Synthesis and metallation of 2-(pyridyl)benzoic acids and ethyl 2-(pyridyl)benzoates: a new route to azafluorenones

The ring deprotonation of 2-(2- and 4-pyridyl)benzoic acids using lithium dialkylamides in THF at rt, and the in situ cyclization afforded 4- and 2-azafluorenones, respectively. 1-Azafluorenone was obtained from ethyl 2-(3-pyridyl)benzoate using a similar protocol.     

Synthesis and spectral and luminescent properties of 4-(5-aryloxazoyl-2)benzoic acids and their derivatives

Condensation of acid chloride of monomethyl terephtalate with -aminomethyl-arylketones and subsequent cyclodehydration of the resulting amides in sulfuric acid or phosphorus oxychloride give rise to methyl 4-(5-aryloxazolyl-2)benzoates which led to the corresponding acids, acid chlorides, and amides. The effect of electron-withdrawing groups on the spectral and luminescent properties, as well as on the stability of substituted 2,5-diaryloxazoles toward UV irradiation has been investigated.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1261–1264, September, 1986.     

New α-(pyrimid-4-ylamino)acids

The reaction of 4-methylthiothymine with amino acids has given -(2-hydroxy-5-methylpyrimid-4-ylamino)acids. Similarly, 4-methylthiouracil forms -(2-hydroxypyrimid-4-ylamino)acids the halogenation of which gives -(5-halogeno-2-hydroxypyrimid-4-ylamino)acids.     

Synthesis of (2-methylquinolin-4-ylsulfanyl)-substituted acetic and propionic acids and propionitriles

A procedure has been developed for the synthesis of (2-methylquinolin-4-ylsulfanyl)-substituted acetic and propionic acids and propionitriles having methyl, methoxy, or carboxy groups or halogen atom in position 6 or 8 of the quinoline ring via reactions of the corresponding substituted 2-methylquinoline-4-thiols with chloroacetic or acrylic acid and acrylonitrile.     

Synthesis and mesomorphic properties of n-alkyl 4-[4-(4-n-octyloxybenzyloxy-2,3,5,6-tetrafluorophenyl)ethynyl]benzoates

A new series of n-alkyl 4-[4-(4-n-octyloxybenzyloxy-2,3,5,6-tetrafluorophenyl)ethynyl)benzoates have been prepared. Polarizing microscopic textural observation shows that they are liquid crystals with nematic phase.     

The synthesis and mesomorphic properties of 4-n-alkoxyphenyl 4-[(4-n-alkoxy-2,3,5,6-tetrafluorophenyl)ethyl]benzoates

4-n-Alkoxyphenyl4-[(4-n-alkoxy-2,3,5,6-tetrafluorophenyl)ethynyl]benzoates (compound A) are synthesised by a convenient method. These compounds exhibit only enantiotropic nematic phases and have very high clearing points. These compounds (As) can be transformed into corresponding ethane derivatives, via hydrogenation using a palladium catalyst (Pd/C), which exhibit monotropic nematic phases. The effect of the ethylene bridge (–CH₂CH₂–) on the mesomorphic behaviour is discussed.     

Mesomorphic and fluorescence properties of methyl 4-(4-alkoxystyryl)benzoates

A series of methyl 4-(4-alkoxystyryl)benzoates was synthesised and studied for liquid crystalline and fluorescence properties. The peculiarity of the reaction scheme involved condensation between 4-alkoxybenzaldehyde and 4-(methoxycarbonyl)benzyltriphenyl phosphonium bromide in dichloromethane without any phase separation. The compounds were found thermally stable up to 200°C. The banded or arced focal-conic fan texture of CrE phase was exhibited on cooling the compounds (with chain length > C₄) below the SmA phase. It was observed that increasing chain length up to C₁₀ enhances mesophase stability. No LC behaviour was manifested by small (up to C₃) and branched small chain (up to C₄) members of the series.     

Mesomorphic properties of 4-(polyfluoroalkoxycarbonyl)phenyl 4-(4-n-heptoxy-2,3,5,6-tetrafluorophenyl)benzoates

A series of 4-(polyfluoroalkoxycarbonyl)phenyl 4-(4-n-heptoxy-2,3,5,6-tetrafluorophenyl)benzoates were synthesized and observed using DSC and optical polarizing microscopy. The results show that they are not mesogens. Their mesomorphic properties were compared with similar compounds containing no aromatic fluorine substituents.     

