Moscow Institute of Foreign Languages

The synthesis of the first representative of diazo compounds in the dihydrosilaazaanthracene series and a spiro compound with dihydrosilaazaanthracene and azetidine fragments was realized.

3-Methyl-9-phenylethynyl-2-azafluoren-9-ol, 3-methyl-9-phenacylidene-2-azafluorene, and spiro compounds with 2-azafluorene, indan, pyrazoline, and cyclopropane fragments were obtained starting from 3-methyl-2-azafluorenone by successive transformations. Information regarding the spatial structures of the synthesized compounds was obtained.

The effect of the position of the nitro group on the character of the dissociative ionization of nitro-substituted dihydrosilaazaanthrones was studied. It was established that a change in the position of the nitro group in the molecule affects not only the probability of the occurrence of monotypic fragmentations but is also responsible for the development of new pathways of the fragmentation of the molecular ions. This makes it possible to identify the isomeric nitrodihydrosilaazaanthrones from their mass spectra.

The conversion of l,3-dimethyl-2,6-diphenyl-4-benzyl-4-piperidol and its N-unsubstituted analog by means of pyridine N-oxide to 3-methyl-2,6-diphenyl-4-benzylpyridine (I) is accompanied by the formation of l,2-diphenyl-l,2-bis(3'-methyl-2',6'-diphenyl-4'-pyridyl)ethane, which was obtained under the same conditions directly from y-benzyl-substituted pyridine I. The initial product in the catalytic dehydrocyclization of pyridine baseI is l,3-diphenylbenzo[g]isoquinoline, which is subsequently partially converted to 7-phenyl-8-azabenzo[a]fluoranthene. Spectral data for these heterocyclic compounds and the characteristics of the substances obtained by oxidation of them are presented.

1,2,5-Trimethyl-4-(9′-fluorenylidene)piperidine, which is formed by condensation of fluorene with 1,2,5-trimethyl-4-piperidone, is converted catalytically to 9(2′,5′-dimethyl-4′-pyridyl)fluorene, from which 2-methylpyrido[4,5-a]fluoranthene and its demethylated analog were obtained by catalytic dehydrocyclization. Oxidation of 9-(2′,5′-dimethy1-4′-pyridyl)fluorene gave 9-(2′,5′-dimethyl-4′-pyridyl)9-fluorenol and fluorene-9-spiro-4′-(6′-oxo-2′-carboxypyrido[4′,5′-c]-4′-6′-dihydrofuran). 6-Methyl-2-phenyl-7-(9′-fluorenyl)indolizine was synthesized by the Chichibabin method.

The entropy formulation of the three-parameter law of corresponding states in the Holleran-Hammes form, permitting the geometric correspondence of the form (anisotropy) of molecules to be taken into account, served as the basis for obtaining the dependence of the anisotropy of the component of the free energy G of a liquid crystal on the temperature T, pressure P, and relative anisotropy of b of the van der Waals repulsion parameter. An expression is derived for the functional G of a liquid crystal which is weakly inhomogeneous (over the molecular length), making it possible to find the spatial distribution not only for the directions of orientational order (director field) but also its magnitude (field of Tsvetkov parameter η). An appendix studies the dependence of the pitch of the spiral (helicoid) of a cholesteric liquid crystal (weakly doped nematic liquid crystal) on T, P, b, η, and the concentration of the active additive. The theoretical results obtained are compared with experiment.

Acylation of 3-methyl-2-azafluorene under various conditions yielded the enol forms of its (C(9) acyl derivatives, whereas the ketol form was also isolated in the case of the p-nitrobenzoyl derivative. The character of the compounds formed in the reaction of 3-methyl-2-azafluorene with benzoyl chloride and acetic anhydride is discussed.

In an investigation of the conditions for the formation of Schiff bases from 3-methyl-2-azafluorenone and arylamines it was shown that the use of boron trifluoride etherate as the catalyst insures the highest yields. The fundamental possibility of the preparation of Schiff bases by condensation of 3-methyl-2-azafluorene with p-nitrosodimethylaniline and subsequent reduction of the resulting oxazirane structure is demonstrated. The ratio of the cis and trans isomers of the resulting azomethines was established on the basis of PMR spectral data.