Hypochlorous acid preparation

Lithium Hypochlorite. Lithium hypochlorite [13840-33-0], LiOCl, is obtained from reaction of chlorine and an aqueous solution of lithium hydroxide. The soHd is usually obtained as a dry stable product containing other alkaH haHdes and sulfates (64). A product containing 35% available chlorine is used for sanitizing appHcations in swimming pools and in food preparation areas where its rapid and complete dissolution is important. The salt can also be obtained in higher purity by reaction of lithium hydroxide and hypochlorous acid (65). 

Perchlorates. Historically, perchlorates have been produced by a three-step process (/) electrochemical production of sodium chlorate (2) electrochemical oxidation of sodium chlorate to sodium perchlorate and (4) metathesis of sodium perchlorate to other metal perchlorates. The advent of commercially produced pure perchloric acid directly from hypochlorous acid means that several metal perchlorates can be prepared by the reaction of perchloric acid and a corresponding metal oxide, hydroxide, or carbonate. 

V-Chlorosuccinimide [128-09-6] mp 150—151°C, forms orthorhombic crystals and has a chlorine-like odor it is prepared from succinimide and hypochlorous acid (114,115). Because of its powerhil germicide properties, it is used ia disiafectants for drinking water. Like its bromine derivative, it is also a halogenating agent. 

Stable A/-chloro compounds are formed by reaction of hypochlorous acid and appropriate N—H compounds. For example, HOCl, formed in situ via chlorine hydrolysis, converts di- or trisodium cyanurates to dichloro- and trichloroiso-cyanuric acids, respectively (114). Chloroisocyanurates can also be prepared from isocyanuric acid or monosodium cyanurate and preformed HOCl (115—117). Hydrolysis of chloroisocyanurates provide HOCl for use in swimming pool disinfection and in bleaching appHcations. 

Organic solutions of HOCl can be prepared in near quantitative yield (98—99%) by extraction of CU -containing aqueous solutions of HOCl with polar solvents such as ketones, nitriles, and esters (131). These organic solutions of HOCl have been used to prepare chlorohydrins (132) and are especially useful for preparation of water-insoluble chlorohydrins. Hypochlorous acid in methyl ethyl ketone has also been used to prepare Ca(OCl)2, by reaction with CaO or Ca(OH)2 (133), and hydrazine by reaction with NH3 (134). 

Hypochlorination. Both ethylene chloiohydiin and propylene chloiohydiin were prepared by Wurtz (12) as a result of the reactions of HCl [7647-01-0] with the corresponding glycol under pressure. Shordy afterward, Carius (13) synthesized ethylene chlorohydria by reaction of hypochlorous acid with ethylene [74-85-1]. The first detailed iavestigation of the formation of ethylene chlorohydria by the reaction of ethylene with hypochlorous acid [7790-92-3] was performed by Gomberg (14). 

A 3-1., three-necked flask fitted with a mechanical stirrer, a dropping funnel, and a thermometer is then charged with an aqueous solution of 2.2 moles of calcium hypochlorite [Hypochlorous acid, calcium salt] (Note 3), and the piperidine acetate prepared above is placed in the dropping funnel. The hypochlorite solution is stirred and cooled to 0° to — 5° with a methanol-ice bath, and the piperidine acetate is added dropwise over a period of 1.25 hours while the temperature is maintained below 0°. After a further 15 minutes of stirring, equal portions of the mixture are placed in two 2-1. separatory funnels and extracted three times with a total of about 1300 ml. of ether. The ether extract is placed in a 2-1. flask and dried over anhydrous sodium sulfate in a cold room at 4° overnight. After filtration to remove inorganic material, the bulk of the ether is removed by boiling on a water bath maintained below 60° (Note 4). 

Iodoxybenzene has been prepared by the disproportionation of iodosobenzene,4Hi by oxidation of iodosobenzene with hypo-chlorous add or bleaching powder,7 and by oxidation of iodobenzene with hypochlorous acid or with sodium hydroxide and bromine.8 Other oxidizing agents used with iodobenzene include air,3 chlorine in pyridine,9 Caro s acid,19-11 concentrated chloric acid,15 and peracetic acid solution.13 Hypochlorite oxidation of iodobenzene dichloride has also been employed.14... 

The acid strengths and oxidizing abilities of the halogen oxoacids increase with the oxidation number of the halogen. The hypohalous acids, HXO (halogen oxidation number +1), are prepared by direct reaction of the halogen with water. For example, chlorine gas disproportionates in water to produce hypochlorous acid and hydrochloric acid ... 

Dichloroacetophenone has been prepared by chlorination of acetophenone with and without aluminum chloride 1 by action of dichloroacetyl chloride upon benzene and aluminum chloride 1 by action of hypochlorous acid upon phenylacetylene 2 by heating trichloromethylphenylcarbinol 3 and by chlorination of phenylacetylene in alcohol.4... 

