Phenyl benzoate reactions

Dissolve 5 g. of phenol in 75 ml. of 10 per cent, sodium hydroxide solution contained in a wide-mouthed reagent bottle or conical flask of about 200 ml. capacity. Add 11 g. (9 ml.) of redistilled benzoyl chloride, cork the vessel securely, and shake the mixture vigorously for 15-20 minutes. At the end of this period the reaction is usually practically complete and a sohd product is obtained. Filter oflf the soUd ester with suction, break up any lumps on the filter, wash thoroughly with water and drain well. RecrystaUise the crude ester from rectified (or methylated) spirit use a quantity of hot solvent approximately twice the minimum volume required for complete solution in order to ensure that the ester does not separate until the temperature of the solution has fallen below the melting point of phenyl benzoate. Filter the hot solution, if necessary, through a hot water funnel or through a Buchner funnel preheated by the filtration of some boiling solvent. Colourless crystals of phenyl benzoate, m.p. 69°, are thus obtained. The yield is 8 g. 

The three chemical reactions in the toluene—benzoic acid process are oxidation of toluene to form benzoic acid, oxidation of benzoic acid to form phenyl benzoate, and hydrolysis of phenyl benzoate to form phenol. A typical process consists of two continuous steps (13,14). In the first step, the oxidation of toluene to benzoic acid is achieved with air and cobalt salt catalyst at a temperature between 121 and 177°C. The reactor is operated at 206 kPa gauge (2.1 kg/cm g uge) and the catalyst concentration is between 0.1 and 0.3%. The reactor effluent is distilled and the purified benzoic acid is collected. The overall yield of this process is beheved to be about 68 mol % of toluene. 

Only a few diacvl peroxides see widespread use as initiators of polymerization. The reactions of the diaroyl peroxides (36, R=aryl) will be discussed in terms of the chemistry of BPO (Scheme 3.25). The rate of p-scission of thermally generated benzoyloxy radicals is slow relative to cage escape, consequently, both benzoyloxy and phenyl radicals are important as initiating species. In solution, the only significant cage process is reformation of BPO (ca 4% at 80 °C in isooctane) II"l only minute amounts of phenyl benzoate or biphenyl are formed within the cage. Therefore, in the presence of a reactive substrate (e.g. monomer), tire production of radicals can be almost quantitative (see 3.3.2.1.3). 

The importance of the cage reaction increases according to the viscosity of the reaction medium. This contributes to a decrease in initiator efficiency with conversion. 15 1 155 Stickler and Dumont156 determined the initiator efficiency during bulk MMA polymerization at high conversions ca 80%) to be in the range 0.1-0.2 depending on the polymerization temperature. The main initiator-derived byproduct was phenyl benzoate. 

The oxidation reaction of ketones by m-chloroperbenzoic acid (49) in the solid state was found to proceed faster than in solution. For example, when a mixture of finely powdered benzophenone and two molar amounts of finely powdered 49 was kept at room temperature for 24 h, phenyl benzoate was obtained in 85 % yield (Table 7) 28). In contrast, the same reaction in chloroform for 24 h gave the same product only... 

Fersht and Kirby, 1968b. Formation of the anhydride is rate determining here. The reference reaction is that of phenyl acetate with a carboxylate anion of pK, 3.11 (see note a) y Kemp and Thibault, 1968. The reference reaction is that of RCOO- with phenyl benzoate (see note j)... 

Recently, the PER of phenyl acetate and phenyl benzoate has been studied within zeolites of the faujasite and pentasil families, which are structurally very different. [277,278] It was found that for phenyl acetatet in faujasites X and Y, the predominating product is the ortho isomer, whereas in the pentasils ZSM-5 and ZSM-11, the preferred product is the para isomer. These differences have been explained taking into account the different sizes and shapes of the cavities and channels of the two families. The faujasites are made up of channels of 8 A diameter, leading to supercages of 13 A diameter, where the reaction is expected to occur, whereas the pentasils are made up of narrow channels of 6 A diameter. In the X and Y faujasites, the ortho position would be favored due to the restricted mobility, whereas in the channels of ZSM-5 and ZSM-11, there would be a shape limitation because the ortho isomer does not fit but the para isomer does (Table 15). With phenyl benzoate inside X or Y zeolites, the same... 

