Sodium hypobromite

Marquillas Olondriz et al. (8) described a synthetic route consisting of oxidation of 3-acetyl-6,8-difluoro-l-methyl-7-(4-ethoxycarbonyl-3-methyl-l-piperazinyl)-4-oxo-l,4-dihydroquinoline to yield the 3-carboxylic analog, followed by deprotection of the piperazinyl amino group by aqueous alkaline hydrolysis. The oxidation may be carried out with sodium hypochlorite or sodium hypobromite. Sodium hydroxide or potassium hydroxide may be used for the alkaline hydrolysis. The reaction yield was 72 %. The results of the elemental analysis were ... 

HypohaUte solution (.see also Sodium hypobromite, sodium hypochlorite). Sodium hypochlorite solution can be prepared by passing chlorine into dilute alkali with ice cooling. Calcium hypochlorite is available commercially as a stable, water-soluble solid (trade names HTH, Perchloron). Suppliers Harshaw, McKesson... 

Hypohalites s. Acetyl hypo-bromite, Alkyl hypohalites, Hypochlorites, Potassium hypobromite. Sodium hypochlorite... 

Dissolve 36 g. of sodium hydroxide in 160 ml. of water contained in a 500 ml. conical flask, and chill the stirred solution to 0-5° in ice-water. Now add io-8 ml. (32-4 g.) of bromine slowly to the stirred solution exercise care in manipulating liquid bromine ) during this addition the temperature rises slightly, and it should again be reduced to 0-5°. Add a solution of 12 g. of acetamide in 20 ml. of water, in small portions, to the stirred hypobromite solution so that the temperature of the mixture does not exceed 20° the sodium acet-bromoamide is thus obtained in the alkaline solution. Now remove the flask from the ice-water, and set it aside at room temperature for 30 minutes. 

Action of hypobromite. To a solution of urea add sodium hypo-NH2CONH2 + 3NaOBr = Nj + CO2 4- 3NaBr + zHjO... 

Urea is decomposed by alkaline sodium hypobromite solution according to the equation ... 

Sodium Hypobromite. Dissolve 200 g. of NaOH in water, make up to I litre, chill in ice water, and slowly add 50 ml. of bromine with stirring. 

The pinacolone may be employed for the preparation of trimethylacetlc acid (plvallc acid) by oxidation with sodium hypobromite solution ... 

By treatment of an amide with sodium hypobromite or sodium hypochlorite solution (or with the halogen and alkali), the amine of one less carbon atom is produced, the net result being the elimination of the carbonyl group. An example is ... 

The hypobromite solution may be prepared by treating 6 ml. of bromine water with dilute sodium hydroxide solution dropwise, until the bromine colour is just discharged. 

Hydrazobenzene may be oxidised to azobenzene by sodium hypobromite solution at 0°. 

Method 2 (from hydrazobenzene). Prepare a solution of sodium hypobromite by adding 10 g. (3-2 ml.) of bromine dropwise to a cold solution of 6-0 g. of sodium hydroxide in 75 ml. of water immersed in an ice bath. Dissolve 9-5 g. of hydrazobenzene (Section IV,87) in 60 ml. of ether contained in a separatory funnel, and add the cold sodimn hypobromite solution in small portions. Shake for 10 minutes, preferably mechanically. Separate the ether layer, pour it into a 100 ml. distilling flask, and distil off the ether by warming gently on a water bath. Dissolve the warm liquid residue in about 30 ml. of alcohol, transfer to a small beaker, heat to boiling on a water bath, add water dropwise to the hot solution until the azobenzene just commences to separate, render the solution clear again with a few drops of alcohol, and cool in ice water. Filter the orange crystals at the pump, and wash with a little 50 per cent, alcohol. Dry in the air. The yield is 8 g. 

