Perphthalic acid

Ethylenic compounds when oxidised with perbenzoic acid or perphthalic acid in chloroform solution yield epoxides (or oxiranes). This Is sometimes known as the Prileschajew epoxidation reaction. Thus pyrene affords styrene oxide (or 2-plienyloxirane) ... 

Replacement of the carbamate function by an amide seems to be compatible with meprobamate-like activity in a compound formally derived from a 1,2-glycol. Oxidation of the commercially available aldehyde, 22, under controlled conditions affords the corresponding acid (23). This is then converted to its amide (24) via the acid chloride. Epoxidation by means of perphthalic acid affords oxanamide (25). ... 

Diphenylcyclopropene thione is transformed to diphenyl cyclopropenone by means of lead tetraacetate (presumably via 279/280), whilst perphthalic acid oxidizes to cation 281, which gives the unstable S-oxide 282 with NaHC03208. ... 

In such oxidations peracetic acid and perphthalic acids are reagents of choice and the following are some of the examples ... 

Palmitic acid, 69 o-Pelargonylphenol, 58 P-Pelaigonylphenol, 58 Pentaacetyl d-CLUcononitrile, 14,74 2,4-PENTANEDIONE, 6 Pentose synthesis, 14 Perkin reaction, 55 Peroxide, removal, 95 Perphthalic acid, mono-, 70... 

Perphthalic acid <550SC(3)619) is an even milder reagent that works even at —20 to 20 °C. Performic, permaleic and pertrifluoroacetic acids are strong oxidizing agents and they are recommended for AT-oxidation of the least reactive substrates. The last of the three is the most commonly used, especially for the oxidation of highly deactivated substrates (Scheme 16) such as perchloropyridine (electronic deactivation) (74MI20501) and 2,6-dibromopyridine (electronic and steric deactivation) (equation 35). 

Azaaromatic systems are usually oxidized to their A-oxides. Peracetic acid is the oxidant most used though for unstable substrates perbenzoic or perphthalic acids are preferable. They permit the use of non-polar solvents and milder conditions. Heterocycles relatively inert to oxidation can be converted to N-oxides by the more active performic or trifluoroperacetic acids. m-Chloroperbenzoic acid (MCPBA) also gives good results, especially when other easily oxidizable groups are present in heterocyclic molecule and therefore the question of selectivity is important. Thus, 2-aminopyridine was successfully converted with MCPBA into 2-aminopyridine A-oxide. 

Huffman and TarbellMD recently recorded unsuccessful attempts to synthesize a novel epiroepoxy ether by the oxidation of benz-JiydryJidonotetrahydrofuran with perbenzoic and perphthalic acids It conceivable that a labile epoxy ether wm formed, but that it underwent rearrangement. The authors observed that the crude product contained benzophenono and probably a y-lactcne which could be y-butvroiactone fEq. 217). 

Alkali lignin Unspecified Perphthalic acid oxidation 10 Redinger 1961... 

The Bohme procedure for preparing perphthalic acid from phthalic anhydride and hydrogen peroxide is sensitive to sKght variations in the experimental conditions. The present method gives reproducible yields with quite short reaction times. 

Reaction of imidazo[4,5-fc]pyridine (97), but not its 5-amino derivative, with perphthalic acid (49JA1885) or hydrogen peroxide in acetic acid (66UC403) gave the A( -oxide (98). Peracetic acid was used to prepare the A7 -oxides of 6-bromo-, 6-chloro, 6-bromo-5- and -7-methyl-, and 5,7-dimethyl-imidazo[4,5-fc]pyridine (98) (59JOC1455). The N-oxides can be catalytically reduced to (97) (80JHC17S7). 

Oxidation at N-4 (141) of the imidazo[4,5-c]pyridine ring system (140) has been accomplished with hydrogen peroxide in acetic acid and with perphthalic acid (64JOC2611,80JHC1757, 64CPB866). 

The peracid has been used for epoxidation and for Baeyer-Villiger oxidations yields in the former case range from 60 to 90 %, and from 64 to 85 % in the latter case. It corresponds generally to the reactivity of perbenzoic acid and perphthalic acid. 

Alkyl thietes may be oxidized in low yield to the sulfones with mono-perphthalic acid. An IR absorption at 1067cm suggested the presence of a sulfoxide in the oxidation of 228. Oxidation of the dialkyl thietes 229a and 229b with hydrogen peroxide in acetic anhydride gave 80-85% yields of ,J3-unsaturated aldehydes, possibly derived from an intermediate sulfoxide. The naphthothiete 205 yields either the sulfoxide or sulfone with w-chloroperbenzoic... 

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