Peroxybenzoic acid preparation

Numerous methods of preparing peroxy acids are described in the literature,2 3 and many of them have been applied to the synthesis of peroxybenzoic acid. A common way of preparing it has been by the action of sodium methoxide on benzoyl peroxide followed by acidification.3 The present method is adapted from one in a recent publication.4... 

Malonic acid, amino-, diethyl ester, HYDROCHLORIDE, 40, 24 Malonic acid, bts(hydroxymethyl)-, DIETHYL ETHER, 40, 27 Malonitrile, condensation with tetra-cyanoethylene, 41, 99 2-Mercaptopyrimidine, 43, 6S hydrochloride of, 43, 68 Mercuric oxide in preparation of bromo-cyclopropane, 43, 9 Mesityl isocyanide, 41,103 5-Methallyl-l,2,3,4,5-pentachlorocyclo-pentadiene, 43, 92 Methane, dimesityl-, 43, 57 Methanesiileinyl chloride, 40, 62 Methanesulfonic acid, solvent for making peroxybenzoic acid from benzoic acid, 43, 93... 

What procedure is available for the preparation of epoxides Answer Procedure VII-3 which would require an olefin and peroxybenzoic acid. The structure of the required olefin can be determined by placing the double bond between Ihe carbons which contain the ether linkages in VII-b. 

Benzoic acid anhydride is formed by the reaction of sodium benzoate with benzoyl chloride. Dibenzoyl peroxide and peroxybenzoic acid can be prepared from the acid chloride by reaction with hydrogen peroxide (Scheme 5.9). 

Instead of acetates also free aldehydes may be oxidized The oxidation of acrolein is carried out at 313 K in benzene For polyCu- and polyFePc, pyridine is needed to activate the oxidation. From benzaldehyde and others a mixture of benzoic acid and peroxybenzoic acid is produced with Cu- and FePc derivatives (95) (prepared from TCB and metal dilorides in ethylene glycol) (Eq.45) The reactions were carried out in various solvents at %3 K. 

Peroxybenzoic acid (perbenzoic acid), CgHsCOjH (mp 41-43 C), is commercially available. It is prepared from dibenzoyl peroxide according to equation 16 [293] and is obtained as a solution in chloroform. The peroxyacid content of the solution can be determined iodometrically [293]. 

Solid peroxybenzoic acid is obtained by evaporation of the chloroform under reduced pressure. Better procedures for the preparation of peroxybenzoic acid are the reaction of benzoyl chloride with sodium peroxide [294] and the treatment of benzoic acid with 70% hydrogen peroxide in the presence of methanesulfonic acid [176]. Peroxybenzoic acid can also be prepared in situ from benzaldehyde and oxygen [295] or ozone [772]. 

Oxidations with peroxybenzoic acid are carried out in solutions in dichloromethane, chloroform, benzene, ether, or ethyl acetate at or below room temperature and include epoxidation of double bonds [295, 296, 297, 298, 299, 300, 301], oxidation of benzaldehydes to carboxylic acids or phenols [302], the Baeyer-Villiger reaction of ketones [303, 304, 305, 306, 307], and oxidation of sulfides to sulfoxides [308, 309]. Peroxybenzoic acid is also used for the anti hydroxylation of double bonds [310], the oxidation of pyrrolidines to pyrrolidones [377] and of pyrroles to succinimides [377], and the preparation of azoxy compounds from azo compounds [372]. 

Hydroxylation at double bonds of unsaturated carboxylic acids is accomplished stereoselectively by the same reagents as those used to hy-droxylate alkenes. syn Hydroxylation is carried out with potassium permanganate [101] or osmium tetroxide with hydrogen peroxide [130], sodium chlorate [310, 715], potassium chlorate [715], or silver chlorate [310] as reoxidant, anti Hydroxylation is achieved with peroxyacids, such as peroxybenzoic acid [310] or peroxyformic acid, prepared in situ from hydrogen peroxide and formic acid [101] (equation 472). 

Preparation of perbenzoic acid (peroxybenzoic acid). In an improved procedure" 0.45 mole of 70% hydrogen peroxide is added dropwise behind a safety shield to a... 

The first iV-oxidation of alkoxypyrimidines was reported by Ochiai and Yamanaka, who used hydrogen peroxide-acetic acid. Cytidine iV -oxide (232) has been prepared by the oxidation of cytidine with m-chloro-peroxybenzoic acid in glacial acetic acid. The AT -oxide of cytidine 5 -phosphate has also been prepared. ... 

Pyrimidine nucleosides have been chlorinated at the 5-position with m-chloro-peroxybenzoic acid in DMA-HCl thus uridine gives 5-chlorouridine (114) in 90% yield, and 8-chloropurines have been similarly prepared. ... 

Peroxybenzoic acid (often called simply perbenzoic acid) is the commonest reagent for preparation of epoxides. It is best obtained directly from benzoyl chloride and sodium peroxide29 or by cleavage of dibenzoyl peroxide with sodium alkoxide 30... 

