Acetylacetone, benzoylation

The reduction of pertechnetate with concentrated hydrochloric acid finally yields the tetravalent state, and no further reduction to the tervalent state takes place. Therefore, the tervalent technetium complex has usually been synthesized by the reduction of pertechnetate with an appropriate reductant in the presence of the desired ligand. Recently, the synthesis of tervalent technetium complexes with a new starting complex, hexakis(thiourea)technetium(III) chloride or chloropentakis(thiourea)technetium(III) chloride, has been developed. Thus, tris(P-diketonato)technetium(III) complexes (P-diketone acetylacetone, benzoyl-acetone, and 2-thenoyltrifluoroacetone) were synthesized by the ligand substitution reaction on refluxing [TcCl(tu)5]Cl2 with the desired P-diketone in methanol [28]. 

Diketones. Beta-diketones such as acetylacetone, benzoyl-acetone, and isopropyltropolone are well known for their applications in analytical extraction of actinides. These compounds are weak acids due to tautomerization thus they can act as cation exchange extractants. Trivalent actinide [M(III)] extraction by the reagent (HA) at low aqueous acid concentration where the compound behaves both as cation exchanger and coordinator probably follows the reaction... 

The mercaptals obtained by the acid catalyzed reaction of J3-ketoesters, e.g., ethyl acetoacetate, with methyl thioglycolate (73) undergo the Dieckmann cyclization with alcoholic potassium hydroxide at lower temperatures to give ethyl 3-hydroxy-5-methyl-2-thiophenecarboxylate (74) in 75% yield. ° Besides ethyl acetoacetate, ethyl a-ethylacetoacetate, ethyl benzoyl acetate, and ethyl cyclopentanonecarboxylate were also used in this reaction/ It is claimed that /8-diketones, hydroxy- or alkoxy-methyleneketones, or /8-ketoaldehyde acetals also can be used in this reaction. From acetylacetone and thioglycolic acid, 3,5-dimethyl-2-thiophenecarboxyl-ic acid is obtained. ... 

Fig. 4.6 Distribution ratios calculated by Eq. (4.22) for acetylacetone (HAA) benzoyl-acetone (HBA) bezoyltrifluoroacetone (HBTFA) and oxine (8-hydroxyquinoline, HOQ), in the system 0.1 M NaC104 /CCE, using the following constants. (From Refs. 

Group VI Donors. Oxygen donor ligands. A series of unsymmetrical tris-(P-diketonato)M " complexes (17) has been investigated in order to establish CIS—trans isomer distributions, and relative rates of isomerization. Included in this study was the preparation and separation of the geometric isomers of [Ru(tfac)3] and [Ru(bzac)3] (tfac = trifluoroacetylacetone, bzac = benzoyl-acetylacetone). In weakly polar media, the trans-isomer of [Ru(tfac)3] was found to be more stable, whereas the isomer distribution of similar complexes with R, R = alkyl or Ph, is statistical. ... 

Rhodium acetylacetonate differed considerably from the other metal chelates in the acetylation reaction (26). Under the same conditions that had given extensive acetylation of the cobalt and chromium acetylacetonates, the rhodium chelate reacted very slowly and formed only a small amount of the monoacetylated compound (XX). Fortunately, the hydrolytic stability of rhodium acetylacetonate is such that the Friedel-Crafts reaction can be carried out under vigorous conditions that would rapidly degrade the chromium and cobalt chelates. Thus treatment of rhodium acetylacetonate with acetyl chloride and aluminum chloride in dichloroethane afforded the mono- and diacetylated chelates (XX and XXI). No triacetylated chelate was isolated from this reaction. In a similar manner butyryl-and benzoyl-substituted rhodium chelates (XXIII and XXIV) have been prepared. These and other experiments indicate that the rhodium acetylacetonate ring is less reactive than the cobalt or chromium rings. 

Several polydentate SBs may act as binucleating ligands see Section 33.5.12.1. Only a few miscellaneous polydentate SBs will be included here. A complex with the SB obtained in the reaction of two moles of benzoyl hydrazide with acetylacetone had v(V=0) = 995 cm 1, Pea =1.7BM and was monomeric square pyramidal (117).792 A few complexes with the ethylenediamine derivatives of 2,2 -dihydroxychalcones (118) were prepared in ethanol.793 The stoichiometry is 1 1 and the atoms involved in the coordination were two deprotonated oxygens and two nitrogen atoms. v(V—O) (970-985 cm-1) and f4 (1.73-1.83 BM) suggest a monomer however, molecular weights in nitrobenzene suggest a dimer. 

Among other organic compounds of vanadium the following are known Vanadous acetate,8 vanadous acetylacetonate, vanadous benzoyl-acetonatef vanadous carbamides,10 vanadyl acetonates,11 vanadyl acetate,... 

