Phenyl esters of benzoic acid

Perfumes, Flavors, Cosmetics, and Soap. Many naturally occurring esters in essential oils and some synthetic esters are important fragrance and flavor compounds (61,62). They are used in perfumes, flavors, cosmetics, soaps, detergents, and air fresheners. Benzyl, butyl, ethyl, methyl, and phenyl esters of benzoic acid are used as flavors, perfumes, and food preservatives. Glyceryl 4-aminobenzoate [136-44-7] and 2-ethyUiexyl 4-dimethylaminobenzoate [21245-02-3] are used in cosmetic sunscreen preparations. Alkyl esters of 4-hydroxybenzoic acid, called parabens, have been used under various names for fungus infections of the skin, and as preservatives in lotions and creams (101). Soap and cosmetic fragrances use large amounts of amyl and benzyl saHcylate. Benzyl saHcylate [118-58-1] is also used in deodorant sprays. 2-Ethylhexyl saHcylate [118-60-5] and 2-ethylhexyl 4-methoxycinnamate [5466-77-3] are used in sunscreen formulations (102). 

Reaction of phenol derivatives with acyl chlorides in acidic conditions may result in O-acylation or C-acylation, either directly or via a Fries rearrangement. Studies of acylations in acetonitrile using trifluoromethanesulfonic acid (trifllc acid) have shown that O-acylation is favoured at a low acid concentration, while a high acid concentration favours C-acylation. It has also been shown that A-hydroxysuccinimidyl and phenyl esters of benzoic acids are activated by triflic acid and can be used to acylate electron-rich arenes such as ferrocene or pyrene the reactive acylating intermediate is likely to be an acyl triflate or its protonated form. In a polyphosphoric acid medium, the rearrangement of 1,5- 1,8- and 9,10-diacetylanthracenes leads to the formation of the ring-closed product (56). DFT calculations support the conclusion that the reaction involves the intermediacy of 1,9-diacetylanthracene formed under kinetic rather than under thermodynamic control. ... 

B, Preparation of S olid Derivatives, such as a)Esters of benzoic acid and nitrobenzoic acids (p331) b)Alkyl N-Arylcarbamates (Phenyl- and a-Naph-thy lure thanes) (p331) and e)Bis (triphenylmethyl) Esters (p332)... 

A reaction of 4-nitro-l,2-phenylendiamine with benzotrichloride in the presence of sodium methylate [367] has been described. In this case 2-phenyl-5(6)-nitroben-zimidazole is obtained without preliminary extraction of the ortho-ester of benzoic acid. Sometimes acylated polynitroanilines, with one of the groups in the orthoposition to the amino group, are used as the initial products. On partial reduction of such compounds the cyclization to benzimidazoles takes place [85, 368], For example, the reduction of 2,4-dinitroacetanilyde with ammonium sulfide has afforded 2-methyl-5(6)-nitrobenzimidazole (Scheme 2.41) [85],... 

Esters.—The esters of benzoic acid are not of special importance. The methyly ethyl, phenyl and benzyl esters are found in certain plants... 

Phenyl ketones Esters of benzoic acids lodocompounds lodocompounds Phenyl esters... 

Ethyl or longer-chain phenyl ethers, in addition, would produce an ion of m/z 94 (C6H60+ ) via McLafferty-type rearrangement [reaction (6.29)]. The ion of m/z 93 (C6H7N+) is also prodnced from ionized 2-alkyl and 4-alkylpyridines via the McLafferty rearrangement. The m/z 105 ion (CeHsCO" "), which is produced via a-cleavage, is evidence for the presence of phenyl ketones and esters and amides of benzoic acids. Esters of benzoic acids will also produce a characteristic ion of m/z 122 as a result of the McLafferty rearrangement ... 

Methyl, ethyl, n-propyl, isopropyl, n-hutyl, benzyl, cyclohexyl esters of formic, acetic, oxalic, succinic, tartaric, citric, benzoic, salicylic (and other substituted benzoic acids), phthalic and cinnamic acids phenyl esters of acetic, benzoic and salicylic acids. 

The majority of preservatives are bacteriostatic rather than bacteriocidal, and consist of both acid and nonacid types. Among the acidic types are phenol, chloro-cresol, O-phenyl phenol, alkyl esters of parahydroxybenzoic acid, benzoic acid, boric acid, and sorbic acid, and their respective salts. Therefore, the pH of solution, and the pAa of the preservative need to be carefully evaluated prior to selecting a preservative for a formulation. Neutral preservatives include chlorobutanol, benzyl alcohol, and beta-phenylethyl alcohol. Under alkaline conditions, it is generally regarded that most microbial growth is significantly retarded at these pH values, which reduces the need for a preservative. 

