Peracids commercial availability

Peracids are also available as aqueous solutions that contain the peracid in equihbrium with hydrogen peroxide and the parent acid. Peracetic acid [79-21-0] is commercially available as a 40% solution in dilute acetic acid. The water and dilution of the peracid make these solutions easier to handle than their sohd counterparts, but they still require careful handling and protection from heat. 

The most common method of epoxidation is the reaction of olefins with per-acids. For over twenty years, perbenzoic acid and monoperphthalic acid have been the most frequently used reagents. Recently, m-chloroperbenzoic acid has proved to be an equally efficient reagent which is commercially available (Aldrich Chemicals). The general electrophilic addition mechanism of the peracid-olefin reaction is currently believed to involve either an intra-molecularly bonded spiro species (1) or a 1,3-dipolar adduct of a carbonyl oxide, cf. (2). The electrophilic addition reaction is sensitive to steric effects. 

Although it was also Henbest who reported as early as 1965 the first asymmetric epoxidation by using a chiral peracid, without doubt, one of the methods of enantioselective synthesis most frequently used in the past few years has been the "asymmetric epoxidation" reported in 1980 by K.B. Sharpless [3] which meets almost all the requirements for being an "ideal" reaction. That is to say, complete stereofacial selectivities are achieved under catalytic conditions and working at the multigram scale. The method, which is summarised in Fig. 10.1, involves the titanium (IV)-catalysed epoxidation of allylic alcohols in the presence of tartaric esters as chiral ligands. The reagents for this asyimnetric epoxidation of primary allylic alcohols are L-(+)- or D-(-)-diethyl (DET) or diisopropyl (DIPT) tartrate,27 titanium tetraisopropoxide and water free solutions of fert-butyl hydroperoxide. The natural and unnatural diethyl tartrates, as well as titanium tetraisopropoxide are commercially available, and the required water-free solution of tert-bnty hydroperoxide is easily prepared from the commercially available isooctane solutions. 

The epoxidation of an alkene with peracid to give an oxirane. The commercial available mCPBA is a widely used reagent for this conversion, while magnesium mono-perphthalate and peracetic acid are also employed. 

Of the percarboxylic acids, commercially available m-chloroperbenzoic acid (MCPBA) is generally the most favored it is sometimes used at high temperatures in the presence of a radical inhibitor and the yield may be increased with peracid stabilizers. Inert solvents such as CH2CI2, CHCI3, and benzene are most commonly employed in the reaction Eq. 1. In basic solvents, the reaction rate decreases in proportion to the rise in basicity. With acid-sensitive olefins and in the preparation of acid-sensitive oxiranes, buffers are utilized recent work involves the advantageous use of an alkaline two-phase solvent. ... 

Other phenol derivatives that are used to form the backbone of an epoxy resin include bisphenol E, bisphenol F, resorcinol, brominated bisphenols, and more highly functionalized molecules such as tetrakisphenylolethane. Alcohols, amines, and carboxylic acids may be combined with epichlorohydrin to give a range of diglycidyl ether based epoxy resins. Non-aromatic, commercially available epoxides are produced by peracid epoxidation of alkenes and dienes, such as vinyl cyclohexene and esters of cyclohexane carboxylic acids [23]. The chemical formulas for two common uncured polymers are shown below ... 

Under comparatively drastic reaction conditions, camphor is oxidized with ring cleavage to give camphoric acid (69). Alternatively, bomeol may be used as starting material. Both enantiomers are commercially available. As oxidants nitric acid is most frequently used the best results are obtained when ammonium vanadate is added as a catalyst68. The ( + )-enantiomer was used for the preparation of monoperoxycamphoric acid, which is an isomeric mixture and difficult to separate69. The peracid has been applied with limited success as an enantioselective epoxidation reagent (Section D.4.5.2.). 

A variety of liquid bleach additives are now being offered in dual-chamber bottles to separate the bleach active component from alkalinity or sensitive enzymes. Several patents also describe the use of the peracid PAP in such formulations, but to date no such product is commercially available. 

Perbenzoic acid was one of the first peracids used to epoxidize PBD [118, 131]. Internal double bonds are epoxidized quantitatively by perbenzoic acid in the presence of the double bonds of 1,2-inserted butadienes [132]. This one-phase reaction can be used analytically to determine the content of 1,4-inserted units in PBD [131]. The commercial availability of m-CPBA makes it the preferred peroxide for epoxidation [100, 133-139]. m-CPBA epoxidizes double bonds quantitatively, although the 1,4-inserted butadiene units react faster [100]. The final epoxide content of the PBD can, thus, be controlled by the amount of m-CPBA added [138]. Despite its chemical benefits, m-CPBA is not used in large-scale epoxidation because of its high cost and the cost of disposal of mefa-chlorobenzoic acid residue. Epoxidations of PBDs are described with monoperphthalic acid using reactive mixing techniques [140]. The preparation of perphthalic acid from phthalic acid anhydride and hydrogen peroxide in solution was found to be convenient for the preparation of epoxidized polyenes, without notable side reactions [107, 141-143]. 

Commercial 40% (w/w) peracetic acid is available from the Becco Sales Corporation, Buffalo 7, New York. The use of a 3.3 molecular proportion of the peracid results in slightly higher and more consistent yields of product than when the theoretical 3.0 proportion is employed. The procedure gives the same yield (percentage) of product when using proportionately smaller quantities of reactants. 

Approximately 40% peracetic acid in acetic acid is available (Becco Chemical Division, Food Machinery and Chemical Corporation, Buffalo 7, New York). Sodium acetate is added to neutralize a small amount of sulfuric acid which is present in the commercial product. The peracetic acid concentration should be determined by titration.2 The peracetic acid solution used by the submitters contained 0.497 g. (0.00655 mole) of peracid per... 

Peracetic acid (b), commercial 40% peracetic acid. Material available from the Buffalo Electro Chemical Co. (Becco) has the composition 40% peracetic acid, 5% hydrogen peroxide, 39% acetic acid, 1% sulfuric acid, and 15% water. The density is 1.15 g. per ml. A fresh sample contains 0.77 mole of peracetic acid per 100 ml. Since the peracid content decreases somewhat on standing, an old sample should be analyzed by treating an aliquot with potassium iodide and titrating the liberated iodine with standard sodium thiosulfate. For certain uses it is advisable to neutralize the sulfuric acid present by addition of sodium acetate. 

While a number of synthetic routes are available to various sulfoxides, the primary methods for commercial production of DMSO involve oxidation of dimethyl sulfide by oxides of nitrogen or by air in the presence of NO cat-alyst.f Dimethyl sulfoxide is both the product and the reaction solvent. To alleviate the potential for exothermic, and potentially explosive, runaway reactions in these oxidations, the feed rate for dimethyl sulfide is adjusted to ensure complete conversion and, thus, low instantaneous concentrations at any time. Alternate oxidants for the conversion of sulfides to sulfoxides include nitric acid, H202/acetic acid, peracids, and halogen/water. ... 

---