Pinacolone, o-(diphenylphosphino)benzoyl-coordination chemistry, 401 Piperidine, IV-hydroxy-metal complexes, 797 pA a values azole ligands, 77 Plant roots amino acids, 962 carboxylic acids, 962 Plastocyanin copper binding site, 557 copper(II) complexes, 772 copper(II) site in, 770 Platinum, dichlorobis(benzonitrile)-IR spectrum, 264 Platinum, cis-dichlorodianunine-antitumor activity, 34, 979 Platinum, ethylenebis(triphenylphosphine)-reactions with 5,6-dimethyl-2,l,3-benzothiadiazole, 194 Platinum blue formation, 265 Platinum complexes acetylacetone reactions, 380 amides, 491 amidines... 

Selenium acetylacetone may be converted into selenium benzoyl-acetone by dissolving it in a warm solution of benzoylacetone in chloroform in the presence of a trace of sodium hydroxide, the resulting selenium frisbenzoylacetone being converted into selenium benzoylacetone by boiling with alcohol. 

Chelating extractants such as beta-diketones, tropolones, hydroxyoximes, and 8-hydroxyquinolines (Figure 2.1), have been used extensively for the extraction of actinide ions from moderate to weakly acidic solutions (15-17). Beta-diketones such as acetylacetone (acac), HTTA, benzoyl trifluoroacetone (BTFA), and dibenzoyl-methane (HDBM) have been commonly used for the separation of actinide ions. The extraction mechanism involved formation of the enol form of the beta-diketone prior to complexation and extraction of the metal ion (Figure 2.2). 

Moreover, 3-benzoyl-2,4-pentanedione (215) is obtained when benzoylchloride is employed to the acetylacetone derivate i94143) whereas the reaction with benzaldehyde results a mixture of 3-benzylidene-2,4-pentanedione (213) and 3-[a-hydro-xy-benzyl]-2,4-pentanedione (214)143 ... 

This work was followed by a more detailed study including determination of quantum yields and lifetimes for the Ybm /i-dikctonates formed with fluorinated benzoyl (48c-j, fig. 41) and thienyl (49a-e) derivatives of acetylacetonate and for their corresponding ternary complexes with phen (Meshkova et al., 1999 Tsvirko et al., 1999). Complexation of 1,10-phenanthroline induces 3- to 6-fold increases in quantum yields, which amount to 0.11-0.35% for the tris complexes while they reach 0.65-1.20% for the ternary complexes (fig. 46). A par-... 

A binder was obtained from an epoxynovolak resin, BPA/DC, BMI, dicyclopenta-diene, Zn acetate and dicumyl peroxide [94]. In a similar composition, BPA/DC prepolymer was used as curing and cyclotrimerization initiators and catalysts, catechol, triethylenediamine, Zn acetate and benzoyl peroxide are mentioned [95], Other compositions contain A1 acetylacetonate and a silicone resin [96], p-toluenesulfonic acid monohydrate and Zn octoate (for rapid curing) [97], or dicumyl peroxide and Zn octoate [98]. 

Inner chelates (uncharged chelates) are formed when metal ions react with bifunctional ligands, such as dithizone (formula 1.1), 8-hydroxyquinoline [14] (formula 1.2), dithiocarbamates (formulae 1.3 and 1.4), ethyl xanthates [15,16], cupferron (formula 1.5), BPHA (N-benzoyl-N-phenylhydroxylamine) [17,18], acetylacetone (formula 1.6) and thenoyltrifluoroacetone (HTTA) (formula 1.7) [19,20]. 

The decomposition rate constant kd for pure benzoyl peroxide in styrene polymerizations is 1.33x10" s at 90°C, while that for the benzoyl peroxide-N,N-diethylaniline redox system is 1.25x10" L/mol-s at 60°C and 2.29x10" L/mol-s at 30°C [15]. The redox system thus has a much larger decomposition rate. Peroxide decomposition is also accelerated in the presence of transition metal ion complexes such as copper (II) acetylacetonate and ammonium salts [17,18]. 

The acylation of the metal chelates of /3-diketones has been studied quite extensively. In early work on the benzoylation of acetylacetone chelates, C-acylation as well as O-acylation was reported to occur (47,156), and a recent study on the benzoylation of dibenzoylmethane chelates confirmed this (153). In an investigation of the reaction of m- or p-nitro-benzoyl chloride with the copper(II) chelate of acetylacetone, it was found that on shaking the reactants together in CHC13 for 12-24 hours at room temperature a triketone was obtained together with a precipitate of cupric chloride. The triketone could be converted to a /3-diketone by treatment with aqueous ammonia followed by acidification with HC1 (20) ... 

Naphthodiazepines have been obtained from diaminonaphthalenes. 1,2-Diaminonaphthalene condensed with acetylacetone,23-28 benzoyl-acetone28 or dibenzoylmethane28 in methanol-acetic acid, and addition of acid gave salts of the naphthodiazepines (14). In the case of benzoylacetone... 

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