The method described is adapted from the procedures of Kym 3 and Engelhardt, Latschinoff, and Malyscheff.4 Thio-benzoic acid has been prepared by the reaction of benzoyl chloride with potassium sulfide,4 hydrogen sulfide in pyridine,6 6 and magnesium bromide hydrosulfide.7 It is formed from dibenzoyl disulfide with potassium hydrosulfide,4 potassium hydroxide,4 8 and ammonia.9 It is also formed from dibenzoyl sulfide, from phenyl benzoate, and from benzoic anhydride with alcoholic potassium hydrosulfide.4 It has been obtained from dibenzoyl sulfide and hydrogen sulfide,10 carbon oxysulfide and phenyl-magnesium bromide,11 12 dibenzyl disulfide and sodium ethoxide,13 benzyl chloride and sulfur in the presence of potassium hydroxide,14 and benzylthiosulfuric acid and alkali.18 16... 

Reaction with the ester is relatively exothermic. Sensitivity of the substrate-product to heating varies and should be considered for each particular compound. Phenyl benzoate can be methylenated at room temperature with no significant decrease in product yield. By contrast, dihydrocoumarin (Preparation B) gives no product under these conditions and must be methylenated at -78°C to obtain a good yield. For most substrates it is satisfactory to carry out reactions at 0°C. 

The aminolysis of Y-phenyl X-benzoates by piperidine in 20 mol% DMS0-H20 at 25 °C proceeded, on the basis of a curved Brpnsted-type plot, via a zwitterionic tetrahedral intermediate with a change in the RDS the curvature centre of the plots was at p Ka = 6.4 regardless of the electronic nature of the substituent X in thebenzoyl moiety 27 The rates of aminolysis of a series of Y-phenyl benzoates by acylic secondary amines were compared with new results for similar reactions with Y-phenyl diphenylphosphi-nates (discussed further in the section Phosphates and Phosphinates). The results showed that the C=0 compounds were more reactive than the P=0 compounds 28... 

The rates of aminolysis of Y-phenyl diphenylphosphinates (39) (Scheme 14) by a series of alicyclic secondary amines were determined in 20 mol% DMS0-H20 at 25 °C. The phosphinates were less reactive than the corresponding Y-phenyl benzoates (the rates of which had been reported earlier). The reactions of 2,4-dinitrophenyl diphenylphosphinate [39 Y = 2,4-(N02)2l with alicyclic secondary amines resulted in a linear Br0nsted-type plot, whereas the corresponding reactions of 2,4-dinitrophenyl... 

Ramamurthy and coworkers studied the photo-Fries rearrangement of phenyl acetate and phenyl benzoate and photo-Claisen rearrangement of allyl phenyl ether (Fig. 34) included in two types of zeolite (faujasites X and Y and pen-tasils ZSM-5 andZSM-11) [192], The photolysis was performed with the zeolite slurry in either hexane or iso-octane. One of the most remarkable observations is that the product distribution is altered within zeolites from that in isotropic solvent. Furthermore, while in solution, nearly a 1 1 mixture of ortho and para isomers 40 and 41 (Fig. 34) was obtained, within zeolites one is able to direct the photoreaction selectively toward either the ortho or the para products by conducting the reaction either within faujasites or pentasils, respectively (Fig. 34). 

Figure 34 Photo-Fries rearrangement of phenyl acetate and phenyl benzoate, and photo-Claisen reaction of allyl phenyl ether in solution and within zeolites.

Decomposition of Aromatic Acyl Peroxides. The decomposition of aromatic acyl peroxides in liquid aromatic compounds is similar to the decomposition of nitrosoacetylarylamines and appears to involve the intermediate formation of free radicals. When dibenzoyl peroxide is heated in benzene, biphenyl, benzoic acid, and small amounts of phenyl benzoate, p-terphenyl, and quaterphenyl are produced. 4 That the second component enters into the reaction is shown by the formation of 4-chlorobiphenyl from the decomposition of di-p-chlorobenzoyl peroxide in benzene 84 and of dibenzoyl peroxide in-chlorobenzene 86... 

The toluene-benzoic acid process involves three chemical reactions (1) oxidation of toluene to form benzoic acid, (2) oxidation of benzoic acid to form phenyl benzoate, and (3) hydrolysis of phenyl benzoate to form phenol. 

Zeolites H-BEA and H-Y were found to be the most active catalysts, however all catalysts readily form the phenyl benzoate (Table 4.1). In the conditions of the reaction, the formation of phenyl benzoate (PB) occurs rapidly via O-acylation of phenol. Direct C-alkylation of phenol with benzoic anhydride (B) and Fries rearrangement of phenyl benzoate results in the formation of 2- and 4-hydroxy-benzophenones (2-HPB and 4-HPB) (Scheme 4.3). 

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