6-Hydroxyhexyl 4-(E)-4-alkoxy/halostyryl)benzoates: synthesis,characterisation and study of mesomorphic and fluorescent properties

Hydroxyhexyl esters of alkoxy and halostilbene carboxylic acids were prepared and studied for thermal, liquid crystalline and fluorescent properties. The decomposition temperatures were determined thermogravimetrically and the compounds were found stable at least up to 200°C. Differential scanning calorimetry (DSC) indicated two mesophases in alkoxystilbene caboxylates. The smectic nature of the liquid crystal (LC) compounds was identified from the optical textures and confirmed through X-ray diffraction (XRD) measurements, where SmA, SmB and CrE mesophases were observed. The compounds 3a-g and 3h-k show single absorption maxima in UV-visible spectra at around 338 and 322 nm, respectively. All the alkoxy compounds emit blue light in solution and in solid state in the wavelength range of 422–425 nm.     

Mesomorphic properties of 4-(polyfluoroalkoxycarbonyl)phenyl 4-(4-n-heptoxy-2,3,5,6-tetrafluorophenyl)benzoates

A series of 4-(polyfluoroalkoxycarbonyl)phenyl 4-(4-n-heptoxy-2,3,5,6-tetrafluorophenyl)benzoates were synthesized and observed using DSC and optical polarizing microscopy. The results show that they are not mesogens. Their mesomorphic properties were compared with similar compounds containing no aromatic fluorine substituents.     

Synthesis and mesomorphic properties of n-butyl-4- [4-((4-n-alkoxyl-tetrafluorophenyl)ethynyl)benzyloxy]benzoates

A homologous series of n-butyl-4-[4-((4-n-alkoxyl-tetrafluorophenyl)ethynyl)benzyloxy]benzoates have been synthesized.Their phase transition temperatures have also measured by polarizing textural observation and confirmed by DSC.     

Synthesis of 2-(4-chlorobenzylamino)-1-(4-nitrophenyl)ethanol and its chemical transformations

By the ring cleavage of p-nitrophenyloxirane with p-chlorobenzylamine the corresponding chlorobenzyl- and nitrophenyl-substituted aminoethanol was obtained that was brought into reactions of glycosylation, reduction and substitution aimed at the preparation and designing of new structures containing pharmacalogically active functional groups. Among the synthesized compounds a compound is revealed possessing moderately expressed antibacterial and antifungal activity.     

Synthesis of 1-(2-naphthyl)dihydro- and 1-(2-naphthyl)-2-thiodihydrouracils and their transformations

1-(2-Naphthyl)dihydro- and 1-(2-naphthyl)-2-thiodihydrouracils were obtained from N-(2-naphthyl)--alanine derivatives. The thiodihydrouracil was converted to a dihydrouracil. Bromination of 1-(2-naphthyl)dihydrouracil gave (1-bromonaphthyl)dihydrouracil. 1-(2-Naphthyl)-2-oxo-, 1-(2-naphthyl)-2-thio-. and 1-(1-bromo-2-naphthyl)-2-oxohexahydro-pyrimidines were obtained.Translated from Khimiya Geterotsiklicheskikh Soedinenii. No. 12, pp. 1695–1697, December, 1971.     

Synthesis of [(thiazol-2-ylamino)-methylene]bisphosphonic acids

A method for the synthesis of [(thiazol-2-ylamino)methylene]bisphosphonic acids from (aminomethylene)-bisphosphonic acid through 3-N-unsubstituted (thioureidomethylene)bisphosphonic acid was proposed.     

Preparative synthesis of 3- and 4-(3-alkoxy-4-acyloxyphenylmethylamino)benzoic acids

Reduction of 3- and 4-[(3-alkoxy-4-acyloxyphenyl)methylideneamino]benzoic acids (E isomers) with sodium triacetoxyhydridoborate in benzene gave the corresponding 3- and 4-(3-alkxy-4-acyloxyphenylmethyl) benzoic acids in preparative yields.     

Synthesis of S-[2-(4-Aminobenzenesulfonyl)ethyl] and S-[2-(3-Amino-4-methoxybenzenesulfonyl)ethyl] Thiosulfonates

Russian Journal of General Chemistry -     

有机锡4-(4-吡啶基甲基硫代)苯甲酸酯的合成、结构与生物活性研究(英文)

通过4-(4-吡啶基甲基硫代)苯甲酸与三苯基氧化锡以及三环己基氢氧化锡反应,合成了三苯基锡4-(4-吡啶基甲基硫代)苯甲酸酯(1)及三环己基锡4-(4-吡啶基甲基硫代)苯甲酸酯(2)。它们的结构通过红外,核磁以及X-射线单晶衍射分析得到确证。化合物1表现为一维链状结构,而化合物2通过分子间的O-H…O和O-H…N氢键形成二维网状结构。生物活性测试表明,这2个化合物具有较高的抗肿瘤活性。