Cyanine dyes from 2-methyl-4,5,6,7-tetrafluorobenzimidazole derivatives

1-Ethyl-2-methyl-4,5,6,7-tetrafluorobenzimidazole was synthesized, and symmetrical and unsymmetrical imidacarbocyanines and merocyanines that are derivatives of Nethylrhodanine were synthesized from it. It was established that complete replacement of the hydrogen atoms in the benzene ring of benzimidazole by fluorine leads to a decrease in the basicity of the imidacarbocyanine and a hypsochromic shift of the absorption maximum in series of imidacarbo- and imidadimethylidyne-merocyanines.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1675–1679, December, 1981.     

New aminoalkyl and vinyl derivatives of pyridine and quinoline

New bases have been obtained by the Mannich reaction from 2-methyl-5-vinylpyridine and from 2,4-dimethylquinoline. Decomposition of quaternary salts of these bases has yielded previously unknown vinyl derivatives of pyridine and quinoline.     

Synthesis of quinoline vinyl derivatives by the Mannich reaction

Aminomethylation of quinaldine and lepidine is investigated. Decomposition of quaternary salts of Mannich bases gives 2- and 4-vinylquinoline.     

Cyanine dyes based on 2-phenyl-3,4-dimethyl-5,6-benzoquinoline

It is shown that the only product in the condensation of benzylidene-2-naphthylamine with methyl ethyl ketone is 2-phenyl-3,4-dimethyl-5,6-benzoquinoline, on the basis of the quaternary salt of which cyanine dyes were synthesized.     

Cyanine dyes based on the acid dichlorides of o- and p-carboxyphenylazochloroacetic acids

Cyanine dyes that contain chlorine, an azo group, and a phenyl ring in the conjugation chain have been synthesized for the first time.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1048–1049, August, 1971.     

Cyanine dyes from derivatives of 4-, 5-, and 6-trifluoromethylindolenines

The synthesis of 2,3-dimethyl-5- and -6-trifluoromethylindoles and 2,3,3-trimethyl-4-, -5-, and -6-trifluoromethylindolenines, from which quaternary salts, as well as indocarbo- and di- and tricarbocyanine dyes were obtained, is described. The effect of the introduction of a trifluoromethyl group in the 4, 5, and 6 positions on the color of the indocyanine dyes is examined.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 47–51, January, 1982.     

Cyanine dyes from thiazolomorpholinium and thiazolodihydrothiazinium salts

Cyanine dyes have been synthesized from previously unknown thiazolo [3, 2-c]morpholinium and thiazolo[3, 2-c]dihydrothiazinium salts, and their absorption spectra have been determined.     

Natural dyes based on chlorophyll and protoporphyrin derivatives

The utility of natural dyes (chlorophyll, protoporphyrin, and their derivatives) as ecologically pure new-generation dyes that are safer than common synthetic arene-based dyes is discussed. New dyes were obtained from chlorophyll and protoporphyrin derivatives such as pheophorbide (a+b), chlorin e₆, 6-N-(2-aminoethylamido)chlorin e₆ dimethyl ester, and 6-N-(2-aminoethylamido)deuteroporphyrin methyl ester and tested in coloration of wool, cotton, and acetate fibers.     

Cyanine dyes containing N-substituted azaaromatic moieties

Syntheses and properties of cyanine dyes bearing N-substituted pyridine and quinoline rings including cationic cyanines and merocyanines are reviewed.Institute of Chemistry, Pedagogical University al. Armii Krajowej 13/15 42-201 Czestochowa, Poland. Published in Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 882–898, July, 1995. Original article submitted March 6, 1995     

Liquid-crystalline quinoline derivatives

A number of novel liquid crystals have been synthesized. 2-Phenylquinolines with alkyl or alkoxyl substituents in positions 6 and 4' show a texture typical of nematic mesophases and are characterized by a greater thermal stability than Schiff bases bearing the same substituents. The possibility of lowering the melting temperatures by means of eutectic mixtures is discussed.     

Investigation of quinoline derivatives

The dehydrogenation of mononitro-1,2,3,4-tetrahydroquinolines and several of their N-acyl derivatives to the corresponding aminoquinolines was accomplished with various dehydrogenating agents. The maximum yields of aminoquino lines (15–20%) can be obtained when palladium on carbon is used as the dehydrogenating agent.See [1] for communication I.DeceasedTranslated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 103—104, January, 1972     

Syntheses of quinoline derivatives

In order to study the relationship between structure and biological activity we have synthesized 5-alkoxymethyl- and 5-aryloxymethyl-7-bromo-8-quinolinols.For part II, see [1].     

