Benzene diazonium chloride

It is prepared commercially by treating benzene diazonium chloride with sodium sulphite and then reducing the mixture with zinc dust and ethanoic acid. It can also be prepared by reduction of benzene diazonium chloride with SnCl. ... 

In preparing an aqueous sol ution of a diazonium salt, such as benzene-diazonium chloride, it is usual to dissolve the amine in a slight excess (about 2 2 molecular equivalents) of dilute hydrochloric acid (or alternatively to dissolve the crystalline amine hydrochloride in i 2 equivalents of the acid) and then add an aqueous solution of a metallic nitrite. Nitrous acid is thus generated in situ, and reacts with the amine salt to give the diazonium compound. For a successful preparation of an aqueous solution of the diazonium salt, however, two conditions must always be observed ... 

When diazoaminobenzene is added to a warm aqueous solution of hydrochloric acid, it tends to break up into its original components, i.e., to benzene-diazonium chloride and aniline, and an equilibrium is thus established. The diazonium chloride and the aniline, however, in addition to recombining to form diazoaminobenzene. also undergo direct condensation at the p-hydro-... 

Primary aromatic amines differ from primary aliphatic amines in their reaction with nitrous acid. Whereas the latter yield the corresponding alcohols (RNHj — ROH) without formation of intermediate products see Section 111,123, test (i), primary aromatic amines 3neld diazonium salts. Thus aniline gives phcnyldiazonium chloride (sometimes termed benzene-diazonium chloride) CjHbNj- +C1 the exact mode of formation is not known, but a possible route is through the phenjdnitrosoammonium ion tlius ... 

N,N -Diethylbenzidine has been prepared by heating ethyl iodide, benzidine, and ethanol in a pressure tube at water-bath temperature, and by the reaction of diethylzinc on benzene-diazonium chloride. The method described here is a modification of that of Shah, Tilak, and Venkataraman. ... 

Diethylamino-4-methylselenazole was coupled by Haginiwa with benzene diazonium chloride to yield the corresponding 5-azo compound, which formed orange colored granules, mp 101°C. ... 

Specific diazonium compounds are found under the heading of the parent compound, e.g., C6H5N2 Cl- under benzene, diazonium chloride . 

The diazonio group of one zwitterion is stabilized by intermolecular interactions with the carboxylato oxygens of two neighbouring zwitterions. The same type of coordination is observed in crystals of benzene diazonium chloride, tribromide, and tetrafluoroborate (Andresen and Romming, 1962 Romming, 1963 Cygler et al., 1982). 

The experiment was carried out with (i )-(-)-2[l-(methoxycarbonyl)ethyl]benzene-diazonium chloride (6.80). The product, methyl 3-methyl-3-//-indazole-3-carboxylate (6.81), was racemic. With regard to the inconclusive H/D exchange experiments one therefore has to conclude that the cyclization of the diazo-methylene intermediate 6.75 is faster than the rate of deuterium incorporation. 

Hydrolysis of the condensate gives LXIII and this by the agency of methyl alcoholic alkali affords the enol form of 2-desoxy-L-ascorbic acid (LXIV). 1 When the latter is allowed to react with benzene diazonium chloride there is formed the mono(phenylhydrazone) LXV from which... 

Phenylhydrazine has been prepared by the reduction of benzene diazonium salts with sulfites 1 by the reduction of benzene diazonium chloride with stannous chloride 2 by the reduction of benzene diazonium hydrate with zinc or sulfur dioxide 3 by the reduction of sodium benzene diazotate with sodium stannite 4 by the reduction of diazoamino benzene 5 by the reduction of nitrosophenyl hydroxylamine or its methyl ether 6 and by the action of hydrazine hydrate on phenol.7... 

The azo produets obtained have an extended conjugate system having both the aromatie rings joined through the -N=N- bond. These compormds are often coloured and are used as dyes. Benzene diazonium chloride reacts with phenol in which the phenol molecule at its para position is coupled with the diazonium salt to formp-hydroxyazobenzene. This type of reaction is known as coupling reaction. Similarly the reaction of diazonium salt with anUtne yields p-aminoazobenzene. This is an example of electrophilic substitution reaction. 

