Phenylhydrazine, reaction with studies

Kinetic studies of hexacyanoferrate(III) oxidations have included the much-studied reaction with iodide and oxidation of the TICI2 anion, of hydrazine and hydrazinium, and of phenylhydrazine and 4-bromophenylhydrazine. These last reactions proceed by outer-sphere mechanisms, and conform to Marcus s theory. Catalyzed [Fe(CN)g] oxidations have included chlororuthenium-catalyzed oxidation of cyclohexanol, ruthenium(III)-catalyzed oxidation of 2-aminoethanol and of 3-aminopropanol, ruthenium(VI)-catalyzed oxidation of lactate, tartrate, and glycolate, and osmium(VIII)-catalyzed oxidation of benzyl alcohol and benzylamine. ... 

Further work related to the cyclization of the nitrile imides, generated from N-o-nitroarylhydrazidoyl bromides, has appeared ( ), and the reaction of hydrazidoyl halides with azide ion and phenylhydrazine has been studied. Lozinskii et al. have shown that chlorooxalylarylhydrazidoyl chlorides (see Chapter 7) react with azide ion preferentially on the halo group attached to the carbonyl group. 

DFT calculations have probed electronic effects in the reaction of 2-arylhydrazono acetic acid with pyruvic acid to give (2Z)- and (2 )-3-aryl acrylic acids. Rearrangement of 11 (Z)-arylhydrazones of 5-amino-3-benzoyl-l,2,4-oxadiazole to give 2-aryl-5-phenyl-(2//-triazol-4-yl)ureas has been studied in toluene, with catalysis by TEA or piperidine, and compared to earlier results in more polar media. The kinetics of the acetophenone-phenylhydrazine reaction has been studied for a variety of solvents and ketone ring substituents. ... 

Thiocoumarin reacts with phenylmagnesium bromide to give a mixture of 2-phenyl-A -thiochromene and thioflavone, the latter product being presumed to arise by oxidation of 4-hydroxy-2-phenyl-A -chromene, formed via a thiopyrylium cation. 4-Hydroxythiocoumarin has been acetylated at the 3-position, by treatment with acetic acid and phosphorus oxychloride reactions of the product with amines and with phenylhydrazine have been studied. ... 

From a study of the spectral properties and reaction with 2,4-dinitro-phenylhydrazine Wiss and Bettendorf 329) postulated that the intermediate was 2-acroleyl-3-aminofumarate (l-amino-4-formyl-buta-l,3-... 

The reaction appears to be second order during the initial growth state with specific rate constants similar to those found for reaction with simple monoamines. After the initial relatively rapid growth period, product formation slows, but proceeds through several days reaction time. Reaction yields after 24 h varied from about 14% for phenylhydrazine to 70% for 4-nitrophenylhydrazine. Two tumor lines were studied. Both the L929 and HeLa were inhibited at a concentration of 12 p,g/mL. 

Nareeine eontains three methoxyl and two methyl-groups attached to nitrogen, reaets with phenylhydrazine or hydroxylamine, furnishing phenylhydrazone or oxime anhydrides and esterifies with aleohols in presence of hydrogen chloride. From a study of these reactions, and in... 

Katritzky and co-workers studied the mechanism of this reaction in detail. His work involved a NMR study of 16 reactions of methyl-, phenyl-, 1,2-dimethyl-, and l-methyl-2-phenylhydrazine with /3-keto esters. In many cases starting materials, intermediates, and products were detected simultaneously. Most reactions proceed by nucleophilic addition of the less hindered hydrazine nitrogen atom to the keto carbon of the keto ester. For example, the pathway given in Scheme 3 for the reaction of methyl 3-oxobutanoate 9 with methyl- or phenyUiydrazine 2 (R = Me or Ph) was found to be dominant. The initially formed addition product 10 dehydrates to hydrazone 11, which then isomerizes to hydrazone 12. Intermediate 12 then cyclizes to pyrazol-3-one 13, which tautomerizes to the kinetically more stable pyrazol-3-otie 14 [87JCS(P2)969]. 

