Lead acetate oxidation with

Lead(II) phthalocyanine can be prepared by heating lead(II) oxide with the respective phthalonitrile without solvent150-159 or in 1-chloronaphthatene.154 Addition of anhydrous lead(II) acetate to a solution of dilithium phthalocyanine in anhydrous alcohol gives a precipitate of lead phthalocyanine.59 Lead phthalocyanine can also be obtained by electrosynthesis.160... 

Lead Acetate Solution (Caution Use gloves and goggles to avoid contact with skin and eyes. Use an effective fume-removal device or other respiratory protection.) Activate 50 to 60 g of lead (II) oxide by heating it for 2.5 to 3 h in a furnace at 650° to 670° (cooled product should have a lemon color). Boil 80 g of lead acetate trihydrate and 40 g of the freshly activated lead (II) oxide with 250 g of water in a 500-mL Erlenmeyer flask provided with a reflux condenser for 45 min. Cool, filter off any residue, and dilute with recently boiled water to a density of 1.25 at 20°. Add 4 mL of water to 1 mL of the lead acetate solution, and filter. 

Lead(2+), acetate additive for Lindlar cat, 100 basic acetate, Pbj(OAc),OH catalyst for aldol type condensation, 318 Lead(4+) acetate oxidation with ... 

The so-called metaplumbates M Pb03.3H20 are made by fusing lead(IV) oxide with an excess of potassium hydroxide. 83. These compounds are actually the alkali metal salts of the hexahydroxylead(IV) anion Pb(OH) . The salts contain discrete Pb(OH) " ions analogous to the corresponding Sn(OH) of tin(IV) 4> 5. Na2Pb(OH)6 has also been made by the electrolytic oxidation of alkali hydroxide solutions of Pb(II), and also by the controlled alkali hydrolysis of lead(IV) acetate. ... 

VI.37. OXIDATION WITH LEAD TETRA-ACETATE n-BUTYL GLYOXYLATE... 

Acid Oxidation. Reactions of lead with acid and alkaUes are varied. Nitric acid, the best solvent for lead, forms lead nitrate acetic acid forms soluble lead acetate in the presence of oxygen sulfuric acid forms insoluble lead sulfate. Sulfuric acid is stored in containers with chemical or acid-grade lead. Lead dissolves slowly in HCl, but in the presence of aqueous alkaUes forms soluble plumbites and plumbates. 

Sodium thiosulfate is determined by titration with standard iodine solution (37). Sulfate and sulfite are determined together by comparison of the turbidity produced when barium chloride is added after the iodine oxidation with the turbidity produced by a known quantity of sulfate iu the same volume of solution. The absence of sulfide is iadicated when the addition of alkaline lead acetate produces no color within one minute. 

Dibenz[yellow-green colour (due to other pentacyclic impurities) has been removed by crystn from benzene or by selective oxidation with lead tetraacetate in acetic acid [Moriconi et al. J Am Chem Soc 82 3441 7960]. 

Various 2,6-di8ubstituted p-benzoquinones have been prepared by oxidation of the corresponding 2,6-disubstituted phenols with potassium nitrosodisulfonate or lead dioxide in formic acid. Oxidative coupling of 2,6-disubstituted phenols to poly-2,6-disubstituted phenylene ethers followed by treatment of the polymers in acetic acid with lead dioxide is reported to give low yields of the corresponding 2,6-disubstituted p-benzoquinones. 

A heterocyclic ring may be used in place of one of the benzene rings without loss of biologic activity. The first step in the synthesis of such an agent starts by Friedel-Crafts-like acylation rather than displacement. Thus, reaction of sulfenyl chloride, 222, with 2-aminothiazole (223) in the presence of acetic anhydride affords the sulfide, 224. The amine is then protected as the amide (225). Oxidation with hydrogen peroxide leads to the corresponding sulfone (226) hydrolysis followed by reduction of the nitro group then affords thiazosulfone (227). ... 

Even with the highly reactive dienophile cyclohepta-2,6-dien-4-ynone, generated from 1-aminocycloheptatriazol-6-(1 H)-one by lead(IV) acetate oxidation, only the adduct of benzene oxide 3 can be isolated.231... 

Benzocyclobutene-l,2-dione (11) can be condensed with benzene-1.2-diamine to provide an annulated quinoxaline (cf. Houben-Weyl, Vol. E9b/Part 2, p203), which on oxidation with hydrogen peroxide in acetic acid leads to the 1,4-diazocine derivative 12.34... 

Alkenes can also be oxidized with metallic acetates such as lead tetraacetate or thallium(III) acetate " to give bis-acetates of glycols. Oxidizing agents such as benzoquinone, Mn02, or 02, along with palladium acetate, have been used to convert conjugated dienes to l,4-diacetoxy-2-alkenes (1,4 addition). ... 

Oxidation of chalcones with TTN has been studied in detail (95, 96), and it has been shown that the products obtained depend on the amount of reagent and the solvent employed. Oxidation with 1 equivalent of TTN in methanol, methanol-chloroform, or methanol-boron trifluoride leads to acetals of the type (XXXIV) (see also Scheme 21) in yields of 20-80%. When 3 equivalents of TTN are employed, however, and aqueous glyme containing a little perchloric acid used as solvent, the products are benzils. This remarkable transformation, which proceeds in yields varying from moderate to good (40-80%), involves three distinct oxidations by TTN, and these are outlined in Scheme 22. Each individual step in this reaction sequence has been investigated in detail, with the result that useful procedures have been developed for the oxidation of both deoxybenzoins and benzoins to benzils with TTN (96). 

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