1.2- Diphenylhydrazine, reaction with

Viehe and coworkers have used dichloromethyleneammonium salts (604) to obtain 5-dimethylaminopyrazoles (605) from A -methylhydrazones (74AG(E)79). The same reagent (604) affords 3-dimethylaminoindazoles (606) by reaction with Af,Af-diphenylhydrazine... 

Diphenylhydrazine is oxidized to diphenylnitrosamine (50%) by potassium superoxide. The same reagent also oxidizes 1-methyl-1-phenylhydrazine, but here the nitrosamine is a minor product the major reaction is deamination. A better meAod of oxidative deamination of some 1,1-disubstituted hydrazines and hydrazinium salts is reaction with nitrous acid. Thus, several hydrazinium salts MezRN NHi X were deaminated to the tertiary amine by treatment with nitrous acid. The method has also been used to deaminate IV-aminoheterocyclic compounds for example, some 1,2,3-triazoles are conveniently prepared by deamination of the corresponding 1-aminotriazoles with nitrous acid. °... 

Unsymmetrical disubstituted hydrazines (1,1-diphenylhydrazine and 1,1-dimethylhydrazine) do not exhibit a detectable reaction with O2"- in the gas phase nor in Me2SO within approximately 10 min. This is consistent with the hypothesis that only those substituted hydrazines with a secondary amine function react with O2 - by hydrogen-atom transfer. Although there is a report that 1,1-diphenylhydrazine reacts with superoxide ion to produce N-nitrosodiphenylamine, such a product is more consistent with a peroxide reaction (a likely possibility for the reaction conditions). 

There are no electrophilic aromatic substitution reactions, analogous to those of S-dications or Se-dications, reported in the literature involving the Te-dication (58). As expected, the oxidant properties of the Te-dication are observed in reactions with 1,2-diphenylhydrazine and with benzene thiol where oxidation products, azobenzene and diphenyl disulfide, are obtained respectively. Unlike its S-dication counterpart, the Te-dication does not undergo hydrolysis with water and retains its oxidant properties. NaBH4 reduction converts the Te-dication (58) into the cyclic bis-telluride (59) <91TU537>. 

Glyoxalate, the product of chemical hydrolysis of allantoin and allantoic acid, is most frequently measured after reaction with diphenylhydrazine. The most commonly used procedure to measure ALN and ALA involves add or base hydrolysis to produce glyoxalate, reaction with phenylhydrazine at neutral pH to produce the phenylhydrazone of glyoxalate, and oxidation of the phenyl-hydrazone with ferricyanide and strong add to form the diphenylformazan (Vogels and Van der Drift, 1970). The colored l,S-diphenylformazan (shown below) formed absorbs strongly between 520 and 540 nm with a molar extinction coefficient of 51,0(X) (Matsui et al, 1965). 

Interaction, in presence of diluent below 0°C, with isopropylamine or isobuty-lamine caused separation of explosive liquids, and with aniline, phenylhydrazine and 1,2-diphenylhydrazine, explosive solids [1], In absence of diluents, contact with most aliphatic or non-aromatic heterocyclic amines often leads to uncontrolled oxidation and/or explosions [2], During oxidation of two steroidal dienes in dry pyridine at —35 to —40°C, on one occasion each of the reactions was accompanied by violent explosions [3],... 

Another example of a Tc nitrido-complex is obtained from the reaction of [TcOCU]" with 1,1-diphenylhydrazine (H2NNPh2) (23) in the presence of thiophenol. Unexpectedly, the dinuclear, formally Tc complex [ TcN(NNPh2)(SAr)(/r-SAr) 2] (24) is formed in good yields. The nitrido-group results from the cleavage of the organohydrazine. This unusual reaction is shown in Scheme 9. 

A further example is provided by the reaction of l-chloro-2,4,6-trinitrobenzene (picryl chloride) with jV,jV-diphenylhydrazine to give N,N-diphenylpicrylhydrazine (Expt 6.94). This compound is of interest in that... 

Bums and coworkers have discovered a remarkable reaction involving Cp 2U(Me)Cl. Treatment of the latter with l-lithio-l,2-diphenylhydrazine in ether solution generates lithium chloride and methane, and provides the uranium(VI) bis-imido compound Cp 2U(NPh)2, conceivably via a uranium(lV) hydrazido species Cp 2U( ] -PhNNPh)." A plausible reaction sequence is laid out in equations (61) and (62). Cp 2U(NPh)2 was the first uranium(Vl) organometallic complex. In the solid state, Cp 2U(NPli)2 adopts the famihar... 

Support for the general mechanism outlined in equation (153) is provided by gas-phase Fourier transform mass spectrometric studies of the anionic reaction products of several substrates with O, (produced by electron impact with O2 HO can be produced by electron impact with H20). In these experiments, neutral products are not detected. Both 02 and HO react rapidly with 1,2-diphenylhydrazine in the gas phase (P 10 Torr) to give the anion radical of azobenzene (PhN NPh m/e = 182) and the anion Irom deprotonation (PhNHNHPh mje = 183), respectively. When 02 is ejected from the experiment, the peak exponential decay that is observed for the HO peak with time, the ion current for 0, decays to a steady-state concentration. 

The photolysis of tetraphenylhydrazine (I), triphenylhydrazine (II) and sym-diphenylhydrazine (III) at 3150 A at liquid nitrogen temperature was examined qualitatively in epa . The progress of the photolysis was followed both optically by spectrophotometry and also with esr which detected the PHjN- radical in a steady state concentration. The photolysis of (I) and (II) leads to photofission of the N-N bond, and in the latter case PhjN and PhNH- are detected. The reaction of (III) appears to be different and also to involve some photooxidation or photoionization. 

Ethyl 3-ethoxy-a-nitroacrylate with 1,1-diphenylhydrazine in ethanol followed by heating has been shown to give l,4-bis(diphenylamino)-2,5-diethoxycarbonyl-l,4-dihydropyrazine (1586). A small amount of 2,5-dicyano-l,4-bis(dimethylamino)-1,4-dihydropyrazine was obtained from the reaction of 2-chloro-3-(2, 2-dimethyl-hydrazino)propionitrile [(Me)2NNHCH2CH(Cl)CN] with sodium hydride (1587). Hexaalkyl-l,4-dihydropyrazines and other 1,4-dialkyl-1,4-dihydropyrazines can be obtained by thermolysis of the products of reaction of a-(alkylamino)carboxylic acid esters with alkylmagnesium bromide. Thus the reaction of ethyl a-s-butyl-aminopropionate with ethylmapesium bromide, followed by heating in vacuo to 250-300°, gave 2,5-dimethyl-3,6-diethyl-l,4-di-s-butyl-l,4-dihydropyrazine (1588). 

Reaction of a 3-aryl-l,2-dithiolium cation with phenylhydrazine gives a mixture of pyrazoles. Similarly, with a 4-aryl-l,2-dithiolium ion, 1,2-dimethyl- or 1,2-diphenylhydrazine give a pyrazolium ion. With hydroxylamine poor yields of mixtures of isoxazoles and isothiazoles are obtained. 

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