Chlorides benzyl

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 

Toxicity Benzyl chloride is a severe irritant to the eyes and respiratory tract. Contact with skin may cause dermatitis, and liquid contact with the eyes produces severe irritation and may cause corneal injury.116119 Benzyl chloride is a potential agent known to cause pulmonary edema in animals and humans. Experimental studies have shown development of sarcoma in animals.1193 It is, therefore, important that workers be instructed to use and handle this chemical under proper management. 

Uses Chlorodiphenyls are used in combination with chlorinated naphthalenes, which are stable, thermoplastic, nonflammable, and are used in electric cables and wires in the production of electric condensers, additives for extreme pressure lubricants, and as a coating in foundry. Chlorodiphenyls are widely used in the manufacture of herbicides, lacquers, paper, plasticizers, resins, rubbers, textiles, wood preservatives, and electric equipments. 

Uses Chlorobenzene is used as a solvent and an intermediate in dyestuffs. o-Dichlorobenzene is used as a solvent, fumigant, insecticide, and chemical intermediate. Paradichlorobenzene is used as an insecticide, chemical intermediate, disinfectant, and moth-preventive agent. 

Toxicity On exposure, chlorobenzenes are known to cause irritation to the skin, conjunctiva, and mucous membranes of upper respiratory tract. Prolonged and repeated exposure with liquid chlorobenzene causes skin burns. Acute exposure to chlorobenzenes causes drowsiness, incoordination, gait disturbances, and unconsciousness. In view of this, workers are advised to handle the chemical with proper protective clothing and under qualified supervision.122123 

To avoid nuclear chlorination due to Friedel-Crafts catalysis by iron contaminants, benzyl chloride production is carried out in vessels made from pure nickel, or in enamel or borosilicate glass apparatus. The chain reaction takes place with photochemically-produced chlorine radicals, using mercury arc lamps the reaction temperature ranges from 80 to 160 °C. The process is carried out with a chlorine deficiency, so that a high yield of benzyl chloride is achieved with low conversion. The reaction mixture is separated by distillation. 

The most important product from benzyl chloride, production of which was 

0001 in the USA in 1985, is butyl benzyl phthalate, which is manufactured by the reaction of monosodium butyl phthalate with benzyl chloride. Butyl benzyl phthalate is used as a plasticizer in the manufacture of PVC-plastics. 

Benzyl alcohol is the second most important product from benzyl chloride. Stanislao Cannizzaro deduced its structure in 1853 from the reaction of benzaldehyde with potassium hydroxide. 

Benzyl alcohol is obtained in a 70% yield from benzyl chloride and soda solution at 90 °C in a reaction lasting several hours. The reaction product is separated by distillation. Dibenzyl ether, a by-product, is used as a plasticizer. 

Eaglstein WH Allergic contact dermatitis to benzoyl peroxide—report of cases. Arch Dermatol 97 527, 1968 

Chemical Safety Data Sheet SD-81, Benzoyl Peroxide, pp 3-4, 10. Washington, DC, MCA, Inc, 1960 

National Institute for Occupational Safety and Health Criteria for a Recommended Standard. .. Occupational Exposure to Benzoyl Peroxide. DHEW (NIOSH) Pub 77-166, 117pp. Washington, DC, US Covernment Printing Office, June 1977 

lARC Monographs on the Evaluation of the Carcinogenic Risks of Chemicals to Humans, Vol 36, Allyl compounds, aldehydes, epoxides and peroxides, pp 267-283. Lyon, International Agency for Research on Cancer, 1985 

Reiners JJ Jr et al Murine susceptibility to two-stage skin carcinogenesis is influenced by the agent used for promotion. Carcinogenesis 5 301-307, 1984 

Propcr/ins.--------Cdoloui le.s.s licpiid with a faint aioinatu smell  

Refractive liquid with unpleasant, irritating odor bp, 179°C.  

