Benzoyl compounds

In the Schotten-Baumann method of benzoylation, the hydroxyl- or amino-compound (or a salt of the latter) is dissolved or suspended in an excess of 10% aqueous sodium hydroxide solution, a small excess (about 10% more than the theoretical amount) of benzoyl chloride is then added and the mixture vigorously shaken. Benzoylation proceeds smoothly under these conditions, and the solid benzoyl compound, being insoluble in water, separates out. The sodium hydroxide then hydrolyses the excess of benzoyl chloride, giving sodium... 

When these benzoyl compounds separate in the course of the Schotten-Baumann reaction, they frequently occlude traces of unchanged benzoyl chloride, which thus escapes hydrolysis by the alkali it is advantageous there fore to recrystallise the benzoyl compounds whenever possible from ethanol or methylated spirit, since these solvents will esterify the unchanged chloride and so remove the latter from the recrystallised material. 

Benzoyl compounds are readily hydrolysed by heating with about 70 per cent, sulphuric acid (alkaline hydrolysis is very slow for anilides) ... 

It forms long thin prisms, which when melted tend to remain in the liquid condition, but when the liquid is sown with a crystal of the phenol it at once solidifies. It forms a benzoyl compound, melting at 72° to 73°. It is apparently dihydro-para-allylphenol of the constitution—... 

It yields a benzoyl compound, which crystallises in small plates melting at 49° to 50°. It also yields an acetyl derivative, boiling at 275° to 277°. 

Bromination of 4//-furo[3,2-b]indole (50) occurred at the 2-position and was assisted by prior N-benzylation with the 4-benzoyl compound a 61% yield of the 2-bromo derivative was obtained. Thus, a-attack in the furan moiety predominates (78JHC123). When the pyrazolofuran (51) was treated with one molar equivalent of bromine, a mixture of the 2-bromo... 

Yamase and Goto406 determined first- and second-order rate coefficients for the aluminium chloride-catalysed reaction of halide derivatives of benzoic acid (lO5 = F, 1.73 Cl, 4.49 Br, 4.35 I, 0.81) and phenylacetic acid (105fc2 = F, 12 Cl, 21 Br, 9 I, 6) with benzene. The maxima in the rates for the acid chloride are best accommodated by the assumption that a highly (but not completely) polarised complex takes part in the transition state. Polarisation of such a complex would be aided by electron supply, and consistently, the acetyl halides are about a hundred times as reactive as the benzoyl compounds (see p. 180, also Tables 105 and 108). 

Thus, the uranium benzoyl compound 4 is readily hydrogenated (eq.(16)) in this case, the intermediate cannot undergo 3-... 

The hydrolysis of O-acetyl compounds is usually complete in thirty minutes, that of O-benzoyl compounds in sixty minutes. Up to three hours are required for the complete hydrolysis of N-acetyl and N-benzoyl compounds. The hydrolysis may be allowed to proceed over night, using some concentrated sulphuric acid. 

The experiment can be carried out in the same way with (3-naphthol. Melting point of the benzoyl-compound 107°. 

Other oxime ether derivatives, such as semicarbazones or benzoyl compounds, hydra-zones undergo efficient aza-di-TT-methane rearrangement139 (equation 79). 

Figure 3. The correlation of carbonyl frequencies of compounds RCOX with om constants of groups X A, acetyl compounds B, benzoyl compounds (Liler, 1967 reproduced with permission from Liler, 1971c, p. 90).

A general approach to rhenium hydrazido complexes is the reaction of oxo or chloro compounds with organohydrazines as has been demonstrated in an early report with the synthesis of [Re NNC(Ph)0 Cl2(PPh3)2] (310), " the molecular structure of which was solved in 1988. A detailed study on [Re(NNR)Cl2(PPh3)2] complexes with R = COPh or phthalazine shows that the course of subsequent reactions is governed both by the nature of the donor group R responsible for chelate closure and by the type of donor ligand introduced. No simple substitution chemistry has been observed for R = phthalazine. The benzoyl compound... 

This electrochemical oxidation mediated by NHPI was applicable to benzylic carbons, allylic carbons, deprotection of acetals, oxidative cleavage of cyclic acetals and amide to afford benzoylated compounds, enones ", carbonyl compounds, -hydroxyethyl esters and imides, respectively (equations 31-35). 

These benzoyl derivatives were prepared by shaking the amino acid with excess of benzoyl chloride in the presence of sodium bicarbonate instead of in the presence of excess of alkali, i.e., by the Schotten-Baumann method, which gave poor and varying yields of the benzoyl compound. 

Methylene groups adjacent to the N atom in tertiary polycyclic amines were oxidised by RuO /aq. Na(IO )/CCl, depending on reaction conditions. Thus A -benzyl-9-azabicyclo-[l, 3, 3]-nonane yielded AT-benzoyl-9-azabicyclo-[l, 3, 3]-nonane (Fig. 5.5) and A -benzyl-l,3-dioxo-iso-quinoline gave the A -benzoyl compound, while A -benzyl-5,6-dihydro-llH-dibenz[b,e]azepine, which has exi and endocydic benzyl groups, were oxidised to the N-benzyl-6-oxo derivative [41]. 

The acylation of dibenzofuran is carried out under the usual Friedel-Crafts conditions with an acid chloride or an acid anhydride in the presence of aluminum chloride. Dibenzofuran on treatment with 2-trifluoromethane-sulfonyloxypyridine and benzoic acid in boiling trifluoroacetic acid produces the 2-benzoyl derivative in 75% yield. The species responsible for benzoyla-tion is probably a mixed anhydride of trifluoromethanesulfonic acid and benzoic acid. Dibenzofuran on treatment with 2-benzoyloxypyridine and trifluoroacetic acid also produces the 2-benzoyl compound (21%). The kinetics of the acetylation of dibenzofuran with acetyl chloride and aluminum chloride in nitroethane at 25"C have been studied. Only the 2-acetyl compound was detected by the methods used. The rate obtained is in general agreement with the studies mentioned previously. The rate of acetylation of diphenyl ether relative to toluene was 138 (+ 16), whereas that of dibenzofuran was 5.9 ( 0.3). In contrast, the benzoylation of dibenzofuran with benzoyl chloride in the presence of aluminum chloride in nitrobenzene at... 

A -Glycosylation of sulfites 55a and 55b using silylated thymine in dry conditions at 125 °C yielded a mixture of 2 -0-silylated and 2 -hydroxy-5-methyluridine derivatives 56a and 56b, and 57a and 57b, respectively (Scheme 2). Subjecting these mixtures to desilylation conditions tetrabutylammonium fluoride, methanol (TBAF, MeOH), gave 2 -hydroxy-5-methyluridine derivatives 57a and 57b. Additionally, epimer 58 was produced as a minor product (13.5%) of N-glycosylation of 5-0-benzoylated compound 55b <2005JME4276>. 

Alkylsulfanyl)- or (Arylsulfanyl)benzoyl Compounds 4 General Procedure 26... 

Acylphosphonates, e.g. (5), possess highly reactive carbonyl groups and—somewhat like trilialomethyl ketones—exhibit both ketone and carboxy character, forming oximes and adducts, and also carboxylate derivatives via C—P bond cleavage.7 Their hemiacetal derivatives have been studied by 31P-NMR in the presence of alcohols, for the representative acetyl and benzoyl compounds (5 R = Me, Ph). Equilibrium and... 

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