Acetylacetone Acetylation

Synonyms ACAC Acetoacetone Acetylacetonate Acetyl 2-propanone Diacetylmethane Pentan-2,4-dione 2,4-Pentanedione Pentanedione-2,4... 

Synonyms ACAC Acetoacetone Acetylacetonate Acetyl 2-propanone Diacetylmethane... 

Acetoxime-O-benryl ether Acctoxime-0-methyl ether Acetylacetone Acetyl chloride Acetylene... 

Ketones with labile hydrogen atoms undergo enol acetylation on reaction with ketene. Strong acid catalysis is required. If acetone is used, isoptopenyl acetate [108-22-5] (10) is formed (82—85). Isopropenyl acetate is the starting material for the production of 2,4-pentanedione (acetylacetone) [123-54-6] (11). 

With active methylene compounds, the carbanion substitutes for the hydroxyl group of aHyl alcohol (17,20). Reaction of aHyl alcohol with acetylacetone at 85°C for 3 h yields 70% monoaHyl compound and 26% diaHyl compound. Malonic acid ester in which the hydrogen atom of its active methylene is substituted by A/-acetyl, undergoes the same substitution reaction with aHyl alcohol and subsequendy yields a-amino acid by decarboxylation (21). 

The intense reddish-brown color of the acetylacetone titanium complexes impart a yellow discoloration to white inks. This discoloration is accentuated when the inks are used to print substrates that contain phenol-based antioxidants. The phenoHc compounds react with the organic titanate to form a highly colored titanium phenolate. Replacement of 0.25 to 0.75 moles of acetylacetone with a malonic acid dialkyl ester, such as diethyl malonate, gives a titanium complex that maintains the performance advantages of the acetyl acetone titanium complexes, but which is only slightly yellow in color (505). These complexes still form highly colored titanium phenolates. 

Reaction type 3 (equation 10), where the complete hetero-l,3-diene skeleton is incorporated into the newly formed ring system, occurs with compounds having both a nucleophilic center and an electrophilic center If these two functionalities are in positions 1 and 2, various types of six-membered ring systems become accessible 4,4-Bis(trifluoromethyl)-I,3-diaza-1,3-butadienes require only room temperature to react with acetyl cyanide to yield l,4,5,6-tetrahydropynmidin-6-ones [96] Likewise, certain open-chain 1,3-diketones (acetylacetone and acetoacetates) and the heterodiene form six-membered nng systems [97] (equation 19)... 

From Table 3, it can be seen that the reactivity of acyl acetanilide, such as BAA or AAA, is higher than that of the other reductant reported from our laboratory, i.e., acetanilide (AA), N-acetyl-p-methylaniline (p-APT), acetylacetone (AcAc), and ethyl acetoacetate (EAcAc). Moreover, the promoting activities of derivatives of acetoacetanilide were affected by the ortho substituent in benzene ring, and the relative rate of polymerization Rr) decreased with the increase of the bulky ortho substituent to the redox reaction between Ce(IV) ion and substituted acetoacetanilide. 

Low yields of the 5-acetyl-l0,11-epoxy derivative 11 (R = Me) are also obtained by oxidation of 5-acetyl-5//-dibenz[/>,/]azepine (10, R = Me) with iodoxybenzene and vanadium(lll) acetylacetonate, and with iodosobenzene and iron(lll) porphyrin.220... 

Metal acetylacetonates (M-ac.ac), also known as pentanedionates, are produced by reacting metals and acetyl acetone. They have the following chemical structure ... 

The acetylacetonates are stable in air and readily soluble in organic solvents. From this standpoint, they have the advantage over the alkyls and other alkoxides, which, with the exception of the iron alkoxides, are not as easily soluble. They can be readily synthesized in the laboratory. Many are used extensively as catalysts and are readily available. They are also used in CVD in the deposition of metals such as iridium, scandium and rhenium and of compounds, such as the yttrium-barium-copper oxide complexes, used as superconductors. 1 1 PI Commercially available acetyl-acetonates are shown in Table 4.2. 

Pyrolysis of hafnium acetyl acetonate, Hf(C5H702)3, at 400-750°C or hafnium trifluoro-acetylacetonate, Hf(C5H402p3)4 at 500-550°C with helium and oxygen as carrier gases. 

The N-acetyl derivatives of 2-aminohexoses give a reaction even in the absence of acetylacetone [4]. 

Acetylacetanilid, a24 Acetyl acetate, a22 Acetylacetone, p34 A-Acetylanthranilic acid, all Acetylbenzene, a31 Acetylcyclopropane, c410 Acetylene dichloride, d228, d229... 

Acetylacetone, 7 148-149, 164 74 596-598 molecular formula, 5 712t TV-Acetylacrylamide, 7 293 Acetyl anchoring groups, 5 683t Acetylated cyclodextrin-based chiral stationary phase, 6 87 Acetylated lanolin, cosmetically useful lipid, 7 833t... 

A mixture of acetyl acetone, 1-nitronaphthalene, and naphthalene has been proposed for evaluating reversed-phase packing material [102]. This reveals the usual optimum kinetic chromatographic parameters (the naphthalene peak), the degree of activity or end-capping status of the column (the ratio of the 1-nitronaphthalene and naphthalene retention times) and trace metal activity (the shape and intensity of the acetylacetone peak). 

Acetylacetone has been prepared by the reaction of acetyl chloride with aluminum chloride followed by hydrolysis,3 and by the condensation of acetone with ethyl acetate under the influence of sodium,4 sodamide,5 and sodium ethoxide,5-6-7 and by the reaction of acetone and acetic anhydride in the presence of boron trifluoride.8... 

The barriers to acetyl group rotation in 84a to d are at least as high as in the acetylacetonate anion (Table 18), indicating a considerable delocalization of negative charge into Ac—Q—Ac. As mentioned later (Table 19), the twist angle in 84a is 73°. ... 

Now for some interesting features of the reaction, though they become fairly obvious with a little thought. First, the central methylene contains the more acidic protons (pATa 9) since it is flanked by two carbonyls, so the enolate anion formed involves this carbon (see Section 4.3.5). In other words, alkylation occurs on the central carbon of acetylacetone, not on the terminal carbons. Second, it is possible to use carbonyl compounds such as acetone as a solvent without these reacting under the reaction conditions. Acetone will have similar acidity (pATa 19) to the acetyl groups of acetylacetone, so likewise will not... 

Synonyms Acetylacetone, diacetyl methane, acetyl 2-propanone, 2,4-PD... 

Acetylacetone derivatives of bis-dithiolobenzoquinone 232 show remarkable reactivity (95M615) with cyanoacetic acid derivatives 27 in ethanol with piperidine. They proceed via symmetrical elimination of two acetyl groups and subsequent cyclization to bis-pyrano derivatives 233 (Scheme 89). 

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