Studies on cyanine dyes II. Preparation of ferrocene cyanines

The condensation of ferrocene aldehyde with quaternary salts of 2-methyl heterocyclic compounds, in the presence of piperidine as a catalyst, afforded ferrocenyl cyanines. Interaction of ferrocene aldehyde with the non-quaternised heterocyclic compounds, in the presence of pyridine and sodium ethoxide as a condensing agent, afforded styryl ferrocenes.     

Studies on cyanine dyes: II. Preparation of ferrocene cyanines

The condensation of ferrocene aldehyde with quaternary salts of 2-methyl heterocyclic compounds, in the presence of piperidine as a catalyst, afforded ferrocenyl cyanines. Interaction of ferrocene aldehyde with the non-quaternised heterocyclic compounds, in the presence of pyridine and sodium ethoxide as a condensing agent, afforded styryl ferrocenes.     

Studies on cyanine dyes. III. Synthesis of 2-styryl-5-cyanonaphthoxazole cyanine dyes

New types of styryl cyanine dyes (V) containing two different heterocyclic nuclei were prepared through the reaction of 5-cyanonaphth[1,2-]-oxazole-2-carboxaldehyde (IV) with α-picoline and quinaldine ethiodides. Other styryl bases (III) were also obtained as reaction products between 2-methyl-5-cyanonaphth[1,2-d]oxazole (I) and aromatic aldehydes in the presence of anhydrous zinc chloride. Structural configurations of the synthesised compounds were identified by u.v. and i.r. spectra determination.     

Cyanine dyes from 4,5,10-trioxo- 1,2,3,4,5,10-hexahydro-benz[g]quinoline

Asymmetrical bis-styryl cyanine dyes ( IVa-f ) containing arylidene moieties were obtained through the interaction of 4,5,10-trioxo-1,2,3,4,5,10-hexahydrobenz[g]quinoline ( I ) with aromatic aldehydes followed by condensation with 2-methyl quaternary salts. In addition interaction of ( I ) with heterocyclic aldehydes, then condensation of the products ( IIIa, b ) with 2-methyl quaternary salts gave the asymmetrical bis-styryl cyanines ( Va-d ). Other symmetrical bis-styryl cyanines ( VIIIa-c ) were also obtained as reaction products between 3,4,5,10-tetra-oxo-1,2,3,4,5,10-hexahydrobenz[g]quinoline ( VII ) and two moles of 2-methyl quaternary salts. The new compounds were identified by i.r. spectra determination. Bactericidal activity of selected asymmetrical and symmetrical bis-styryl cyanines ( IVa-i, Va-d and VIIIa-c ) were tested against bacterial and fungal strains.     

Synthesis and antimicrobial activity of certain novel monomethine cyanine dyes

A series of novel monomethine cyanine dyes were synthesized by using 3-methyl-5-substituted-1-phenyl-pyrano[2,3-c]pyrazole derivatives 2a–c. Reaction of equimolar ratios of 2a–c with 2(4)-methyl heterocyclic quaternary salts afforded the corresponding monomethine cyanines 3a–c. Reaction of compound 5 with 2(4)-methyl heterocyclic quaternary salts gives monomethine 6a–c. Condensation reaction of equimolar ratios of compounds 7 and 9a,b with 2(4)-methyl heterocyclic quaternary salts afforded the corresponding monomethine cyanines 8a–c and 10a,b respectively. The new synthesized monomethine cyanine dyes were identified by elemental analyses, IR, ¹H-NMR and Ms spectral data. The electronic absorption spectra in ethanolic solution of novel monomethine cyanine dyes were measured and the antimicrobial activity of some selected monomethine cyanine dyes was discussed.     

Synthesis,spectral behaviour and biological activity of pyrazolo-pyrimidine cyanine dyes

New asymmetrical 2(4)-monomethine cyanine dyes (III_a-_c IV_a-_i), monomethine bases (V_a,b), dicationic cyanines (VIII_a__c, IX_a-_c) and styryl cyanines (XI_a-_b) incorporating N-phenyl-1-H-pyrazolo (3, 4-d) saturated or unsaturated pyrimidine were prepared. The new cyanines were identified by spectral determination. Bactericidal and fungicidal activity of selected cyanines (III_a-c, IV_a-i, V_a,bVIII_a-_c, IX_a-c and XI_a,b) were tested against bacterial and fungal strains.     

Synthesis, absorption characteristics and solvatochromism of some novel heterocyclic cyanine dyes

Novel heterocyclic monomethine, bis monomethine, trimethine and bis trimethine cyanine dyes incorporating benzo [2,3-b; , - ] bis furo [3,2-d] pyrazole nuclei were synthesised. The absorption characteristics of the prepared cyanines were studied and determined through measuring their electronic visible absorption spectra in 95% ethanol. The solvatochromism of some of the synthesised dyes was investigated.     

