Synthesis and purification of 5,5-dimethyl-1-pyrroline-N-oxide for biological applications

Eg, Janzen; Lt, Jandrisits; Rv, Shetty; Dl, Haire; Jw, Hilborn

doi:10.1016/0009-2797(89)90071-9

Cited by 31 publications

(20 citation statements)

References 18 publications

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“…Purification of DMPO 7 Commercially available (Fluorochem, 5 g, brown solid with a low melting point) 5,5-dimethyl-1-pyrroline-N-oxide (DMPO, 1.6 g) was weighed directly into a 10 mL round bottom flask which was equipped with a Vigreux column and a short-path condenser with three 10 mL round bottom flasks as fractions. The system was placed under vacuum (4.1 mbar).…”

Section: S24mentioning

confidence: 99%

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Arene Oxidation with Malonoyl Peroxides

et al. 2015

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Malonoyl peroxide 7, prepared in a single step from the commercially available diacid, is an effective reagent for the oxidation of aromatics. Reaction of an arene with peroxide 7 at room temperature leads to the corresponding protected phenol which can be unmasked by aminolysis. An ionic mechanism consistent with the experimental findings and supported by isotopic labeling, Hammett analysis, EPR investigations and reactivity profile studies is proposed.The oxidation and functionalization of hydrocarbons is a central facet of the chemical industry for the production of hightonnage commodities and the preparation of high-value pharmaceuticals, agrochemicals and fine chemicals. Therefore, methods for selective oxidation of C-H bonds are of great importance.1 Phenols represent a key class of oxidized hydrocarbon.2 While there are a small number of reports in which arenes are oxidized to the respective phenols using peroxides and strong acids as additives, 3 the oxidation of aromatic C-H bonds still presents a synthetic challenge specifically with respect to avoiding over oxidation. Scheme 1. C-H oxidation using phthaloyl peroxide. 2A recent report from the laboratories of Houk and Siegel described a metal-free oxidation of aromatic carbon-hydrogen bonds which was proposed to proceed through an intriguing reverse-rebound mechanism (Scheme 1). 4Reaction of mesitylene 2 with 1.3 equiv. of phthaloyl peroxide 1 in hexafluoroisopropanol (HFIP) followed by basic solvolysis gave the phenol 3 (97%). The method outlined in Scheme 1 represents a significant advance in arene oxidation. The proposed mechanistic pathway for the transformation suggested homolytic fission of the weak oxygen-oxygen bond leading to diradical 4. Addition of this radical to the arene gives 5 which though H-atom abstraction provides the observed product 6. Ester hydrolysis leads to the phenol 3 (97%, 2 steps). The procedure has wide functional group tolerance and arene over oxidation did not prove problematic. We believed two fundamental opportunities existed for development of this procedure: Firstly, phthaloyl peroxide 1 is known to be very shock sensitive and explodes violently when heated, representing a significant hazard. 5,6 Secondly, the proposed reverse-rebound mechanism leading to 6 was based upon theoretical studies. Provision of experimental evidence to support this pathway would be of great importance to the understanding and development of this procedure. In recent years we have been interested in the chemistry of cyclic diacylperoxides and have shown that malonoyl peroxide 7, 7 and related derivatives, 8 are effective for the syndihydroxylation of alkenes.9 This reagent provides significant advantages over phthaloyl peroxide 1 within the syndihydroxylation reaction in terms of yield, selectivity, reaction rate, substrate scope and operating temperature.10,11 Given our experience in understanding the mechanism of reactions involving the peroxide 7, 12 together with the specific advantages provided in alkene dihydroxylation we el...

