Benzyl chloride, manufacture

Benzyl Chloride. Benzyl chloride is manufactured by high temperature free-radical chlorination of toluene. The yield of benzyl chloride is maximized by use of excess toluene in the feed. More than half of the benzyl chloride produced is converted by butyl benzyl phthalate by reaction with monosodium butyl phthalate. The remainder is hydrolyzed to benzyl alcohol, which is converted to ahphatic esters for use in soaps, perfume, and davors. Benzyl salicylate is used as a sunscreen in lotions and creams. By-product benzal chloride can be converted to benzaldehyde, which is also produced directiy by oxidation of toluene and as a by-product during formation of benzoic acid. By-product ben zotrichl oride is not hydrolyzed to make benzoic acid but is allowed to react with benzoic acid to yield benzoyl chloride. 

In the past benzal and benzyl chlorides were co-produced for the manufacture of benzaldehyde and benzyl alcohol, but today the vast majority of the benzaldehyde produced from benzal chloride is that which is made from recovered (by-product) material. For an historical article regarding the chlorination of toluene and the subsequent production of benzaldehyde, benzyl alcohol, and benzoic acid, see reference 4. 

Manufacture. Today benzyl alcohol is almost universally manufactured from toluene which is first chlorinated to give benzyl chloride [100-44-7]. This is then hydrolyzed to benzyl alcohol by treatment with aqueous sodium carbonate. 

Nearly all of the benzyl chloride [100-44-7], henzal chloride [98-87-3], and hen zotrichl oride /P< -(97-i manufactured is converted to other chemical intermediates or products by reactions involving the chlorine substituents of the side chain. Each of the compounds has a single primary use that consumes a large portion of the compound produced. Benzyl chloride is utilized in the manufacture of benzyl butyl phthalate, a vinyl resin plasticizer benzal chloride is hydrolyzed to benzaldehyde hen zotrichl oride is converted to benzoyl chloride. Benzyl chloride is also hydrolyzed to benzyl alcohol, which is used in the photographic industry, in perfumes (as esters), and in peptide synthesis by conversion to benzyl chloroformate [501-53-1] (see Benzyl ALCOHOL AND p-PHENETHYL ALCOHOL CARBONIC AND CARBONOCm ORIDIC ESTERS). 

Benzyl chloride is manufactured by the thermal or photochemical chlorination of toluene at 65—100°C (37). At lower temperatures the amount of ring-chlorinated by-products is increased. The chlorination is usually carried to no more than about 50% toluene conversion in order to minimize the amount of benzal chloride formed. Overall yield based on toluene is more than 90%. Various materials, including phosphoms pentachloride, have been reported to catalyze the side-chain chlorination. These compounds and others such as amides also reduce ring chlorination by complexing metallic impurities (38). 

Nearly all uses and appHcations of benzyl chloride are related to reactions of the active haUde substituent. More than two-thirds of benzyl chloride produced is used in the manufacture of benzyl butyl-phthalate, a plasticizer used extensively in vinyl flooring and other flexible poly(vinyl chloride) uses such as food packaging. Other significant uses are the manufacture of benzyl alcohol [100-51-6] and of benzyl chloride-derived quaternary ammonium compounds, each of which consumes more than 10% of the benzyl chloride produced. Smaller volume uses include the manufacture of benzyl cyanide [140-29-4], benzyl esters such as benzyl acetate [140-11-4], butyrate, cinnamate, and saUcylate, benzylamine [100-46-9], and benzyl dimethyl amine [103-83-8], and -benzylphenol [101-53-1]. In the dye industry benzyl chloride is used as an intermediate in the manufacture of triphenylmethane dyes (qv). First generation derivatives of benzyl chloride are processed further to pharmaceutical, perfume, and flavor products. 

The ring-chiorinated benzyl chlorides are used ia the preparation of quaternary ammonium salts and as iatermediates for pharmaceuticals and pesticides. p-C. orohen zyl chloride is an iatermediate ia the manufacture of the rice herbicide, Saturn ((S-4-chlorobenzyl)-N,N-diethylthiolcarbamate [28249-77-6] (75). The o- and -chlorobenzal chlorides (l-chloro-2-and 4-dich1 oromethylhenzenes) are starting materials for the manufacture of o- and p- chlo rob enz aldehyde s. 

Bendazac Chloride (1 -benzyl-1 H-indazol-3-yl)oxy] acetic acid chloride Manufacturing Process... 

Example 5.4 Benzyl acetate is used in perfumes, soaps, cosmetics and household items where it produces a fruity, jasminelike aroma, and it is used to a minor extent as a flavor. It can be manufactured by the reaction between benzyl chloride and sodium acetate in a solution of xylene in the presence of triethylamine as catalyst9. 

Side-Chain Chlorination of Toluene. Benzyl chloride, used mainly in the manufacture of plasticizers, may be prepared by the thermal or photochemical chlorination of toluene.191,192 In the thermal process chlorine is passed through toluene at 65-100°C. To minimize the formation of benzal chloride and benzotrichloride, the conversion is limited to about 50%. Since the density of the reaction mixture increases linearly with the formation of benzyl chloride,145 measurement of density is used to monitor the progress of the reaction. The overall yield based on toluene is about 90%, and the maximum conversion to benzyl chloride is above 70%. Higher yields in photochemical chlorination may be achieved. 

Bendazac chloride ([(l-benzyl-lH-indazol-3-yl)oxy]acetic acid chloride) Manufacturing Process... 

