Diazoaminobenzene, preparation

It is prepared by an intramolecular transformation of diazoaminobenzene in the presence of aniline hydrochloride, or in one stage by diazotizing a solution of aniline and aniline hydrochloride with an insufficient amount of nitrous acid. 

The recrystallisation of diazoaminobenzene has to be performed with care, as the substance is freely soluble in most liquids and tends moreover to decompose if its solution is not rapidly cooled. Place 2 g. of the crude, freshly prepared, well-drained material in a boiling-tube, add about 15-20 ml. of ethanol and 1-2 drops of 10% aqueous sodium hydroxide solution, and then heat rapidly until boiling if the solution should contain insoluble impurities, filter through a small fluted paper, and at once cool the filtrate in ice-water. The diazoaminobenzene should rapidly crystallise out from the cold and stirred solution filter the crystals rapidly at the pump whilst the solution is still cold, as... 

Attention has previously (see Diazonium Sails) been drawn to the fact that unless an excess of hydrochloric (or mineral) acid is used in the diazotisation process, coupling occurs between the diazonium salt and the amine to give diazoamino compounds. Thus phenyldiazonium chloride and aniline yield diazoaminobenzene. This substance may be conveniently prepared by dissolving two equivalents of aniline in three equivalents of hydrochloric acid, and adding one equivalent of sodium nitrite in aqueous solution followed by two equivalents of sodium acetate ... 

Diazoaminobenzene has been prepared by the action of sodium nitrite on aniline sulfate by the action of sodium nitrite on aniline hydrochloride by the action of sodium nitrite and sodium acetate on aniline hydrochloride by the action of ammonium nitrate and hydrogen sulfide on aniline hydrochloride in the presence of iron and by the action of amyl nitrite on aniline. ... 

Diazoalkane complexes, in preparation of diazenido complexes, 27 222 Diazoaminobenzene-copper complex, 2 39 Diazobutadiene compiexes with iron, 12 274, 275... 

Bright yellow complexes of halogeno derivatives of diazoaminobenzene and Ag have been prepared the structure (52) has been proposed on the basis of i.r. evidence.2 11 I.r. studies of mixed complexes between AgNOa and thiazole thiones (53) and... 

Polymeric complexes are formed when copper(I) chloride reacts with dialkylhydrazines (105) or with 3,5,5-trimethylpyrazolidine. In Cu2Cl2(MeN=NMe) the structure consists of parallel Cl-Cu-Cl chains cross-linked by weak Cu-Cl bonds and strong Cu-N a bonds (47). Structures of CuI(PhN=NH) and Cu4Cl4(PhN=NH) may be similar (282, 290). Diazoaminobenzene copper(I) (110, 245) can be prepared from copper and the ligand it is dimeric with each copper linearly coordinated to 1,1 iV or 3,3 N atoms (48). The cation in [Cu(PhN2Ph)]-CIO4 may have a related structure (265). 

A) Preparation of Diazoaminobenzene. Place in a 150-ml beaker 5 ml of water, 1 ml of aniline, and 1 ml of concentrated hydrochloric acid. Stir, and add 15 ml (0.015 moles) of the benzenediazonium chloride stock solution prepared in Experiment 53 (C). Add 1.5 ml of Q N sodium hydroxide solution drop by drop while stirring. Allow to stand, and proceed with section (B). Later filter the compound, wash several times with water, press, and remove to paper to dry. The yield is 1.8-2.2 g. 

Diazoaminobenzene crystallizes in yellow plates, which melt at 98° it explodes when heated above its melting-point. It is insoluble in water, and is soluble in benzene, ether, and alcohol. The yield obtained in the above preparation is about 15 grams. 

Diazoaminobenzene has also been prepared by the action of nitrous acid gas on aniline in alcohol 1 2 4 6 by the action of silver nitrite on aniline hydrochloride 7 and together with phenylurea by the action of nitrosophenylurea on aniline in methyl alcohol.8 Niementowski and Roszkowski9 have reported studies on the diazotization of aniline, aniline hydrochloride, and aniline sulfate with sodium nitrite and silver nitrite. The procedure described is adapted from that of Fischer.3... 

The diazo-compounds form the starting point of numerous organic compounds, including the azo-dyes, the first representative of which (amino-azobenzene hydrochloride, aniline yellow ) was prepared and shown to be a dye by Mene. What was called aniline yellow is the oxalate of aminoazo-benzene (CeH5 N N-CeH4 NH2), introduced as a dye by Simpson, Maule, and Nicholson in 1863 its constitution was established by C. A. Martius and Griess, and the isomeric change of diazoaminobenzene into aminoazobenzene was explained by Kekule. ... 

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