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Section: S24mentioning

confidence: 99%

“…Provision of experimental evidence to support this pathway would be of great importance to the understanding and development of this procedure. In recent years we have been interested in the chemistry of cyclic diacylperoxides and have shown that malonoyl peroxide 7, 7 and related derivatives, 8 are effective for the syndihydroxylation of alkenes.…”

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confidence: 99%

Arene Oxidation with Malonoyl Peroxides

et al. 2015

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“…The concentrations of LOOH and LOH were also determined using an assumed molar extinction coefficient at 234 nm, 28,000 M -1 cm -1 (19). DMPO was purified by filtration with decolorizing activated carbon (Aldrich Chemical Company, Milwaukee, WI) immediately before use (8,20). The concentration of DMPO was determined using an assumed molar extinction coefficient at 234 nm, 7,700 M -1 cm -1 (21).…”

Section: Methodsmentioning

confidence: 99%

Formation of Superoxide Anion during Ferrous Ion-Induced Decomposition of Linoleic Acid Hydroperoxide under Aerobic Conditions

Kambayashi

Tero‐Kubota

Yamamoto

et al. 2003

Journal of Biochemistry

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“…28,32 For every 100 mg DMPO, 300 L water was added directly into storage ampoule to dissolve it. (Weighing DMPO is not feasible, because its melting point is near room temperature.)…”

Section: Purification and Quantification Of Dmpomentioning

confidence: 99%

In vitro evaluation of orthopedic composite cytotoxicity: Assessing the potential for postsurgical production of hydroxyl radicals

2004

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Hydroxyl radical (⅐OH)-induced inflammation is a primary mode for in vivo cytotoxicity. A legitimate concern is whether particulate wear debris from orthopedic composites can stimulate inflammation via ferrous ion (Fe 2؉ )-mediated production of ⅐OH. The purpose of this research was to utilize electron paramagnetic resonance (EPR) spin trapping in investigating and comparing the potential for postsurgical cytotoxicity induced specifically by ⅐OH in the presence of two composites: Simplex P and the novel, hybrid, CORTOSS™. Cytotoxicity is evaluated based on the composites competitively chelating catalytic Fe 2؉ or readily reducing ferric ions (Fe 3؉ ), in facilitating the Fenton reaction (FR). ⅐OH that are produced were then validated by a radical scavenger to confirm a genuine radical signal and mechanism. Spin adduct peak areas decreased in the presence of CORTOSS as opposed to increasing in the presence of Simplex P, evaluated against their respective controls. A plausible theory elucidating this finding is that CORTOSS may sequester the Fe form, by virtue of its monomers. Principally, direct comparison of composites indicated that Simplex P had greater tendency to produce ⅐OH, yielding 25.6 and 48.7% greater spin adduct peak areas when chelated and non-chelated Fe 2؉ are used, respectively. Moreover, the rate of FR accelerated when chelated Fe 2؉ was used, leading to the formation of a ternary complex with the composites. This was more prominent in Simplex P, as coordination of chelated Fe 2؉ occurs on its surface via an electrostatic attraction to allow a seventh coordination site for ligand exchange in the ternary complex, stabilized by Ba 2؉ . Conversely, the silica found in CORTOSS possesses radical quenching abilities that deactivate generated ⅐OH in impeding the efficiency of FR. Neither composite demonstrated a capacity to readily reduce Fe 3؉ to the relevant Fe 2؉ , as validated by a non-radical pathway. Instead, the artificial spin adduct signal attained when employing chelated Fe 3؉ was due to the nucleophilic addition of water onto DMPO. Simplex P may also serve as a template for surface catalysis of the nucleophilic addition of water onto DMPO involving chelated Fe 3؉ . CORTOSS is thought not to induce cytotoxicity, whereas the propensity of Simplex P in promoting Fenton chemistry is a serious issue that must be addressed.

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Synthesis and purification of 5,5-dimethyl-1-pyrroline-N-oxide for biological applications

Cited by 31 publications

References 18 publications

Arene Oxidation with Malonoyl Peroxides

Arene Oxidation with Malonoyl Peroxides

Formation of Superoxide Anion during Ferrous Ion-Induced Decomposition of Linoleic Acid Hydroperoxide under Aerobic Conditions

In vitro evaluation of orthopedic composite cytotoxicity: Assessing the potential for postsurgical production of hydroxyl radicals

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