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• 98-89-5 Cyclohexanecarboxylic acid 

Relevant academic research and scientific papers

The loss of carbon dioxide from activated perbenzoate anions in the gas phase: Unimolecular rearrangement via epoxidation of the benzene ring

The unimolecular reactivities of a range of perbenzoate anions (X-C 6H5CO3-), including the perbenzoate anion itself (X = H), nitroperbenzoates (X = para-, meta-, orrtho-NO 2), and methoxyperbenzoates (X = para-, meta-OCH3) were investigated in the gas phase by electrospray ionization tandem mass spectrometry. The collision-induced dissociation mass spectra of these compounds reveal product ions consistent with a major loss of carbon dioxide requiring unimolecular rearrangement of the perbenzoate anion prior to fragmentation. Isotopic labeling of the perbenzoate anion supports rearrangement via an initial nucleophilic aromatic substitution at the ortho carbon of the benzene ring, while data from substituted perbenzoates indicate that nucleophilic attack at the ipso carbon can be induced in the presence of electron-withdrawing moieties at the ortho and para positions. Electronic structure calculations carried out at the B3LYP/6-311++G(d,p) level of theory reveal two competing reaction pathways for decarboxylation of perbenzoate anions via initial nucleophilic substitution at the ortho and ipso positions, respectively. Somewhat surprisingly, however, the computational data indicate that the reaction proceeds in both instances via epoxidation of the benzene ring with decarboxylation resulting-at least initially-in the formation of oxepin or benzene oxide anions rather than the energetically favored phenoxide anion. As such, this novel rearrangement of perbenzoate anions provides an intriguing new pathway for epoxidation of the usually inert benzene ring.

Efficient synthesis of ω-functionalized nonanoic acids

Starting from cyclohexanone and acrylonitrile, a four-step synthesis of the title open-chain C9 compounds is reported. An improved protocol for cyanoethylation of cyclohexanone in the presence of a catalytic amount of cyclohexylamine afforded 3-(2-oxocyclohexyl)propanenitrile (1) in 92% yield. Cyclohexaneperoxycarboxylic acid (CHPCA) is introduced as a highly efficient reagent in the Baeyer-Villiger rearrangement of 1, yielding over 90% of 2. Pyrolysis of 2 afforded under optimized conditions 3 in 92% yield and 99% regioisomeric purity, otherwise a mixture of three unsaturated isomeric ω-cyano nonenoic acids 3, 10 and 11 is obtained. Partial hydrogenation of 3 allowed the isolation of 4 in 90% yield. Hydrogenation of 4 at elevated hydrogen pressure gave 9-aminononanoic acid (5), whereas hydrolysis of 4 led to 1,9-nonanedioic acid (azelaic acid, 6). Both, 5 and 6 are valuable C9 monomers for the preparation of polyamides with specific properties.

NOUVEAUX DECONTAMINANTS. DESTRUCTION DE TOXIQUES ORGANOPHOSPHORES OU SOUFRES PAR DES PERACIDES MONO-, BI- ET TRICYCLIQUES SATURES

New peroxycarboxylic and peroxyacetic acids have been tested for the destruction of some organophosphorus compounds and mustards.The peroxyacids used have monocyclic, bicyclic or tricyclic structures.These are very reactive against paraoxon or HD and the addition of certain surfactants enhances the reaction rate.Very short half-live times are obtained with these compounds.