Anthranilic acid. This substance, the ortho amino derivative of benzoic acid, may be conveniently prepared by the action of sodium hypobromite (or sodium hypochlorite) solution upon phthalimide in alkaline solution at 80°. The ring in phthalimide is opened by hydrolysis to phthalamidic acid and the latter undergoes the Hofmann reaction (compare Section 111,116) ... 

Good results are obtained by the oxidation of the commercially available cyclo-propyl methyl ketone with sodium hypobromite solution, and the preparation may be regarded as an excellent example of the oxidation of the —COCH, group to — OOH ... 

Sodium hypobromite dissolve 100 g of NaOH in 250 mL of water and add 25 mL of bromine. Sodium nitrate, NaN03—Q.5N 43 g per liter. 

In alkaline solutions, iodine can be oxidized to iodate by sodium hypochlorite or hypobromite, whereas chlorine passed into a solution of iodine and alkah oxidizes ah the way to periodate. 

Hypobromites, the salts of hypobromous acid, do not keep well because they gradually disproportionate to bromide and bromate. Solutions are best prepared as needed from bromine and alkafl with cooling. Because disproportionation is catalyzed by cobalt, nickel, and copper (70), these impurities should be avoided. SoHd alkaline earth hypobromites, or more properly, bromide hypobromites such as calcium bromide hypobromite [67530-61 CaBr(OBr), have been known for many years, but the pure crystalline hydrates sodium hypobromite pentahydrate [13824-96-9] NaOBr 5H20, and potassium hypobromite tribydrate [13824-97-0], KOBr 3H20, were not described until 1952 (71). Hypobromites are strong bleaching agents, similar to hypochlorites. 

Similarly, bromofomi [75-25-2] CHBr, and iodoform [75-47-8] CHI, are obtained from sodium hypobromite and hypoiodite, respectively. Ethyl alcohol is the only primary alcohol that undergoes this reaction. 

Appropriate pyrido[2,3-d]pyrimidin-5-ones with formyl groups in the 6-position have been oxiized to piromidic (68) and pipemidic (69) acids, or to intermediates for these, using moist silver oxide, chromium trioxide (potassium dichromate), potassium permanganate or, alternatively, sodium chlorite/hydroxylamine-O-sulfonic acid. 6-Acetyl groups have been similarly oxidized using sodium hypobromite in aqueous dioxane, whilst 2-acetyl groups give dimethylaminomethylene derivatives en route to 2-pyrazolylpyrido[2,3-d]pyrimidines. 

Methylsuccinic acid has been prepared by the pyrolysis of tartaric acid from 1,2-dibromopropane or allyl halides by the action of potassium cyanide followed by hydrolysis by reduction of itaconic, citraconic, and mesaconic acids by hydrolysis of ketovalerolactonecarboxylic acid by decarboxylation of 1,1,2-propane tricarboxylic acid by oxidation of /3-methylcyclo-hexanone by fusion of gamboge with alkali by hydrog. nation and condensation of sodium lactate over nickel oxide from acetoacetic ester by successive alkylation with a methyl halide and a monohaloacetic ester by hydrolysis of oi-methyl-o -oxalosuccinic ester or a-methyl-a -acetosuccinic ester by action of hot, concentrated potassium hydroxide upon methyl-succinaldehyde dioxime from the ammonium salt of a-methyl-butyric acid by oxidation with. hydrogen peroxide from /9-methyllevulinic acid by oxidation with dilute nitric acid or hypobromite from /J-methyladipic acid and from the decomposition products of glyceric acid and pyruvic acid. The method described above is a modification of that of Higginbotham and Lapworth. ... 

Thus, Mathis et al. [1, 2] investigated oxidation reactions with 4-nitroperbenzoic acid, sodium hypobromite, osmium tetroxide and ruthenium tetroxide. Hamann et al. [3] employed phosphorus oxychloride in pyridine for dehydration. However, this method is accompanied by the disadvantages that the volume applied is increased because reagent has been added and that water is sometimes produced in the reaction and has to be removed before the chromatographic separation. 

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