Actually, these considerations are confirmed by experiments 82). The systems investigated are shown in Table 8, No. 4, which are induced cholesteric polymer systems. The nematogenic host molecules of benzoic acid phenyl esters are linked via spacers of different length m (m = 3, 4, 5, 6) to the polymer backbone. The polymers are converted to polymers having a cholesteric phase by the chiral cholesteryl derivative, which is also linked to the polymer backbone (copolymer). 

A typical glucuronide of type I is benzoyl /3-D-glucuronide (R = CaH5-) and of type II phenyl /3-D-glucuronide (R = C6H5-), which are, respectively, metabolites of benzoic acid and phenol in most species. Glucuronides of types I and II are often designated ester and ether ... 

The regioselective anti-Markovnikov addition of benzoic acid to phenyl-acetylene has also been carried out with success at 111 °C in the presence of ruthenium complexes containing a tris(pyrazolyl)borate (Tp) ligand [RuCl(Tp)(cod), RuCl(Tp)(pyridine), RuCl(Tp)(N,N,Ar,AT-tetramethylethyl-enediamine )] with a stereoselectivity in favour of the (E)-enol ester isomer [22]. The o-enynyl complex Ru(Tp)[PhC=C(Ph)C=CPh](PMe/-Pr2) (C) efficiently catalyses the regioselective cyclization of a,cu-alkynoic acids to give en-docyclic enol lactones [23] (Eq. 2). 

The effect of the degree d xrlarization of the ester linkages in low-motecular-weight esters on their reactivity has been examined by studying the reaction of alcoholysis, with ceUulose, of methyl esters of benzoic, p-chloro-, p-hydroxy, p-hydroxy-, p- and o-nitrobenzoic acids, and those of phenyl-, phenoxy-, 2,4-dichlorophenoxy- and monodiloro-acetic adds. The trans-esterification reaction was carried out in non-aqueous dinrethylformamide in the presence of catalysts (sodium methylate, cadmium acetate, p-toluenesulphonic add) at 110-140° C. 

Which of the two is the cis form and which the trans form has not been determined. A third cinnamic acid, viz., iso-cinnamic acid, is also known, but the constitution of it has not been established. Cinnamic acid is found in nature in the resin storax both as the free acid and as the cinnamic alcohol ester, styrin. It is also found in Peru and Tolu balsams as the free acid and as the benzyl alcohol ester, the benzoic acid ester of benzyl alcohol being present also. Thus benzyl alcohol, benzoic acid, cinnamic alcohol and cinnamic acid are all constituents of esters present in these plant resins. Allo-cinnamic acid, the geometric isomer, is obtained from coca leaves from which the alkaloid cocaine is also obtained (p. 896). When cinnamic acid is heated with lime it loses carbon dioxide and yields the unsaturated side-chain hydrocarbon st3rrene, or phenyl ethylene, CeHs—CH = CH2. On reduction it yields first cinnamic aldehyde, found in oil of cinnamon (p. 842) and then cinnamic alcohol. Both cinnamic acid and allo-cinnamic acid yield anhydrides. 

Homopolymers. Phenylesters of benzoic acid were chosen as mesogenic groups for the synthesis of suitable monomers. The acryloyl- and the methacryloyl moieties were used as polymerizable groups. The flexible spacer was an alkyl chain or an alkyloxy chain of varying length. Thus a homologous series of p-"(2-methylpropenoyloxyalkyoxy) benzoic acid -p substituted phenyl esters 1 was prepared. The monomers were synthesized by the standard methods as follows ... 

Percolation of an ether solution of benzoic acid through a column of a macroporous AER in OH" form put the resin in benzoate form. Stirring of the resin with 4 molar equivalents of ethyl bromoacetate at room temperature produced 99% of ethyl benzoyloxyacetate as shown in equation (18). Similar displacement reactions of alkyl halides have been used to form esters from other carboxylate ions, " alkyl fluorides from phenyl sulfones from PhSO N,N ... 

CDX-026 (9.2 kg) and the cofactor NADP-Na (0.23 kg) were added to the reaction mixture and the reaction was carried out at 40-45°C under stirring for 40-45 h. At the end of the reaction, saturated NaCi soiution (4 voi) and ethyi acetate (10 voi) were added to the reaction mixture. The enzyme was fiitered at 60-70°C using a pressure nutsche. The organic phase containing the product was separated. The aqueous iayer was extracted with ethyi acetate (2 voi), and the organic phase was combined with the product layer. The combined organic phase was dried and concentrated to give the crude (S)-2-[3-2[7-chloro-2-quinolinyl]ethenyl]phenyl-3-hydroxypropyl]benzoic acid methyl ester 64. The crude product was purified by recrystallisation from 70% aqueous methanol (14 voi) to get pure product 64 as monohydrate 3 (233 kg), 97.2% yield, >99.9% ee [125,126]. 

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