Benzoyl acetone, reaction with

Another example of nucleophilic attack of anilines at an oxygen atom has been reported by Buxton and coworkers134. The oxidation of 4-substituted /V,/V-dimethylanilines by dimethyldioxirane, 13, in acetone showed a similar qualitative trend as those for the reactions at the Mel and benzoyl peroxide reactions with a reactivity decrease in the order X = MeO > H > Cl N02. These trends suggest that the oxidation of DMAs by 13 is electrophilic. The px value of —0.89 shows similarity to the values in the reactions of DMAs with Mel (Menschutkin reaction) which has a px value of —3.30 at 35 °C in 90% aqueous acetone. While in the latter reactions the TS is thought to have developed almost a full positive charge, the reactions with 13 have much less charge development partially due to steric crowding in the TS (Scheme 17). 

Complications often arise in the use of 1,3-diketones under the above reaction conditions. This is primarily due to the lack of regioselectivity with regard to formation of the intermediate thioacetal. However, when benzoyl acetone derivatives are employed, the thioketal forms preferentially with the aromatic ketone. ... 

With unsymmetrical diketones the orientation of the reaction is again controlled by the reaction of the most reactive carbonyl group with the 5-position of the pyrimidine ring. Thus, benzoyl acetone and 6-aminouraoil gave 5-methyd-7-phenylpyrido[2,3-d]pyrimidine-2,4-(lH,3iI)-dione (71), in preference to the 5-phenyl isomer (72). ... 

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]. 

Ammonium cerium(IV) nitrate on reaction with acetone or acetophenone generates acetyl- or benzoylformonitrile oxides, respectively (99). These nitrile oxides dimerize to furoxans and give, in the presence of alkenes and alkynes, 3-acetyl- or 3-benzoyl-4,5-dihydroisoxazoles and 3-acetyl- or 3-benzoylisoxazoles, respectively the yield of the isoxazole derivatives was improved on using ammonium cerium(III) nitrate tetrahydrate-formic acid (99). 

The bicyclic tropane ring of cocaine of course presented serious synthetic difficulties. In one attempt to find an appropriate substitute for this structural unit, a piperidine was prepared that contained methyl groups at the point of attachment of the deleted ring. Condensation of acetone with ammonia affords the piperidone, 17. Isophorone (15) may well be an intermediate in this process conjugate addition of ammonia would then give the aminoketone, 16. Further aldol reaction followed by ammonolysis would afford the observed product. Hydrogenation of the piperidone (18) followed then by reaction with benzoyl chloride gives the ester, 19. Ethanolysis of the nitrile (20) affords alpha-eucaine (21), an effective, albeit somewhat toxic, local anesthetic. 

Cyclization of the diamidine 154 with acetyl- or benzoyl-acetone (153) gave l,2,4-triazolo[l,5-a]pyrimidine (156) via the formation of 155 (66CB2237 79AP1003). Alternatively, 156 can be prepared by the reaction of 153 with the diaminotriazole 157 (66CB2237) (Scheme 29). 

Aromatic esters may be used to aroylate the dianions derived from 1,3-diketones by reaction with potassium amide (60JOC538). Not only are acetyl and benzoyl acetones suitable for reaction, but alicyclic diketones and 2-hydroxyacetophenone are also acceptable. Cycliz-ation of the triketones occurs in cold sulfuric acid, presumably via the enolic form and the hemiacetal (Scheme 132). 

Reaction of the bromolactone 90, the product of photobromination of methyl tetra-0-benzoyl-/ -D-glucopyranoside, with sodium iodide in acetone affords63 2,4,6-tri-0-benzoyl-3-deoxy-D-er)y/i/r>hex-2-enono-1,5-lactone (176) in good yield (see Scheme 30). 

Methyl 4,6-0-benzylidene-3-deoxy-a-D-ribo-hexopyranoside (56) was benzoylated, debenzylidenated, and partially p-toluenesulfon-ylated to 57 this was converted into 58 by reaction with sodium iodide, followed by catalytic reduction. The methanesulfonate of 58 was converted into 59 by reaction with sodium azide in N,N-dimethylformamide, and 59 was converted into 4-azido-3,4,6-trideoxy-a-D-xylo-hexose (60) by acetolysis followed by alkaline hydrolysis. Reduction of 60 with borohydride in methanol afforded 61, which was converted into 62 by successive condensation with acetone, meth-anesulfonylation, and azide exchange. The 4,5-diazido-3,4,5,6-tetra-deoxy-l,2-0-isopropylidene-L-ara/uno-hexitol (62) was reduced with hydrogen in the presence of Raney nickel, the resultant diamine was treated with phosgene in the presence of sodium carbonate, and the product was hydrolyzed under acidic conditions to give 63. The overall yield of 63 from 56 was 4%. The next three reactions (with sodium periodate, the Wittig reaction, and catalytic reduction) were performed without characterization of the intermediate products, and gave (+)-dethiobiotin methyl ester indistinguishable from an authentic sample thereof prepared from (+)-biotin methyl ester. 

The synthesis of the triazolo-pyridine-fused 1,3-diazocine 20a was achieved starting from 56a, which by de-O-benzoylation followed by reaction with NaN3 in DMF afforded the triazolo-pyridine 57. The latter by treatment with a mixture of acetone and 2,2-dimethoxypropane in the presence of acid afforded the O-isopropylidene derivative 60. The Mitsunobu reaction led to the diazocine 19a, which, as mentioned in Section 14.05.2.5 (Scheme 2), afforded 20a in 19% overall yield (Scheme 11) <2005JME6454>. 

With unsymmetrical diketones the orientation of the reaction is again controlled by the reaction of the most reactive carbonyl group with the 5-position of the pyrimidine ring. Thus, benzoyl acetone and... 

DIACETONALCOOL (Italian) (123-42-2z) Forms explosive mixture with air above 136°F/58°C. Violent reaction with strong oxidizers. Decomposes on contact with strong acids or strong bases, forming acetone and mesityl oxide. Reacts with alkali metals, forming explosive hydrogen. Incompatible with aliphatic amines, isocyanates, acetaldehyde, benzoyl... 

Within the cage, both fcrf-alkoxy and acryloxy radicals undergo side reactions. For example, tert-butoxy radicals d ompose to form acetone and methyl radicals while benzoyloxy radicals liberate carbon dioxide to form phenyl radicals. Fink [154] has studied the decomposition of benzoyl peroxide in benzene and analyzed the products using gas chromatography and mass spectroscopy. The three products produced were biphenyl (72%), phenyl cyclohexadiene (28%), and phenyl benzoate (0.3%). Using deuterated benzoyl peroxide, it was determined that these products arose from reaction with the benzene rather than radical combination within the cage. 

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