The interaction of PCSs with nucleophilic reagents was studied by us we took the reactions of hydrazine and phenylhydrazine with polyazines, poly(schiff base)s, and other polymers containing conjupted C=N bonds as an example40,41, U7,258. ... 

The reaction of these aldehydes, derived from periodate oxidation, with carbonyl reagents has also been investigated. Studies 147 148 were made on oxidized laminarin, a (1 —> 3)-linked polysaccharide, in which only the terminal residues had been oxidized. The addition of phenylhydrazine acetate detached the remainder of the terminal residue as glyoxal phenyl-osazone. When the aldehydic compounds derived from the periodate oxidation of raffinose and trehalose818a were reacted with p-nitrophenylhydrazine, the authors were surprised to find that one molecule of oxidized raffinose, containing six aldehydic functions, reacts with only three molecules of the reagent, and that the four aldehydic functions of the oxidized trehalose molecule react with only two. The reactions of periodate-oxidized carbo-... 

Iwakawa et al. studied the reaction of 3-acetonyl-5-cyano-l,2,4-thiadiazole 72 with a series of 4-substituted phenylhydrazine hydrochlorides. When electron-donating substituents were used (e.g., methyl and methoxy) in the phenyl ring of the hydrazine, the reaction proceeded via a Fischer-indole mechanism to give indoles 73 as the sole product. In contrast, reaction of 72 with phenylhydrazine and 4-chlorophenylhydrazine gave only small amounts of indole 72, but much higher yields of the pyrazole 74. The authors described in detail the respective reaction mechanisms... 

It has been shown by H naff (1963) that the rate of reaction of several carbonyl reagents (bisulphite, hydrazine, phenylhydrazine, semi-carbazide and hydroxylamine) with aqueous formaldehyde solutions is independent of the nature and concentration of the reagent, and is therefore determined by the rate of dehydration of methylene glycol. He obtained catalytic constants for hydrogen and hydroxide ions, and a detailed study of acid-base catalysis has been made by the same method by Bell and Evans (1966). 

Reactions characterizing aziridinyl ketones as polyfunctional compounds are also described in the literature. An example is a widely studied [11, 15, 72, 73, 74] reaction of ketones 18 with phenylhydrazine in which the main products are pyrazole derivatives 55. 

Fig. 9. Fischer s phenylhydrazone reaction85 and the glycoblotting method first demonstrated by using aminooxy-functionalized synthetic polymers. (A) Reaction of sugars with phenylhydrazine (B) the general concept of glycoblotting and (C) the aminooxy-functionalized synthetic polymers used in the preliminary study.84 (Original figure made by the author.)...

The reaction of oxyhaemoglobin with phenylhydrazine was studied in whole blood samples (Maples et al., 1988). Hydrazine-based drugs induce destruction of red blood cells with resulting haemolytic anaemia. Using DMPO as a trap, nitroxide radicals were detected, but these had solid-state or immobilized spectra with broad parallel and perpendicular features. Whilst no firm identification is possibly based on ESR spectra, except that the trapped radical must be a high polymer, various lines of evidence lead to the conclusion that the adduct was formed from a sulphydryl radical on oxyhaemoglobin. Chloroform extracts gave the phenyl radical adduct in accord with in vitro studies. 

Reaction of the hemialdal with phenylhydrazine gave a yellow compound which resulted from the condensation of one molecule of phenylhydrazine with each dialdehyde molecule. Structure (20) or (21) was tentatively proposed for this product, since it contained one hydroxyl group and did not afford a formazan. Further studies have, however, shown that... 

Phenylhydrazine reacts typically with nitrous acid to form a-nitroso-phenylhydrazine (272), which undergoes a facile dehydration to phenyl azide when treated with acid or alkali. When Fischer discovered this reaction he postulated a cyclic structure (273) for phenyl azide, but this formulation was later abandoned in favour of the linear structure, which has now been firmly established by N-labelling studies . 

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