Sodium perborate, reaction with

Write a balanced net ionic equation describing the reaction in acid solution of sodium perborate, NaB03, with each of the following, and indicate any color changes that you would expect. 

In a 1-1. three-necked round-bottomed flask equipped with an eflicient stirrer, a reflux condenser, and a thermometer (Note 1) are placed 500 ml. of glacial acetic acid (Note 2), 29.0 g. (0.19 mole) of -aminoacetanilide (Note 3), 40 g. (0.26 mole) of sodium perborate tetrahydrate, and 10 g. (0.16 mole) of boric acid. The mixture is heated with stirring to 50-60° and held at this temperature for 6 hours. Initially the solids dissolve but, after heating for approximately 40 minutes, the product begins to separate. At the end of the reaction period, the mixture is cooled to room temperature and the yellow product is collected on a Buchner funnel. It is washed with water until the washings are neutral to pH paper (Note 4) and then dried in an oven at 110°. The yield of 4,4 -bis(acetamido)a2obenzene, m.p. 288-293° (dec.), is 16.5 g. (57.7%). It is used as such for the hydrolysis step (Note 5). 

Sodium perborate is used in laundry detergents and bleaches. It releases more hydrogen peroxide than borax when it reacts with water. Hydrogen peroxide acts as a bleach, and its action is aided by the alkaline solution that is also produced by the reaction. 

This is an alternative method of introducing copper into an o-hydroxyazo dye structure. The azo compound is treated with a copper(II) salt and an oxidant in an aqueous medium at 40-70 °C and pH 4.5-7.0. Sodium peroxide, sodium perborate, hydrogen peroxide or other salts of peroxy acids may be used as oxidants, the function of which is to introduce a second hydroxy group in the o -position [25]. This process is reminiscent of earlier work on Cl Acid Red 14 (5.51 X = H), an o-hydroxyazo dye that will not react with a chromium (III) salt to form a 1 1 complex but will do so by oxidation with an acidified dichromate solution. This oxidation product was later found to be identical with that obtained by conventional reaction of Cl Mordant Black 3 (5.51 X = OH) with a chromium(III) salt [7]. 

Sodium perborate oxidation of alcohols by is aided by Aliquat, but also requires the addition of chromium oxide [17]. However, the long reaction times at 60-80°C and the variable yields do not make the procedure particularly attractive. In contrast, direct epoxidation of a,p-unsaturatcd ketones has been conducted with moderate success using sodium perborate catalysed by tetra-n-hexylammonium hydrogen sulphate [18, 19]. 

Reaction of Sodium Perborate with Organophosphorus Esters... 

Table 1. Experimental Data for Reaction of Sodium Perborate with PDEP at pH 8 (Run 4953-22)...

Figure 1. Pseudo-first-order kinetic plot of - n(A -Ao)/ A -Ag) versus time for production of p-nitrophenolate from reaction of sodium perborate at various concentrations with EPMP at 27.5 oc, pH = 8.

SAMP-Hydrazones derived from ketones may also be cleaved by treatment with three equivalents of sodium perborate tetrahydrate at pH 7 in water/rert-butyl alcohol at 60 °C. Hydrolysis of aliphatic derivatives is effected in 4-24 hours and reactions yielding aromatic ketones proceed within 2- 3 days. This cleavage reaction furnishes the desired ketones chemoselectively in the presence of olefinic double bonds in 85-95% yield (cyclopentanone 70% yield)30. 

A 500-ml three-necked flask was charged with 2,7-dibromo-9-fluorenone (6.65 g), 140 ml trifluoroacetic acid/chloroform, 1 1, and sodium perborate monohydrate and then stirred for 20 hours. The reaction liquid was filtrated through Celite and then washed with toluene. The filtrate was washed with water, sodium hydrogen sulfite, and saturated saline and then dried over Na2SC>4. After concentration 6.11 g of residue was obtained. After recrystallization from chloroform 1.19 g of product was isolated. 

A -Arylimincs (21a) can be oxidatively rearranged to fonnamides (21b) with sodium perborate.42 The reaction works best for secondary or aryl R groups. An oxaziridine intermediate is proposed. Results with chiral secondary R groups indicate epimeriza-tion, suggested to occur via equilibration of (21a) with its enamine tautomer. 

