A. V. Mazepa

Synthesis and Liquid Crystal Properties of 2,7-Dialkoxy-9-fluorenones

Abstract2,7-Dihydroxy-9-fluorenone was alkylated with alkyl halides in acetone in the presence of potassium carbonate to prepare 2,7-dialkoxy-9-fluorenones prone to mesomorphism. Mesomorphic properties are characteristic of the compounds containing in the alkoxyl chain from 5 to 14 carbon atoms. When slowly cooled, such compounds tend to vitrify in the liquid crystal phase.

Specific features of the reduction of disubstituted amide derivatives of p-tert -butylcalix[4]arene

Regardless of the reducing agent, the reduction at 25°C and higher of the amide groups in a large number of p-tert-butylcalix[4]arene derivatives containing amide fragments with different substituents on the nitrogen atoms was accompanied by hydrogenolysis of the C-N bond with formation of the corresponding O-(2-hydroxyethyl) calixarenes and by partial cleavage of the ether bond between the calixarene framework and the substituent to give compounds with a lower degree of substitution.

Synthesis of acridinyl- and fluorenylidenehydrazido derivatives of p-tert-Butylcalix[4]arene

Abstractp-tert-Butylcalix[4]arenes substituted at the lower rim by acetic acid hydrazide residues reacted with methoxy(ethoxy)acridine and fluoren-9-one derivatives to give a series of calixarenes containing N′-fluorenylidene- and N′-acridinylacetohydrazide residues. It was found that modification of the hydrazide moiety does not affect the conformation of the initial macroring and that it can lead in some cases to unsymmetrically substituted calixarenes.

Preparation and some physicochemical properties of benzylammonium sulfates

New method of preparation of multisubstituted benzylammonium cations via interaction in the SO2-L-H2O systems (L is benzylamine, α-phenylethylamine, N,N-dimethylbenzylamine, or dibenzylamine) has been developed. The products have been studied by X-ray diffraction, IR, Raman spectroscopy, and mass spectrometry.

Calix(4)arenes Containing Benzodiazepinone Fragments at the Lower Rim

A series of p-tert-butylcalix[4]arene derivatives containing 1,4(1,5)-benzodiazepinone fragments as substituents were prepared. The biological activity of the compounds, namely, their antispasmodic activity in mice, was evaluated by antagonism with a spasmodic agent, Corazol, upon transdermal administration. According to the data obtained, benzodiazepine derivatives of calixarenes show higher antispasmodic activity compared to 3-hydroxyphenazepam, taking into account their considerably higher molecular weight.

Tin(IV) complexes with 2-hydroxybenz-(2-hydroxynaphth)aldehyde picolinoylhydrazones (H2Ps, H2Pnf). Crystal structure of [SnCl3(Ps · H)] · CH3OH and [SnCl3(Pnf · H)] · CH3OH

The reactions of SnCl4 with picolinoylhydrazones of 2-hydroxybenz-(2-hydroxynaphth)aldehydes (H2Ps, H2Pnf) in CH3OH gave non-electrolyte complexes [SnCl3(Ps · H)] · CH3OH (I) and [SnCl3(Pnf · H)] · CH3OH (II). The imide form of the ligand coordinated to Sn(IV) through the azomethine nitrogen atom and oxyazine and oxy oxygen atoms was proved by UV/Vis, IR, and 1H NMR spectroscopy. The negative charge on the coordination unit thus arising is counterbalanced by the positive charge caused by the protonation of ligands at the pyridine nitrogen atom of the heterocycle. It was shown that dehydrochlorination of the complexes affords tin-containing species, which correlates with the presence of the corresponding peaks [SnCl2(Ps)]+ and [SnCl2(Pnf)]+ in their mass spectra. The molecular and crystal structures of complexes I and II were determined by X-ray diffraction.

p-tert-butylcalix[4]arenes containing azacrown ether substituents at the lower rim as potential polytopic receptors

A series of disubstituted p-tert-butylcalix[4]arenes with N-methoxycarbonylmonoazacrown ether and N-ethoxymonoazacrown ether residues at the lower rim has been prepared via the reaction of di(carboxymethoxy)-p-tert-butylcalix[4]arene with azacrown ethers and subsequent reduction of the resulting amide derivatives. Using UV titration and 1H NMR spectroscopy we have demonstrated the ability of the calixarene with two N-carbonylmonoaza-18-crown-6-ether substituents to form the 1:3 complexes with K+ and Na+ and the 1:2 complexes with Cs+, Sr2+, Cu2+, and Zn2+. The calixarene with two fragments of N-ethoxymonoazo-18-crown ether has formed binuclear complexes with alkali metals cations and mononuclear complexes with transition metals cations.

Synthesis of derivatives of p-tert-butylcalix[4]arene containing on lower rim fragments of 2-aminoalkylbenzimidazoles

Reactions of calix[4]arene carboxymethoxy derivatives with 2-aminoalkylbenzimidazoles in the presence of dicyclohexylcarbodiimide and hydroxybenzotriazole afforded a series of p-tert-butylcalix[4]arene derivatives containing on the lower rim N-(2-benzimidazolylalkyl)carbamoylmethoxy fragments. The reaction carried out in the absence of hydroxybenzOtriazole resulted in macrocycles containing one N-(2-benzimidazolylalkyl)carbamoyl fragment and a fragment of N-(acyl)dicyclohexylisourea.

Synthesis, spectral characteristics, and some properties of methylammonium sulfamate monohydrate. A new route to sulfamic acid derivatives

Redox transformations of the products of reactions of the CH3C(S)NH2-SO2-H2O system components yield methylammonium sulfamate monohydrate [CH3NH3]+[OSO2NH2]− · H2O and elemental sulfur. The synthesized compound was characterized by IR, 1H and 13C NMR, and mass spectroscopy and some of its properties were studied.

Synthesis, properties, and interaction with paraquat of new fluorenonocrownophanes containing a hydroquinone fragment

New crownophane family was synthesized containing fragments of 2,7-dioxyfluorenone and hydroquinone connected with residues of tri- and tetraethylene glycols. The formation of inclusion complexes of these ligands with paraquat was established by means of mass spectrometry (fast-atom bombardment), 1H NMR and electronic spectroscopy. The crownophane with a larger ring formed the more stable complex.