Detection of aromatic amines using lead tetraacetate as the reagent

Summary Intense colors are immediately produced when primary, secondary and tertiary aromatic amines are reacted with lead tetraacetate in glacial acetic acid, methanol, acetonitrile, benzene or dioxane. This color reaction forms the basis of a rapid spot test for the detection of aromatic amines.

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Zusammenfassung Primäre, sekundäre und tertiäre aromatische Amine reagieren mit Bleitetraacetat in Eisessig, Methanol, Acetonitril, Benzol oder Dioxan unter sofortiger intensiver Farbbildung. Auf der Grundlage dieser Reaktion lassen sich aromatische Amine rasch auf der Tüpfelplatte nachweisen.

     

Oxidation of perfluoronaphthols by lead tetraacetate and lead dioxide

Depending on the reaction conditions, oxidation of perfluoronaphthols by Pb(OAc)₄ proceeds by two routes. Under mild conditions (20°C) oxidation leads to the products of dimerisation of perfluoronaphthoxy radicals. At a higher temperature (80°C) the reaction leads to acetoxydienones. The mechanistic aspects of oxidation of perfluoronaphthols by Pb(OAc)₄ are discussed.     

The reaction of lead tetraacetate with hydrocarbons

The free radical reaction of lead tetraacetate with hydrocarbons has been investigated. The products of these reactions are the acetate esters. The hydrogen abstracting species from lead tetraacetate is found to have a primary to secondary to tertiary selectivity of 1:27:123 based upon relative reactivities.     

Oxidation of arylacetylhydrazones of carbonyl compounds with lead tetraacetate

Oxidation of the title compounds 8, 9 with lead tetraacetate at room temperature gives a variety of products depending on the substituents on the carbonyl carbon atom. Thus, on oxidation of the aldehyde derivatives 8 1,3,4-oxadiazolo derivatives 10 are obtained in good yields. However in some cases formation of N-acetyl-N-arylacetyl-N′-benzoylhydrazines 11 is also observed, whereas oxidation of the ketone hydrazones 9 gives in good yields the 2H,5H-1,3,4-oxadiazoles 15 or substituted monoacetoxy- 17 and diacetoxyalkanes 18 . The reaction mechanisms are also discussed.     

Oxidative cyclization of some 1,3-dioximes with lead tetraacetate

Oxidation of 1,3-dioximes 1 with lead tetraacetate gives di-N-oxides of pyrazolines 4 or pyrazoles 5 or N-oxides of oxadiazines 7 as the main reaction products. The reaction mechanism is discussed.     

Kinetics of polymerization of vinyl monomers initiated by lead tetraacetate

A systematic study of the thermal polymerization of α-chloroacrylic acid and α-bromoacrylic acid in aqueous nitric acid was carried out. The effect of variation of monomer concentration lead tetraacetate concentration, hydrogen ion concentration, ionic strength, and temperature on the rate of monomer disappearance was carried out. Based on the experimental observations, suitable reaction schemes were proposed for the polymerization of the above monomers. The rate constants and the thermodynamic parameters were evaluated.     

Solid-phase reactions of lead tetraacetate with tertiary cycloalkanols and pyridine

Russian Chemical Bulletin -     

The oxidation of compounds capable of imine-enamine tautomerism with lead tetraacetate

Compounds capable of imine-enamine tautomerism react preferentially via their enamine tautomer giving a 2-acetoxyaldehyde which equilibrates with the starting imine. This derives from the extra nucleophilicity of the β-carbon of the enamine tautomer. The reaction of the imine isomer to form an aryl- or an alkylnitrenoid species is a minor pathway.     

Complex formation effects during the oxidation of cyclohexene with lead tetraacetate

The effect of complex formation between lead(IV) and trifluoroacetic or methanesulfonic acid and chloride ion in acetic acid and Freon 113 on the oxidation of cyclohexene by lead tetraacetate was investigated. As a result of the reaction the -chlorocyclohexyl esters of the corresponding acids are formed with high yields. The formation of the complexes Pb(OAc)_4–nL_n and Pb(OAc)_4–(n+1)L_nCl, where L = CF₃CO₂- or CH₃SO₃- with n=1 or 2, was demonstrated by potentiometric titration. A scheme is proposed for the oxidation of cyclohexene with the participation of unlike-ligand complexes of Pb(IV).Translated from Teoreticheskaya Eksperimental'naya Khimiya, Vol. 21, No. 5, pp. 567–572, September–October, 1985.     

The oxidative-rearrangement of nitrogen heterocycles with lead tetraacetate and t-butyl hypochlorite

Mechanisms for the lead tetraacetate and t-butyl hypochlorite oxidation of 1,4-dihydro-3(2H)-cinnolinones and 1-amino-2-indolinones are discussed. Evidence for the lack of a nitrene intermediate is given.