Reactions of aliphatic ketones on zeolites

Reactions of some ketones (acetone, methyl ethyl ketone and diethyl ketone) on the H-form of ZSM-5, ZSM-11, mordenite and erionite have been studied in an integral reactor. At a reaction temperature of 300 or 350°C acetone is selectively transformed on all these zeolites into isobutene, while with higher ketones substantial amounts of aromatics are formed.

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(, ) - ZSM-5, ZSM-11 . , 300 350°C , .

     

Electroreductive crossed pinacol coupling of aromatic ketones with aliphatic ketones and aldehydes

The intermolecular crossed pinacol coupling of aromatic ketones with aliphatic aldehydes and ketones was effected by electroreduction in the presence of chlorotrimethylsilane. The best result was obtained using a Pb cathode in Bu₄NPF₆/THF. The electroreduction of aromatic 1,4-, 1,5-, and 1,6-diketones under the same conditions gave four-, five-, and six-membered 1,2-diols with trans-stereoselectivity, while the reduction of these diketones with TiCl₄-Zn produced the cis-isomers of the same intramolecular crossed pinacol coupling products predominantly.     

Reactions of organylthiochloroacetylenes with aliphatic diamines

Conclusions Depending on the length of the hydrocarbon chain of the amine, the reaction of organylthiochloroacetylenes with aliphatic primary diamines gives various nitrogen-containing heterocycles, namely, imidazolines, tetrahydro-1,3-diazepines, and hexahydro-1,3-diazocines.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 4, pp. 906–909, April, 1989.     

Reactions of 2-polyfluoroalkylchromones with aliphatic diamines

2-Polyfluoroalkylchromones react with aliphatic 1,2-diamines to give 2,3-dihydro-1H-1,4-diazepines. A similar reaction with 1,3-diaminopropane yieldsN,N′-trimethylenebis(2-hydroxyacetophenomines) as a result of scission of the original chromones. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 817–819, April, 1999.     

Reactions of tetrachloropyridazine with aliphatic nitrogen nucleophiles

Nucleophilic aromatic substitution reactions of tetrachloropyridazine with a series of aliphatic primary and secondary amines led selectively to products arising from replacement of chlorine at the 4‐position in all cases. The structures of the products were unambiguously confirmed by X‐ray crystallography. Substitution occurs at the most activated site para to ring nitrogen, despite the possible steric hindrance to substitution by adjacent chlorine atoms, reflecting the activating influence of ring nitrogen meta to the site of attack. N,N′‐Dimethylethylene diamine gave a mixture of [6,6] ring fused products following initial substitution at the 4‐position.     

Interactions of aliphatic β-amino-β-trifluoromethylvinyl ketones with ethylenediamine

The reactions of aliphatic β-amino-β-trifluoromethylvinyl ketones with an excess of ethylenediamine at room temperature afforded the corresponding 2,3-dihydro-1H-1,4-diazepines or substituted 2-acetonyl-2-trifluoromethylimidazolidines (the latter were obtained when the approach to the carbonyl group was sterically hindered). Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2305–2308, November, 1998.     

Reactions of 1,3,5-trinitrobenzene with primary aliphatic alcohols

Analysis of reactions of 1,3,5-trinitrobenzene (TNB) with alcoholates of primary aliphatic alcohols (substitution of the nitro group or generation of σ^H-complexes at the unsubstituted position of TNB) leads to the conclusion that high basicity of alcoholates (MeONa, EtONa) of unsubstituted primary alcohols promotes formation of σ^H-complexes, thus preventing nucleophilic substitution of a nitro group. Introduction of electron-withdrawing substitutes (R = HC≡C, H₂C = CH, pyridyl) into the alcohol molecule (RCH₂OH) reduces the basicity of their alcoholates which makes substitution of nitro groups possible aff ording the corresponding 1-alkoxy-3,5-dinitrobenzenes in the presence of K₂CO₃ in N-methylpyrrolidone at 80 °C.     