Insoluble in water miscible with alcohol, chloroform, and ether.1 

The vapor irritates the respiratory system, the skin, and eyes. It is a lachrymator. The liquid burns the skin. Swallowing would cause severe internal irritation and damage.3 Large doses can cause central nervous system depression.1 Avoid breathing vapor. Prevent contact with skin and eyes.3 TLV-TWA 1 ppm (5.2 mg/m3).4 

Wear eye protection, laboratory coat, and nitrile rubber gloves. Depending on the size of the spill, breathing apparatus may be required. Cover the spill with a 1 1 1 mixture by weight of sodium carbonate or calcium carbonate, clay cat litter (bentonite), and sand. When the benzyl chloride has been absorbed, scoop the mixture into a plastic container and package for disposal by burning. Wash site of spillage with soap and water.3,5,6 

Package Lots. Place in a separate, labeled container for recycling or disposal by burning. Dissolve the compound in a flammable solvent and burn in furnace equipped with afterburner and scrubber.6,7 

Freesing point Molecular weight Refractive index N  

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Hammen equation A correlation between the structure and reactivity in the side chain derivatives of aromatic compounds. Its derivation follows from many comparisons between rate constants for various reactions and the equilibrium constants for other reactions, or other functions of molecules which can be measured (e g. the i.r. carbonyl group stretching frequency). For example the dissociation constants of a series of para substituted (O2N —, MeO —, Cl —, etc.) benzoic acids correlate with the rate constant k for the alkaline hydrolysis of para substituted benzyl chlorides. If log Kq is plotted against log k, the data fall on a straight line. Similar results are obtained for meta substituted derivatives but not for orthosubstituted derivatives. 

Thiourea, unlike urea, readily reacts in the tautomeric form (I) in the presence of suitable reagents, particularly alkyl halides thus benzyl chloride reacts with... 

Add in turn benzyl chloride (8 3 g., 8 o ml.) and powdered thiourea (5 gm.) to 10 ml. of 95% ethanol in a 100 ml. flask fitted with a reflux condenser. Warm the mixture on the water-bath with gentle shaking until the reaction occurs and the effervescence subsides then boil the mixture under reflux for 30 minutes. Cool the clear solution in ice-water, filter off the crystalline deposit of the benzylthiouronium chloride at the pump, wash it with ice-cold ethyl acetate, and dry in a desiccator. Yield, 11-12 g., m.p. 170-174°. The white product is sufficiently pure for use as a reagent. It is very soluble in cold water and ethanol, but can be recrystallised by adding ethanol dropwise to a boiling suspension in ethyl acetate or acetone until a clear solution is just obtained, and then rapidly cooling. 

Benzoic Acid, CeHgCOOH, from Benzyl Chloride, CeHaCH.Cl. 

In the following preparation, the oxidation of benzyl chloride instead of toluene is therefore given in order to reduce the time required. It should be borne in mind, however, that the procedure is othenvise independent of the nature of the side chain. 

Required Anhydrous sodium carbonate, 5 g. potassium permanganate, 10 g. benzyl chloride, 5 ml. sodium sulphite, ca. 20 g. 

In the example given below, phenylarsonic acid is reduced to dichlorophenyh arsine, Ccll jAsCl. This compound when added to aqueous sodium hydroxide and treated with benzyl chloride gives benzylphenylarsinic acid, which is readily isolated from solution. 

Methyl iodide, ethyl bromide and iodide, higher alpihatic halides chloroform, iodoform, carbon tetrachloride chlorobenzene, bromobenzene, iodobenzene benzyl chloride. 

Thiourea. Boil in ethanolic solution with benzyl chloride to prepare the crystalline benzylthiouronium chloride, m.p. lyo i 74" (P- 126). 

Alkaline permanganate. Heat under reflux i g. of i,2 naph thoquinone, 50 ml. of saturated aqueous KMn04 solution and 2 g. of anhydrous NajCO for 30 minutes. Then proceed as for oxidation of benzyl chloride (p. 393). 1,2-Naphthoquinone gives phthalic acid, m.p. 195°. Phenanthraquinone gives diphenic acid, HOOC CeH CeH COOH, m.p. 229°. 

Chlorobenzene, CjHjCl, bromobenzene, CgHgBr, and iodobenzene possess aromatic odours. Benzyl chloride, CgHjCHgCl, has a sharp irritating odour and is lachrymatory. 

Ethyl bromide and ethyl iodide behave similarly. Benzyl chloride gives a faint precipitate in the cold, but the precipitation is complete on gentle warming. 

