Permaleic acid

The formation of a peracid by the reaction of an acid anhydride with hydrogen peroxide is well known. 

Cyclic dicarboxylic anydrides also undergo this reaction. However, it was not until 1962 that White and Emmons first showed the formation of permaleic acid 98. Generally, the reaction is carried out by reacting MA with a concentrated hydrogen peroxide solution in methylene chloride. The reaction is carried out at ice temperature. Other inert solvents such as chloroform, DMF, formamide, formic acid, benzene, and dioxane, have been used. 

White and Emmons in an excellent report claim that although permaleic acid is not quite as potent a peracid as trifluoroperacetic acid, it is stronger than other laboratory acids. It is reasonably stable in methylene chloride and decomposes —5% in 6 h at ambient temperature. One additional 

Permaleic acid is an excellent reagent for the Baeyer-Villiger reac-In the latter, an acyclic or a cyclic ketone is oxidized to the 

In Table 3.8, a number of ketones and yields of the product esters from these are given using permaleic acid as the reagent. The yields reported in Ref. 129 are also listed for comparison. 

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Oxidation. Maleic and fumaric acids are oxidized in aqueous solution by ozone [10028-15-6] (qv) (85). Products of the reaction include glyoxyhc acid [298-12-4], oxalic acid [144-62-7], and formic acid [64-18-6], Catalytic oxidation of aqueous maleic acid occurs with hydrogen peroxide [7722-84-1] in the presence of sodium tungstate(VI) [13472-45-2] (86) and sodium molybdate(VI) [7631-95-0] (87). Both catalyst systems avoid formation of tartaric acid [133-37-9] and produce i j -epoxysuccinic acid [16533-72-5] at pH values above 5. The reaction of maleic anhydride and hydrogen peroxide in an inert solvent (methylene chloride [75-09-2]) gives permaleic acid [4565-24-6], HOOC—CH=CH—CO H (88) which is useful in Baeyer-ViUiger reactions. Both maleate and fumarate [142-42-7] are hydroxylated to tartaric acid using an osmium tetroxide [20816-12-0]/io 2LX.e [15454-31 -6] catalyst system (89). 

More recently, permaleic acid has been recommended as a very satisfactory reagent for the Baeyer-Villiger reaction. It reacts almost as fast as trifluoroperoxyacetic acid and does not require buffering. Unfortunately, neither of these two reagents has been used extensively on 20-keto steroids a patent claims the conversion of progesterone to testosterone acetate with trifluoroperoxyacetic acid, but a later communication describes the ready reaction of 3-keto-A" -steroids with this reagent. 

Hydroxyquinoxaline (98) is converted into the 1,4-dioxide (99), and 5-acetamido-7-methylquinoxaline similarly forms the 1,4-dioxide with m-chloroperbenzoic acid in benzene.195a,b 2-Aminoquinoxaline is best oxidized with permaleic acid in ethanol in the presence of sodium bicarbonate. Exclusive 1-oxidation occurs, and the product is conveniently isolated as the carbamic acid ester (100) (85%).115... 

Forexample, good yields of 2-chloropyrazine 4-oxide,391,392 2-carbox-amidopyrazine 4-oxide,392 and 2-methylpyrazine 1,4-dioxide,391 have been obtained by oxidation of the appropriate pyrazine. In general, the preferred product from oxidation of monosubstituted pyrazines at lower temperatures is the monooxide formed by oxidation on the nitrogen remote from the substituent, whereas 1,4-dioxides are obtained by prolonged heating at higher temperatures.155 Pertrifluoro-acetic acid oxidation of 2,5-dichloro-3,6-dimethylpyrazine furnishes the di-iV-oxide, whereas permaleic acid gives only the mono-iV-oxide.393... 

One of the most important methods for lactone preparation, and hence of the corresponding hydroxy acids (or halogeno acids, Section 5.14.1 above) is the Baeyer- Villiger rearrangment of cyclic ketones by the action of peracids. A wide variety of peracids have been used in this reaction but currently the reagents of choice are pertrifluoroacetic acid, m-chloroperbenzoic acid, and permaleic acid. The mechanism is formulated below for the conversion of an acyclic ketone into an ester. 

For reactions where the presence of strong acids may give undesirable side reactions, such as lactone ring-opening, pre-formed peracids such as MCPBA,251 permaleic acid,252 monoperphthalic253 or MMPP254 may be used as alternatives to distilled peracetic acid (Figure 3.55). 

Oxidation methods BAEVER-ViixioEn reaction Caro s acid. m-Chloroperbenzoic acid. Hydrogen peroxide. Peracetic acid. Permaleic acid, pertrifluoroacetic acid. 

Perchloropropylene, 938 Perchlorotoluene, 1131 Perchlorylbenzene, 803 Perchloryl fluoride, 802-808 Perfluorocyclobutanone, 171 Perfluorocyclopropane, 1237 Perfluoropropene, 117 Pefformic acid, 457-458, 759 Perhydroanthracene, 579, 580 Perhydroazulenes, 103,104 Perhydrosqualene, 1165 Perillyl alcohol, 568 Perinaphthanones, 1257 Perinaphthenones, 1257 Periodates, 809-815 Periodic acid, 815-819 Periplogenin, 614 Permaleic acid, 819 Permutit resins, 512 Peroxybenzoic acid, 458 Peropyrene, 1272... 

Epoxidation I-Butylhydroperoxide. m-Chloroperbenzoic add. Hexamethylphosphorous triamide. Hydrogen peroxide. p-Nitroperbenzoic acid. Peracetic acid. Perbenzoic acid. Permaleic acid. Perphthalic acid. Sodium hypochlorite. 

Periodic acid-Chromic acid [1,819 before Permaleic acid], Perold and Pachler1 used the combination of periodic and chromic acid to degrade the primary-secondary... 

Oxidative cyclization of o-aminoacylbenzenes is a much less common process for the synthesis of anthranils than the reductive cyclizations discussed in the previous section, mainly because the o-aminoketones are in many instances best prepared by reductive ring opening of anthranils (see Section III,C,3). Nevertheless, a few examples have been recorded. Oxidation of o-aminobenzophenones to the nitroketones using peroxytrifluoro-acetic acid, permaleic acid, or persulfuric acid proceed via the 3-phenyl-anthranil which occasionally is isolable.168 Caro s acid is also a useful oxidant.169... 

The most convenient reagent for oxidizing quinoxalines to their N-oxides is 30% aqueous hydrogen peroxide in acetic acid. However in the case of quinoxaline itself, treatment with this reagent gives mainly quinoxaline-2,3-dione (2,3-dihydroxyquinoxaline). Conversion to the 1-oxide has been achieved by reaction with one equivalent of peracetic acid in acetic acid and with excess of peracetic acid, quinoxaline 1,4-dioxide is formed. Alternative reagents that have been used to oxidize quinoxalines include monoperphthalic acid," m-chloroperbenzoic acid, and permaleic acid. ... 

Oxidation of sulfur compounds. With maleic anhydride (forming permaleic acid),... 

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