Investigation of quinoline derivatives

Some dinitro derivatives of 1,2,3,4-tetrahydroquinoline and its N-acyl analogs were synthesized. The structures of the dinitro isomers obtained were confirmed by NMR, UV, and IR spectroscopic data.See [1] for communication II.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 80–83, January, 1973.     

Quinaldine derivatives with fluorine-containing substituents and cyanine dyes based on them

Condensation of fluorine-containing anilines with paraldehyde gave quinaldine derivatives with CF₃, CF₃S, and CF₃SO₂ groups in the 6 position, from which carbocyanine, merocyanine, and styryl dyes were synthesized. Fluorine-containing groups lower the basicity of quinaldine by 0.7–2.0 pK_a units and lead to deepening of the color of the dyes.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 76–78, January, 1978.     

Synthesis and use of ecologically pure metal-containing dyes based on chlorophyll derivatives

The problem of the use of a natural pigment, chlorophyll, as ecologically pure dye for textile fibers is discussed. The physicochemical principles of the synthesis of metalocontaining compounds based on chlorophyll derivatives used for development of chlorophyll and porphyrin dyes of new generation, which are more ecologically safe than the arene-based dyes.     

Styryl derivatives of quinoline N-oxide

A new method has been developed for the synthesis of hitherto unknown styryl derivatives of quinoline N-oxide. Electron spectroscopy has shown the occurrence of intramolecular charge transfer processes in these compounds.Petrozavodsk State University, Petrozavodsk 185640. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 518–521, April, 1995. Original article submitted March 14, 1995.     

Synthesis and spectral properties of merocyanine dyes based on fluorene and its derivatives

The di-, tetra- and hexamethine merocyaninyes, the derivatives of fluorene, diphenyl 9H-fluorene-2,7-disulfonate, and bis(2,2,3,3,4,4,5,5-octafluoropentyl) 9H-fluorene-2,7-disulfonate, as well as the derivatives of the heterocycles of moderate (indolylidene and benzotiazolylidene), weak (benzo[c,d]indolylidene and 2,6-diphenylpyrane) and strong (2,6-diphenylpyridine) electron-donor properties were synthesized and their absorption spectra in solvents of different polarity were studied. The quantum-chemical analysis of electronic structure of the synthesized merocyanines was performed and the types of electronic transitions in them were found by the DFT and TDDFT methods with the B3LYP/6-31G(d,p) basis.     

Efficient and selective synthesis of quinoline derivatives

The bromination reaction of 1,2,3,4-tetrahydroquinoline (7) was investigated by NBS and molecular bromine. One-pot synthesis is described for synthetically valuable 4,6,8-tribromoquinoline (3) and 6,8-dibromo-1,2,3,4-tetrahydroquinoline (6) on bromination of 1,2,3,4-tetrahydroquinoline (7) in efficient yields (75 and 90%, respectively). 6-Bromo- (4) and 6,8-dibromo-1,2,3,4-tetrahydroquinolines (6) were converted to 6-bromo- (1) and 6,8-dibromo quinolines (2), respectively, by aromatization with DDQ in 83 and 77% yields, respectively. Several novel trisubstituted quinoline derivatives were efficiently prepared via lithium-halogen exchange reactions of tribromide 3. Treatment of 4,6,8-tribromoquinoline with BuLi followed by quenching with electrophiles [Si(CH₃)₃Cl, S₂(CH₃)₂, I₂] regioselectively proceeded at C-4 and C-8 sites and afforded corresponding 4,8-disubstituted-6-bromoquinolines. Similarly, lithiation of tribromide 3 followed by addition of water to the intermediate produced 6-bromoquinoline in 65% yield. Copper-induced nucleophilic substitution of tribromide 3 with NaOMe afforded 4,6,8-trimethoxyquinoline (17) in 60% yield.     

Disperse dyes based on 2-aminothiazole derivatives for cellulose triacetate fabric

A range of azo disperse dyes was prepared by coupling diazotized 2-amino-4-(p-nitrophenyl)-5-nitrothiazole with various substituted arylamines. Spectral properties in the infrared and visible range of the dyes obtained were investigated. All the dyes, when applied on cellulose triacetate fabric as 2% shade, showed fairly good to very good light fastness and very good to excellent fastness to washing, perspiration, rubbing and sublimation. All the dyes gave a wide range of reddish brown to indigo shades with very good depth and levelness on fabric. The purity of dyes was checked by thin layer chromatography. The percentage dyebath exhaustion and fixation on fabric was reasonably good and acceptable.