The ability of other peracids28, sodium perborate and sodium percarbonate29, to release oxidative species in an organic medium has made them useful reagents in organic synthesis. The oldest organic reaction reported with sodium perborate concerns the formation of peracids (equation 5). 

Sodium perborate (NaB03 nH20 n = 1-4) is a cheap and widely used industrial chemical. If sulfuric acid is added to a mixture of the perborate and an alkene in acetic anhydride, an exothermic reaction occurs leading to anti addition to the double bond with formation of the corresponding l-hydroxy-2-ace-toxy derivative in moderate yield. Peroxybis(diacetoxy)borane, (AcO)2BOOB(OAc)2, may be the reactive species in this oxidation and it seems likely that the epoxide is an intermediate. 

An early study" " of the decomposition of sodium perborate in aqueous solution indicated that the process is not kinetically simple. Although approximately first-order, the reaction is said to be subject to retardation (possibly due to reversibility) by the reaction products and to slight acceleration by polymeric borate species. A number of catalytic species were found and others have been reported since, e.g. Wilson" and Prokopeikas et The reaction with iodide has been used as the basis for a kinetic method of analysis for molybdate". ... 

Similar migration of the other two R groups and hydrolysis of the B-0 bonds leads to the alcohol and boric acid. Retention of configuration is observed in R. Boranes can also be oxidized to borates in good yields with oxygen," with sodium perborate NaBOs," " and with trimethylamine oxide, either anhydrous" or in the form of the dibydrate." The reaction with oxygen is free radical in nature." ... 

In our experience pulverization of phthalic anhydride is tedious and we prefer crystallization, which provides material in a form suitable for ready reaction and which eliminates any phthalic acid, usually present in a sample taken from a previously opened bottle. The anhydride is boiled with a liberal quantity of benzene, and the hot solution is filtered from any undissolved phthalic acid and diluted with ligroin. A modification of a published method is as follows. A mixture of 66 g. of the crystallized anhydride, 92 g. of sodium perborate, and 280 ml. of water is stirred at 0° for 2 hrs., shaken with ether, and acidified with 120 ml. of ice-cold 30% sulfuric acid. Extraction is done as described above. 

See also Perphthalic acid for the reaction of sodium perborate with phthalic anhydride. 

The epoxidation of alkenes by means of either sodium perborate or sodium percarbonate and acetic anhydride can be enhanced by sonication [46], When sodium perborate was used with sonication, the reaction time could be reduced significantly, but the yield was not significantly improved. With sodium percarbonate both a higher yield and a shorter reaction time were obtained. The mechanistic aspects of these reactions were discussed. 

Practically all leuco compounds of vat dyes will oxidize on exposure to air but the reaction often takes 30 to 45 minutes to complete. When the goods are in an open state and air has access to every part, atmospheric oxidation does not present much difficulty. When the material is in a dense mass such as a tightly-wound roll or a cheese or cone of yarn, the penetration of air to the innermost portions may be slow and in such cases treatment with an oxidizing agent is of assistance. The goods can be rinsed with cold water and then treated for 10 to 20 minutes at 30° to 40°C (86° to 104°F) in a liquor containing 1 to 2 parts per 1000 of potassium dichromate and 2 5 to 10 parts of 30 per cent acetic acid. More frequently the oxidation is carried out at 40° to 50°C (104° to 122°F) in a solution containing 3 parts of sodium percarbonate or 2 parts of sodium perborate per 1000, followed by a rinse and treatment with dilute acetic acid (6 to 10 parts of 30 per cent acid per 1000) to neutralize the alkali derived from the per-salt. 

ROH, toluene, reflux, 95% yield. The reaction in this case is proposed to proceed through a ketene intermediate. Similar conditions with catalytic sodium perborate give esters in 58-90% yields. ... 

Oxidations of 2,2 -diaminobiphenyls with sodium perborate, phenyl iodosodiacetate, ° or manganese dioxide have given benzo[c]cinnolines with hydrogen peroxide in acetic acid, cyclization is accompanied by N-oxidation. These reactions, which parallel the oxidation of arylamines... 

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