensation of ammonia with At(ary 1-1,3-oxathiol-2-yIidine) tertiary iminium salts. 300 2-(p-Ammophenyl) thiazoles, syntheses of, 4,5-disubstituted derivatives of, 191 2-Amino5-substituted thiazoles, from o-haloaiddiydes and thiourea, 224, 225 /V,At -bis (2-Amino-4 substituted thiazolyl)-p biphenylene, from p-biphenylene dithiourea and o-halocarbonyl compounds, 243... 

The melt is extracted with water, and the residue dissolved in hot alcohol, and ammonia gas passed into the solution. The precipitate which forms is boiled with acetic acid or hydrochloric acid [44, 48, 49]. Aurin is also formed by condensation of phenol with formic acid and zinc chloride [45], by boiling the diazo-compound from pararosaniline with water [12], by heating dioxybenzophenone chloride with phenol [46], and by action of salicylic aldehyde on phenol in presence of concentrated sulphuric acid [47]. 

Three-membered rings with two heteroatoms are usually encountered only as reagents. Diazirines are nsefnl carbene precnrsors" - they are generally more stable than the equivalent isomeric diazo compounds, thongh they are sometimes explosive in the pure state. They can be prepared by oxidation of diaziridines that, in tnm, are available via the condensation of a ketone or aldehyde with ammonia and chloramine. Chloro-diazirines, from the reaction of amidines with hypochlorite, wiU undergo Sn2 or Sn2 displacement reactions."" ... 

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