Industrial preparation benzyl alcohol

The NF and reagent grades are employed in the pharmaceutical industry which makes use of benzyl alcohol s local anesthetic, antiseptic, and solvent properties (17—20). It also finds use in cough symps and drops ophthalmic solutions bum, dental (21), and insect repeUant solutions and ointments and dermatological aerosol sprays. It is used in nail lacquers and as a color developer in hair dyes by the cosmetics industry (22), and in acne treatment preparations (23). 

Ben y/benzoate, [120-51-4], C6H5COOCH2C6HB, mp, 21°C, df, 1.118 bp, 323—324°C at 101.3 kPa n 1, 1.5681. This is a colorless, oily liquid with a faint, pleasant aromatic odor and a sharp, burning taste. It occurs naturally in Pem and Tolu balsams, is sparingly volatile with steam, and is insoluble in water. Benzyl benzoate is prepared commercially by the direct esterification of benzoic acid and benzyl alcohol or by reaction of benzyl chloride and sodium benzoate. The pleasant odor of benzyl benzoate, like other benzoic esters, has long been utilized in the perfume industry, where it is employed as a solvent for synthetic musks and as a fixative. It has also been used in confectionery and chewing gum flavors. 

The pharmaceutical industry makes use of benzyl alcohol s local anesthetic, antiseptic, and solvent properties. It is used in nail lacquers and as a color developer in hair dyes by the cosmetics industry, and in acne treatment preparations. 

They are both chrysanthemic acid esters of (5-benzylfuran-3-yl)methanol (Elliott alcohol, 1) [15]. Patented methods [16] for the industrial preparation of Elliotf s alcohol are demanding or such as to be hardly exploited in industrial-scale plants. For instance, in one of these methods [17] (5-benzyl-3-furyl)methanol is obtained by a sequence of Claisen condensation of benzyl cyanide and a dialkyl succinate, hydrolysis, esterification, protection of the ketone group, formylation, cyclization to 5-benzyl-3-furfuryl ester and reduction to alcohol with lithium aluminium hydride. 

Chlorination of toluene under radical conditions (either through the use of an initiator or by photolysis) gives a mixture of mono-, di- and trichlorotoluene. In practice in the perfumery industry, the reaction is run with an excess of toluene present, which means that benzyl chloride is the major product. A little benzal chloride is produced and can be separated and hydrolysed to give benzaldehyde. The major use of benzyl chloride is in the production of benzyl alcohol and its esters. The alcohol is produced by hydrolysis of the chloride. The esters can be prepared by esterification of the alcohol, but it is better economically to prepare... 

Benzyl alcohol is listed in the EC positive list of preservatives for cosmetic products (maximum concentration for application 10.000 mg/litre) as a preservative it may be useful also in pharmaceutical preparations. Percentage of use in US cosmetic formulations 0.32%. The activity of benzyl alcohol is not very much affected by the pH and the composition of the medium to be protected. As an auxiliary solvent with antimicrobial efficacy benzyl alcohol is used in preservative compositions for industrial fluids (Paulus et al., 1970a). A well-known preservative for cosmetics and industrial fluids is benzyl alcohol mono(poly)hemiformal (Paulus, 1976) which is a formaldehyde releasing compound and therefore listed under 3.1.2. 

The hydration of C-C multiple bonds is a reaction with prevalent industrial interest due to the usefulness of the products as chemical intermediates. The wool-Pd complex is an economical and highly active catalyst for hydration of olefins. It is very stable and can be reused several times without any remarkable change in the catalytic activity [73, 74]. In particular, to convert alkenes to the corresponding alcohols in excellent enantioselectivity, a new biopolymer-metal complex constituted of wool-supported palladium-iron or palladium-cobalt was prepared and used, such as allylamine to amino-2-propanoI, acrylonitrile to lactonitrile and unsaturated acids to a-hydroxycarboxylic acids [75-77]. The same catalytic system was also used for hydration of substituted styrenes to produce chiral benzyl alcohols. The simple and cleaner procedure, mild reaction conditions, high stability and recovery rate of catalyst made these catalytic systems an attractive and useful alternative to the existing methods (Scheme 37). 

Hydroxycarbonylation and alkoxycarbonylation of alkenes catalyzed by metal catalyst have been studied for the synthesis of acids, esters, and related derivatives. Palladium systems in particular have been popular and their use in hydroxycarbonylation and alkoxycarbonylation reactions has been reviewed.625,626 The catalysts were mainly designed for the carbonylation of alkenes in the presence of alcohols in order to prepare carboxylic esters, but they also work well for synthesizing carboxylic acids or anhydrides.137 627 They have also been used as catalysts in many other carbonyl-based processes that are of interest to industry. The hydroxycarbonylation of butadiene, the dicarboxylation of alkenes, the carbonylation of alkenes, the carbonylation of benzyl- and aryl-halide compounds, and oxidative carbonylations have been reviewed.6 8 The Pd-catalyzed hydroxycarbonylation of alkenes has attracted considerable interest in recent years as a way of obtaining carboxylic acids. In general, in acidic media, palladium salts in the presence of mono- or bidentate phosphines afford a mixture of linear and branched acids (see Scheme 9). 

Brombenzyl cyanide was first prepared by Riener in 1881 by hrom-inating phenyl cyanide, and its manufacture in industry was commenced n 1914. Industrially, brombenzyl cyanide is prepared in three steals, as follows (1) chlorination of toluene to form benzyl chloride (2) the conversion of benzyl chloride to benzyl cyanide by the action of sodium cyanide in alcoholic solution (3) the bromination of the benzyl cyanide with bromine vapor in the presence of sunlight. 

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