Similar results are obtained with methyl iodide, ethyl bromide, ethyl iodide, iodoform, carbon tetrachloride, and benzyl chloride. 

Bromobenzene, iodobenzene and benzyl chloride behave somewhat similarly. The />-nitro-derivatives of the first two compounds frequently crystallise out even before pouring into water p-nitrobenzyl chloride usually remains as an oil for several minutes before solidifying. 

Formation of 2 naphthyl ethers. Alkyl halides and aryl-alkyl halides (e.g. benzyl chloride) are converted into 2-naphthyl ethers thus ... 

Heat together under reflux 1 g. of 2-naphthol, 3 ml. of 10% NaOH solution and 0 5 ml. of the halide (e.g. benzyl chloride) for 30 minutes. Cool, shake w ith about 10 ml, of water and filter off the solid ether. Recrystallise from ethanol m.p. 101 5 ... 

I. Oxidation to benzoic acid. Boil a mixture of i ml. of benzyl chloride, 50 ml. of saturated aqueous KMn04 solution and 2 g. of anhydrous Na.jCOj under reflux for 30 minutes. Acidify with cone. HCl and then add 25% Na SOj solution until the brown precipitate of MnOj has dissolved. On cooling, benzoic acid crystallises out. Filter through a small Buchner funnel, wash with water and identify (P 347) When recrystallised from water, benzoic acid has m.p. 121 . 

Oxidation, (a) Oxidise 1 g. of styrene with KMn04 and NajCOj (for details see oxidation of benzyl chloride, p. 391). Benzoic acid, m.p. 121 is obtained. Stilbene similarly gives benzoic acid, but requires longer heating—about 1 hour. 

Pungent odour. Formic acid, acetic acid, acetyl chloride, acetic anhydride, benzoyl chloride, benzyl chloride, pyridine. Benzoquinone (when warmed with water). 

By-products are formed in both preparations thus in the former, anthracene, and o- and p-dibenzylbenzenes are present in the fraction of high boiling point. Diphenylmethane is more conveniently obtained by the interaction of benzyl chloride and benzene in the presence of aluminium amalgam ... 

Prepare a solution of benzyl magnesium chloride in a 2-litre three-necked flask from 24-3 g. of magnesium turnings, 600 ml. of sodium-dried ether and 126-5 g. (115 ml.) of redistilled benzyl chloride follow the experimental details given under n-Propylbenzene (Section IV,7). Cool the flask in running water or in ice water. Place a solution of 456 g. of n-butyl-p-toluenesulphonate (Section IV,198) in about twice its volume of anhydrous ether in the dropping funnel, and add it slowly with stirring, at such a rate that the ether just boils a white solid soon forms. The addition is complete after about 2 hours. Pour the reaction product... 

In the absence of catalysts, toluene when treated with chlorine (or bromine) at the boiling point, preferably with exposure to sunlight or other bright light source, undergoes halogenation in the side chain. The entrance of the first chlorine atom, for example, proceeds at a much faster rate than the entrance of the second chlorine atom so that in practice the major portion of the toluene is converted into benzyl chloride before appreciable chlorination of benzyl chloride occurs ... 

Transfer the reaction mixture to a Claisen flask and distil vmder atmospheric pressure imtil the temperature reaches 135-140° (3). Distil the residue under diminished pressure and coUeot the benzyl chloride at 64—69°/12 mm. The latter upon redistillation boils largely at 63- 65°/12 mm. The yield of benzyl chloride is about 100 g. 

The benzyl chloride may also be isolated by distillation under atmospheric pressure. The material boiling between 165° and 185° is collected and redistilled the final product is collected at 178-182° (pure benzyl chloride has b.p. 179°). The resulting benzyl chloride is, however, of lower purity unless an efficient fractionating column is used. 

Method 2. In a 500-ml. rovmd-bottomed flask, fitted with an efficient reflux condenser, place 92 g, (106 ml.) of toluene, 68 g. (41 ml.) of redistilled sulphuryl cldoride and 1 g, of dibenzoyl peroxide (Section IV,196). Reflux gently, when a vigorous reaction takes place the reaction is complete in 30 minutes. Isolate the benzyl chloride as described in Method 1. The yield is 50 g. 

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