On a large scale ethylene chlorhydrin is prepared by the addition of hypochlorous acid to ethylene, by passing C02 and ethylene simultaneously into a solution of bleaching powder. Concentrated potassium hydroxide solution converts chloroethyl alcohol into ethylene oxide, by removal of HC1 ... 

The preparation of dichloroacetone by the following methods is described in the literature the direct chlorination of acetone 1 the oxidation of dichlorohydrin 2 the action of silver chloride on diiodoacetone 3 the action of dichloropropene (CH2CI— CC1 = CH2) and hypochlorous acid 4 the action of hydrochloric acid on ethoxymonochloroacetoacetic ester 5 and the hydrolytic cleavage of dichloroacetoacetic ester.6... 

Butyl h3q)Ochlorite has been prepared by treatment of an alkaline solution of /-butyl alcohol with chlorine, - and a recent warning cautions against allowing the temperature to rise above 20° during this reaction. /-Butyl hypochlorite has been prepared in solution by shaking a solution of the alcohol in carbon tetrachloride, fluorotrichloromethane (Freon 11), and other solvents with aqueous hypochlorous acid. It has also been prepared by the action of chlorine on an aqueous /-butyl alcohol suspension of calcium carbonate, and by the action of chlorine monoxide on a carbon tetrachloride solution of the alcohol. ... 

The role of dialkylchloramines as intermediates in the chloride-catalyzed nitration of secondary amines is discussed in Section 5.3.1. Wright and co-workers" studied this reaction further and prepared a number of dialkylchloramines by treating secondary amines with aqueous hypochlorous acid (Equation 5.12). Treatment of these dialkylchloramines with nitric acid in acetic anhydride forms the corresponding secondary nitramine, a result consistent with the chloride-catalyzed nitration of amines." ... 

Wright and co-workers prepared a number of alkyldichloramines from the action of hypochlorous acid on primary amines and found these stable enough in acidic solution to undergo nitration with acetic anhydride-nitric acid mixtures to give the corresponding N-chloronitramines (Equation 5.13). A-Chloronitramines are isolatable intermediates and stable under acidic conditions, although some are sensitive and violent explosives. The presence of... 

The above reaction may be explosive and is not recommended for preparing hypochlorous acid. 

Hypochlorous acid, HO Cl, also may be used instead of chlorine in such preparation. 

In 1842 Balard succeeded Thenard at the Sorbonne, and in 1851 he accepted a professorship at the College de France (36). He discovered hypochlorous acid, worked out the constitution of Javelle water (44), and perfected industrial methods for the extraction of various salts from sea water. He worked for twenty years at these technical researches, and extracted sodium sulfate, the basis of the soda industry, directly from sea water. He also extracted potassium salts from the sea water, and his artificial potash, entering into competition with that from the ashes of plants, soon lowered the price. Before the discovery of the Stassfurt deposits in 1858, all the bromine used by photographers was prepared by Balard s method. 

In the preparation of hypochlorous acid from chlorine and water, the yield is very low, on account of the small solubility of chlorine in water. The yield of HC10 can be increased either by adding an insoluble oxide or carbonate which forms a sparingly soluble chloride. 

Chlorocyclopentanol has been prepared by the reaction of dry hydrogen chloride with 1,2-cyclopentanediol and by the addition of hypochlorous acid to cyclopentene. -... 

In 1834, A. J. Balard 1 prepared solutions of salts of hypochlorous acid—the hypochlorites—by mixing the aq. acid with alkalies, magnesia, or with zinc or copper hydroxides, and avoiding an excess of the acid. If the liquids are not kept cold, the hypochlorites decompose into chlorides and chlorates. A. J. Balard said ... 

A. J. Balard found that gold or platinum are not affected by hypochlorous acid, either alone or mixed with sulphuric or nitric acid. The last-named mixture, however, would probably act on both metals owing to the formation of free chlorine. No gold hypochlorite has yet been prepared. 

P. Grouvelle (1821)10 observed that a mol. of barium hydroxide absorbs two gram-atoms of chlorine, forming a product from which all the chlorine is expelled by carbon dioxide in two days. A. J. Balard (1834) says that the direct combination of hypochlorous acid with the powerful bases is accompanied by the development of much heat, and if the temp, is allowed to rise, the hypochlorite which may be formed changes into chlorate and chloride. By neutralizing a well-cooled soln. of the base with hypochlorous acid, A. J. Balard prepared soln. of calcium, strontium, and barium hypochlorites, the existence of which, he said, is incontestable and added that calcium and barium hypochlorites serve for the preparation of other hypo-... 

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