Reactions of 1-aryl-2,5-dimethylpyrroles with ketones

1-Aryl-2,5-dimethylpyrroles react with acyclic ketones with acid catalysis to give geminal di-2-pyrrolyl derivatives independently of the ratio of the reagents. The reaction of cyclohexanone and cycloheptanone occurs analogously with 21 ratio of pyrrole to ketone. With an excess of cyclohexanone a cycloheptanone 1-aryl-2,5-dimethyl-3,4-dicyclohexenylpyrroles and substituted 4,5,6,7,8,9-hexahydro-2H-azulene[1,2-c]pyrrol-4-spirocycloheptane are produced respectively.Institute of Organic Chemistry, Ukraine National Academy of Sciences, Kiev 253660; e-mail: dov@fosfor.kiev.ua. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1506–1511, November, 1999.     

Reactions of diorganoytterbium compounds with ketones and aldehydes

Reactions of the diorganolanthanoids R₂Yb (R = PhCC or C₆F₅) with aldehydes (R′CHO) and ketones (R′₂CO) (R = Me or Ph) followed by hydrolysis generally gives the alcohols RR′CH(OH) or RR′₂COH, but, with benzophenone, reduction giving benzopinacol either competes (R = PhCC) or is predominant (R = C₆F₅).     

Low-energy mass spectra of some aliphatic ketones

The charge exchange mass spectra of a selection of C₅-C₇ ketones have been measured using [CS₂]⁺˙, [COS]⁺˙ and [N₂O]_+. as reagent ions. The low energy charge exchange with [CS₂]⁺˙ or [COS]⁺˙ provides simple primary ion mass spectra, which readily permit structure elucidation in contrast to metastable ion spectra. In several cases, isomer distinction is easier from the charge exchange mass spectra than from the electron impact mass spectra. The energy transfer from [N₂O]⁺˙ is sufficiently high for complex spectra resembling electron impact mass spectra to be obtained.     

Reactions of the carbonate radical with aliphatic amines

Carbonate radicals react with aliphatic amines by a dual mechanism, viz. (i) hydrogen abstraction and (ii) electron transfer. The former is more probable with primary amines. Tertiary amines react via electron transfer. Both mechanisms may operate in secondary amines. Cyclic tertiary amines react with different rates and their relative reactivities are explained on the basis of the concept of Hoffmann's ‘through bond’ interaction.     

Reactions of aliphatic β-amino-β-(trichloromethyl)vinyl ketones with ethylenediamine. Synthesis and structures of 2-acetonylideneimidazolidines

Reactions of aliphatic β-amino-β-(trichloromethyl)vinyl ketones with an excess of ethyl-enediamine at room temperature afford substituted 2-acetonylideneimidazolidines. The structure of 2-pivaloylmethyleneimidazolidine was established by X-ray diffraction analysis.     

Dye-assisted chromatographic determination of aliphatic ketones and esters with brilliant green

Determinations of neutral nonchromophoric organic compounds by dye-assisted chromatography are extended to the determination of aliphatic ketones and esters by using reversed-phase conditions and a mobile phase containing Brilliant Green. Detection limits of 6–20 μg were obtained when a mobile phase containing 50% (v/v) methanol/water and 0.00010 M Brilliant Green was used with detection at 575 nm, and 0.5–2 μg with detection in the ultraviolet region. In the absence of dye the detection limits for several solutes were about four times higher than the corresponding values obtained with the dye. The dye was shown to form a dimer having a molar absorptivity two orders of magnitude smaller than that of the monomeric dye. Detection of non-chromophoric compounds is concluded to be due to the desorption of adsorbed dye by the analytes and the shift of the aggregation and hydration equilibria of the dye promoted by the organic solutes. The lowering of the capacity factors is interpreted in terms of the adsorption of dye by the column which reduces the hydrophobicity of the stationary phase.