A solution of dibenzoyl peroxide (10 g) in toluene (20 ml) is cooled, with stirring, to —5° and then treated during 5 min with a pre-cooled (—2°) solution of sodium (2 g) in 96% ethanol (50 ml). Sodium peroxybenzoate separates at once. To this mixture is added ice-water, in which the sodium peroxybenzoate dissolves. The aqueous peroxybenzoate solution is separated from the toluene in a separatory funnel and washed twice with ether which removes residual toluene and ethyl benzoate. This purified aqueous solution is cooled and treated with a mixture of concentrated sulfuric acid (5 g) and ice-water (60 g), and the per-oxybenzoic acid liberated is shaken into chloroform (60 ml in two portions). The chloroform extracts are united and dried over sodium sulfate they may then be used for oxidations. For preparation of crystalline peroxybenzoic acid the chloroform is evaporated in a stream of dry air at ca. 30 mm and 25-30°. The content of active oxygen is determined by iodometric titration. 

Epoxides are usually prepared from olefins and peroxy acids (especially peroxybenzoic acid) according to the following general procedure The olefin is dissolved in chloroform, cooled, and treated with a slight excess of peroxy add in cold chloroform. The reaction mixture is set aside at 0°, or for less reactive olefins at room temperature. The course of the reaction is followed by titration of small samples when the reaction is ended, unchanged peroxy acid and the carboxylic acid formed are carefully extracted, and the chloroform solution is worked up. 

The preparation of styrene oxide (phenyloxirane) may be described as an example 33 Styrene (30 g, 0.29 mole) is added to a solution of peroxybenzoic acid (42 g, 0.30 mole) in chloroform (500 ml), and the mixture is set aside at 0° for 24 h, being repeatedly shaken during the first few hours. Completion of the oxidation can be determined by titration of an aliquot part of the chloroform solution. Then the benzoic acid formed and the small excess of peroxybenzoic acid are removed by repeated extraction with 10% sodium hydroxide solution, and the organic phase is washed with water until free from alkali and then dried over sodium sulfate. Fractional distillation affords styrene oxide (24-26 g, 70-75 %) as a colorless liquid, b.p. 101°/40mm. 

Benzaldehyde reacts readily with molecular oxygen with formation of peroxybenzoic acid (see the Section Autoxidation ). This tendency of benzaldehyde to autoxidation has been utilized in an epoxidation procedure that avoids the preparation of pure peroxy acid.34 It is only necessary to treat an olefin-benzaldehyde mixture with oxygen or air to obtain the epoxides in good yield. Yields of epoxide are, however, poor if an aliphatic aldehyde is used.35... 

Monoperoxyphthalic acid can be used for preparation of epoxides in the same way as peroxybenzoic acid. In general, good yields are obtained under almost the same conditions as with peroxybenzoic acid, but monoperoxyphthalic acid has the advantage that it is more stable. Because of this stability monoperoxyphthalic acid is particularly suited for epoxidation of less reactive olefins when reaction is effected in chloroform solution the phthalic acid produced is readily separated because it is insoluble in this solvent. 

Substrates of this type were utilized for the synthesis of alditols. Schneider and co-workers prepared from trans and cis 2-buten-1,4-diols 2,3-anhydro-DL-erythritol (54) and -threitol (55) by direct epoxidation with peroxybenzoic acid. This method of epoxide formation failed in the case of 2 ,4 -hexadiene-l,6-diol from the 2Z,4Z isomer the corresponding diepoxide (57) was obtained in a 2% yield only. However, from 1,6-dibromo-and 1,6-dibenzyloxycarbonyloxy-2 ,4 -hexadienes the corresponding derivatives of 2,3 4,5-dianhydro-DL-gal-actitol (56) could be obtained in moderate yields. Compounds of this type are active against some forms of sarcoma. 

If compound Y is prepared by treatment of compound X with peroxybenzoic acid, compound Y would be obtained as ... 

The most widely used reaction in this category is the conversion of olefins to epoxides. In most cases, one of several peroxycarboxylic acids is used to effect oxidation. m-Chloroperoxybenzoic acid, which is commercially available or readily prepared and is a quite stable solid, is the most popular reagent. Peroxyacetic acid, peroxybenzoic acid, peroxytrifluoroacetic acid, and others, however, have also been used frequently. 

Formation.—Thiiran 1-oxides are conveniently prepared by the oxidation of thiirans with peroxybenzoic acid or m-chloroperoxybenzoic acid in... 

Oxidants suitable for the partial oxidation of amines to nitroso compounds are peroxy acids Caro acid, which is prepared in situ from potassium persulfate and sulfuric acid [195, 199 potassium peroxysulfate (Oxone) [295] peroxyacetic acid [i53], and peroxybenzoic add [1186], 3-Nitro-o-toluidine [195] and 5-nitro-o-toluidine [199] in aqueous-alcoholic solutions, when treated with a mixture of potassium persulfate and concentrated sulfuric acid, give 3-nitro-2-nitrosotoluene and 5-nitro-2-nitrosotoluene in respective yields of 60 and 55-66%. Organic peroxy acids convert 2,6-dihaloanilines into 2,6-dihalonitrosobenzenes (equation 497) [753, 1186]. p-Phenylenediamine (1,4-diaminobenzene) is oxidized by Oxone (2KHS05 KHS04 K2S04) in an aqueous suspension at room temperature to p-dinitrosobenzene in a quantitative yield [205]. 

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