Dioximes, hydrogenation

Methylsuccinic acid has been prepared by the pyrolysis of tartaric acid from 1,2-dibromopropane or allyl halides by the action of potassium cyanide followed by hydrolysis by reduction of itaconic, citraconic, and mesaconic acids by hydrolysis of ketovalerolactonecarboxylic acid by decarboxylation of 1,1,2-propane tricarboxylic acid by oxidation of /3-methylcyclo-hexanone by fusion of gamboge with alkali by hydrog. nation and condensation of sodium lactate over nickel oxide from acetoacetic ester by successive alkylation with a methyl halide and a monohaloacetic ester by hydrolysis of oi-methyl-o -oxalosuccinic ester or a-methyl-a -acetosuccinic ester by action of hot, concentrated potassium hydroxide upon methyl-succinaldehyde dioxime from the ammonium salt of a-methyl-butyric acid by oxidation with. hydrogen peroxide from /9-methyllevulinic acid by oxidation with dilute nitric acid or hypobromite from /J-methyladipic acid and from the decomposition products of glyceric acid and pyruvic acid. The method described above is a modification of that of Higginbotham and Lapworth. ... 

Other mild oxidising agents which abstract the terminal hydrogen atoms and thus facilitate disulphide formation may be used as vulcanising agents. They include benzoyl peroxide, p-nitrosobenzene and p-quinone dioxime. 

When the 1-monoximes or dioximes of 4-acetyl-l-tetralones are hydrogenated in the presence of palladium, mixtures of diastereoisomeric 1-aminotetralones are formed. The m-aminoketone isomers readily form dehydrobenzoisoquinuclideines (3,4-disubstituted-1,4-dihydro-1,4-ethano-isoquinolines). Quaternary immonium salts prepared from these bicyclic imines are then converted by bases to bicyclic enamines [2,4-disubstituted-3-alkylidene-1,4-ethano-1,2,3,4-tetrahydroisoquinolines (25)]. 

Fig. 31. Complexes of type 120-126 are derivatives of M(dioxime)2 complexes 119, in which the hydrogen bridges have been replaced by diorganoboryl groups...

Olah and co-workers reported the synthesis of 2,2,5,5-tetranitronorbornane (127) from 2,5-norbornadiene (122). In this synthesis formylation of (122) with formic acid yields the diformate ester (123), which on treatment with chrominm trioxide in acetone yields 2,5-norbomadione (124). Formation of the dioxime (125) from 2,5-norbornadione (124) is followed by direct oxidation to 2,5-dinitronorbomane (126) with peroxytriflnoroacetic acid generated in situ from the reaction of 90 % hydrogen peroxide with TFAA. Oxidative nitration of 2,5-dinitronorbornane (126) with sodium nitrite and potassium ferricyanide in alkaline solution generates 2,2,5,5-tetranitronorbornane (127) in excellent yield. 

Baum and Archibald reported the synthesis of 2,2,6,6-tetranitrobicyclo[3.3.1]nonane (142). This synthesis starts from the dioxime (140), which on halogenation with chlorine, followed by oxidation with hypochlorite and reductive dehalogenation with hydrogen in the presence of palladium on carbon, yields 2,6-dinitrobicyclo[3.3.1]nonane (141). Oxidative nitration of (141) with sodium nitrite and silver nitrate under alkaline conditions yields 2,2,6,6-tetranitrobi-cyclo[3.3.1]nonane (142). The greater molecular freedom in 2,2,6,6-tetranitrobicyclo[3.3.1] nonane (crystal density-1.45 g/cm ) compared to the isomeric 2,2,6,6-tetranitroadamantane (crystal density-1.75 g/cm ) is reflected is their considerably different crystal densities. 

Protonation of DNM might lead to three different tautomers (i) dinitrosomethane (H2C(NO)2) when the protonation occurs at the carbon (ketonic isomer) , (ii) methylnitrosolic acid (10) when one of the oxygen atoms of the nitroso groups forms an oxime (enolic isomer) and (iii) a dioxime (HON=C=NOH) of CO2 if a 1,3-hydrogen shift... 

Blinc and Iladzi (23a) have shown that this frequency, which lies at about 1650-1820 cm-1 in a series of afe-dioxime complexes, is more probably the in-plane O-H deformation frequency, and that the O-H stretching frequency lies in the range 2340-2380 cm-1 they find the out-of-plane O-H vibration between 860 and 930 cm-1. It seems likely that the hydrogen atoms do not lie directly between oxygen atoms, but it is still uncertain whether they are symmetrically disposed with respect to the oxygen atoms or not. 

Hydrogenation of a-hydroxyimino ketones and esters, and also of 1,2-dioximes, may lead to the formation of pyrazines. Tetraphenylpyrazine became the predominant product in the hydrogenation of benzil monoxime and dioxime over nickel catalyst in ether or alcohol at around 100°C. Thepyrazine was formed even in the hydrogenation... 

Hydrogenation of 1,4- and 1,5-dioximes tends to give pyrrolidines and piperidines, respectively. Thus, the hydrogenation of succindialdehyde oxime over Raney Ni in alcoholic ammonia, which did not occur at room temperature and 10 MPa H2, afforded only pyrrolidine on warming to 60°C.77... 

Fig. 11 Hydrogen-bonded tapes formed by l,l -bicyclohexylidene-4,4 -dione dioxime, based on Rl(6) motifs [94]...

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