A) (23), was obtained in an improved yield using the modified literature procedure (28) starting from benzene diazonium chloride (1054) and hydroxymethylene-5-methylcyclohexanone (1055). A biomimetic coupling of l-hydroxy-3-methylcarba-zole (O-demethylmurrayafoline A) (23) by reaction with di-ferf-butyl peroxide l(t-BuO)2] afforded the dimer of O-demethylmurrayafoline A (204). Finally, oxidation of 204 with PCC afforded (+ )-bismurrayaquinone-A (215). The resolution of atropo-enantiomers was achieved by chiral HPLC using Chiracel OF. The assignment of the absolute configuration of the two enantiomers (S)-215 and (f )-215 was achieved by comparison of their theoretical and experimental circular dichroism (CD) spectra (166,167,661) (Scheme 5.164). 

The same compound is also obtained together with aminodiazobenzene, when benzene diazonium chloride or sulfonate reacts with benzamid-oxime 101). When heated in dilute mineral acid, XXVI readily loses NH3 to yield diphenyloxadiazole. 

The chem reaction between LiNa and benzene diazonium chloride has been described by Huisgen (Ref 20). The formation of an exp I Lithium Boroazide, LiB(N3)4, a wh solid sol in ether, easily hydrolyzed and very sensitive to impact and pressure was reported by Wiberg Michaud (Ref 19). This compd was obtd on evapg to dryness a mixt of ether solns of excess HN, and LiBfi, Li azide and B azide were assumed as intermediate products in the stepwise reaction... 

Benzene diazo- and diazonium derivs 2 B54—B58 chemistry, definition and history 2 B54—B55 benzene diazonium chloride 2 BS5 benzenediazonium hydroxide and derivs 2 B55—BS6... 

Benzene Diazonium Chloride(Diazobenzene Chloride), C6H5.N2.C1-, mw 140.57, N 19.94%, OB to C02 -165% col ndls(from ale by pptn with eth), readily sol in w or cold AcOH sol in abs ale or acet insol in benz, chlf, eth or ligroin. Can be prepd by reacting equim amts of aniline and sodium nitrite in the presence of an excess of a mineral acid at low temp(0-5°). Other methods of prepn and props are given in the Refs. Its toxicity is unknown(Ref 4)... 

C6H8N N)2N.CH2.COOH mw 283.28, N 24.72% crysts m" expl 124° was prepd from glycine(amino-acetic acid), NaOH and benzene-diazonium chloride at 0°... 

The details of this preparation are practically the same as those given for p-tolu-nitrile (Preparation 82). A cuprous-potassium cyanide solution, prepared as therein described, is warmed to about 70°, and added in small portions to a solution of benzene-diazonium chloride prepared from 18-6 gms. (1 mol.) of aniline as described in Preparation 379. When the addition is complete, the liquid is warmed on a water bath for 15 minutes and distilled in steam the distillate is extracted with ether. The ethereal solution is washed repeatedly with dilute caustic soda and with dilute sulphuric acid, dried over anhydrous potassium carbonate, filtered, and the oil which remains on driving off the ether fractionated. Owing to the evolution of cyanogen and hydrocyanic acid, this preparation must be carried out in a good fume cupboard. 

Macrae and Wright (96) demonstrated that visible light irradiation of xanthene dyes (eosin, erythrosin, rhodamine B, or RB) in ethanolic solutions of 4-(N,N-diethylamino)benzene-diazonium chloride (as the zinc chloride double salt) resulted in decomposition of the diazonium salt. Electron transfer from the dye excited state(s) to the diazonium salt was postulated and dye-diazonium salt ion pair formation in the ground state was shown to be important. Similar dyes and diazonium salts were claimed by Cerwonka (97) in a photopolymerization process in which vinyl monomers (vinylpyrrolidone, bis(acrylamide)) were crosslinked by visible light. Initiation occurs by the sequence of reactions in eqs. 40-42 ... 

Arsinic acids and arsine oxides may be prepared by extensions of the t Bart synthesis. Thus, diphenylardnic acid is obtained from benzene- diazonium chloride and disodium phenylarsenite. 

Amino 1 naphthol 1 Naphthol + benzene diazonium chloride followed by sodium hydrosulfite... 

Benzonitrile (1) Toluene + NH3 (2) Sodium benzene sulfonate + NaCN (3) Benzene diazonium chloride + NaCN... 

Since iq is fairly constant, the reaction is first-order Example The following data are obtained for the hydrolysis of benzene diazonium chloride C6H5N = N - Cl + H20 —> C6H5OH + HC1 + N2(g) ... 

An amino group has been introduced at the 5-position of the thiazolidine-dione nucleus by coupling of the reactive methylene group with benzene-diazonium chloride at 0°-5°, followed by reduction of 102 with sodium hydrosulfite [Eq. (31)].142 The tautomeric structural assignment of 102 has... 

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