Benzoic acid also can be obtained as a by-product of the manufacture of benzaldehyde from benzal chloride or benzyl chloride. 

Benzyl alcohol is manufactured by hydrolysis of benzyl chloride. 

Still in the forties, butyl benzyl phthalate (BBP) was introduced by Monsanto Co. This ester is based on the monohydric alcohol n-butanol, but the benzyl group is derived from benzyl chloride rather then benzyl alcohol. This route was selected to make possible manufacture of pure coester which showed a better balance of properties than if made from the two alcohols. BBP was destined to make its mark in PVC, particularly in the flooring industry. 

Uses Benzyl chloride is a colorless liquid with an irritating odor. It is used in the manufacture of plastics, dyes, synthetic tannins, perfumes, resins, gasoline additives, germicides, perfumes, photographic developers, rubbers, wetting agents, drugs, and pharmaceuticals. It also is used in production of benzal chloride, benzyl alcohol, and benzaldehyde.116... 

Benzyl Chloride. The principal method for producing benzyl chloride involves the photochlorination of toluene, followed by neutralization and distillation. In 1999, 75 million lb of benzyl chloride were produced in the United States. About two-thirds was used to manufacture benzyl phthalates (mainly butyl benzyl phthalate), which are widely used as plasticizers. The other use was to make benzyl quarts. Benzyl chloride can also be used as raw material in the manufacture of benzyl alcohol, for use in photography, perfumes, and cosmetics. The production has increased considerably in Western Europe because of the greater use in solvents such as benzyl esters. But the U.S. production was stopped in 1999. 

In this chapter we discuss the mechanistic and other details of a few industrial carbonylation processes. These are carbonylation of methanol to acetic acid, methyl acetate to acetic anhydride, propyne to methyl methacrylate, and benzyl chloride to phenyl acetic acid. Both Monsanto and BASF manufacture acetic acid by methanol carbonylation, Reaction 4.1. The BASF process is older than the Monsanto process. The catalysts and the reaction conditions for the two processes are also different and are compared in the next section. Carbonylation of methyl acetate to acetic anhydride, according to reaction 4.2, is a successful industrial process that has been developed by Eastman Kodak. The carbonylation of propyne (methyl acetylene) in methanol to give methyl methacrylate has recently been commercialized by Shell. The Montedison carbonylation process for the manufacture of phenyl acetic acid from benzyl chloride is noteworthy for the clever combination of phase-transfer and organometallic catalyses. Hoechst has recently reported a novel carbonylation process for the drug ibuprofen. 

Benzyl chloride is used in the manufacture of ethylbenzylaniline and dibenzylaniline for triarylmethane dyes. 

The asymmetrical tertiary amines are used exclusively as starting materials for the manufacture of quaternary ammonium compounds, cationic and amphoteric surfactants, and amine oxides. Quaternary ammonium compounds used as bactericides and algicides are produced by the reaction of tertiary amines with benzyl chloride, methyl chloride, or dimethyl sulfate. Of these, the benzyl ammonium chloride salt is the most widely used. 

In the industrial manufacture of bromobenzyl cyanide it is preferable to commence with benzyl chloride rather than benzyl bromide. This is easily obtained by the chlorination of toluene under the influence of sunlight (see p. 129) or by the aid of a mercury vapour lamp. ... 

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. 

Manufacture of Benzaldehyde from Benzyl Chloride using Hexamine... 

In the industrial process, benzyl alcohol is normally manufactured by refluxing benzyl chloride with an alkali over a very long period ( 24 hrs). However, this process leads to significant formation of the byproduct benzyl ether [1]. Several attempts have been reported in the literature to suppress the yields of the ether. Thus, it was thought... 

Benzoic Acid, CeHs.COOH, occurs in gum-benzoin, in many resins, in the balsams of Peru and Tolu, in cranberries, in coal-tar, and in combination with glycine as hippuric acid in the urine of herbivorous animals. It may be made by the general synthetic methods which have been described. It is prepared for use in pharmacy bysublimination from gum-benzoin. It is manufactured on the large scale from toluene, and is a by-product in the preparation of benzaldehyde. Toluene is converted by direct oxidation into benzoic acid. As benzyl chloride, C6H5.CH2CI, is more readily oxidized than toluene, the latter is first treated with chlorine, and then heated with dilute nitric acid. It has been shown recently that if a mixture of air and the vapor of toluene is passed over vanadium oxide at about 400° the hydrocarbon is oxidized to benzoic acid. 

Benzaldehyde is a liquid with an agreeable odor, which boils at 179°, and has the specific gravity 1.0504 at 15°. It can be formed by oxidizing benzyl alcohol, or distilling calcium benzoate with calcium formate. It is manufactured by heating benzal chloride with milk of lime, or by oxidizing benzyl chloride with a solution of lead nitrate. It has been prepared from toluene directly by electrolytic oxidation or by oxidation with air in the presence of a catalyst. 

The phenyl acetic acid esters are highly valuable intermediates for a lot of applications. Among them they are applied to the synthesis of fragrances. The present industrial process for manufacture of phenyl acetic esters starts from benzyl chloride and uses the reactions with KCN to form benzyl cyanide and followed by hydrolytic cleavage. The drawbacks of the conventional route are multistep reaction and use of toxic cyanides. The new route is an environmentally benign alternative. 

Benzyl chloride is used in the manufacture of dyes, artificial resins, tanning agents, pharmaceuticals, plasticizers, perfumes, lubricants, and miscellaneous benyl compounds. 

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