Methine chain substituted styryl cyanine dyes—part I

Twenty-seven styryl dyes having 1-naphthyl and 2-naphthyl substituents at the β-carbon atom (β- to the heterocyclic moiety) of the methine chain have been prepared by condensing p-diethylaminophenyl 2-naphthyl ketone, p-dimethylaminophenyl 1-naphthyl ketone and p-dimethylaminophenyl 2-naphthyl ketone with quaternised salts of variously substituted quinaldines and lepidine. The dyes obtained show hypsochromic shifts in absorption maxima compared with their analogues having no substituent in the methine chain wherever comparable data have been available in the literature. The photosensitisation properties of the dyes have also been studied.     

Studies on cyanine dyes. I. Synthesis of new oxacyanine dyes

Synthesis of new types of bisoxacyanine dyes covering styryl-, mero-, and methine cyanines was achieved by interaction of 2,6-dimethylbenzdioxazole 3,7-bis-ethyl iodide with active carbonyl components. These dyes showed high absorption spectral properties and were found to induce remarkable sensitisation effects when applied to silver halide emulsions.     

Synthesis of some new unsymmetrical aza-pyrazolomonomethine cyanine dyes

New aza-pyrazolomonomethine cyanine dyes IV and V have been prepared by the condensation of some nitroso compounds, namely p-nitroso-N,N′-dimethyl or diethyl aniline, α-nitroso-β-naphthol and β-nitroso-α-naphthoI, with known unsymmetrical pyrazolomonomethine cyanines II and III . The u.v. and visible spectra of all dyes prepared have been investigated.     

N-(1,1-dihydro)polyfluoroalkyl substituted triphenylmethane dyes

A number of new triarylmethane and styryl dyes with 1,1-dihydropolyfluoroalkyl groups at the nitrogen atoms have been prepared. We have studied the influence of polyfluoroalkyl groups on the colour of these triarylmethane and styryl dyes. The accumulation of N-polyfluoroalkyl radicals in the molecule of triarylmethane dyes exerts a hypsochromic shift of absorption maxima. The styryl dyes absorb at shorter wavelengths than the styryl dyes with dimethylamino groups. These demonstrate the lessening of the basicity of the nitrogen atom, bonded with the 1,1-dihydropolyfluoroalkyl radicals. Nevertheless, RNCH₂(CF₂CF₂)_nH groups show themselves in the triphenylmethane and styryl dyes as sufficiently strong auxochromes.     

Chromophoric chain β-aryl-substituted styryl cyanines: effect of substituents on visible absorption spectra and photosensitisation properties

A number of chromophoric chain β-aryl-substituted (CCBAS) styryl cyanines (hemicyanines) have been synthesised by condensing substituted quaternised quinaldine bases with substituted benzophenones, with a view to studying the effect of the aryl substituents on their visible absorption and silver halide photosensitisation properties.The dyes absorb at longer wavelengths than the unsubstituted analogues, showing uniform bathochromic shifts and extra-photosensitisation properties, which corroborate the authors' previous findings.Irrespective of the nature of the substituent attached to the chromophoric β-phenyl group, electron withdrawing and donating groups result in a bathochromic shift of the visible absorption band and extension of the extra-photosensitisation in most cases.     

Synthesis,spectral behaviour and biological activity of benzoxazonyl(quinoxalonyl)-benzfurano-(indolo)-quinoline apocyanine dyes

2[2-(benzoxazonyl / quinoxalonyl) - benzfurano (indolo)] - quinolinium -1 - ethiodide apocyanine dyes ( V _a-f and VI _a-f) were prepared, via interaction of 2-[2-(benzoxazonyl-/quinoxalonyl)-1,2-dibromoethenyl]-quinolinium-1-ethiodide ( IV _a,b) with the appropriate phenols/and or arylamines. The new cyanines were identified by spectral determination. Bactericidal and fungicidal activity of selected cyanines ( III _a,b, V _a, VI _a, VI _h, and VII ) were tested against bacterial and fungal strains.     

Synthese von 2-Heterocyclidenamino-1,3-diazatrimethincyaninen

Synthesis of 2-Heterocyclidenamino-1, 3-diaza-trimethincyanines The synthesis of 2-[3-methyl-benzthiazol-(1, 3)-inylidene-(2)-amino]- and of substituted 2-[1, 3-dithiolyliden-(2)-amino]-1, 3-diaza-trimethincyanines is described. The heterocyclic imines 1 react with phosgene or thiophosgene to the corresponding ureas 2 and thiureas 3 , respectively. Alkylation of 3 to the 2-alkylmercapto-1, 3-diaza-trimethincyanines 4 and subsequent condensation with imine 1 yields the dyes 5 . The chemical and spectroscopical data of cyanines 5 are described.     

The use of N-bridgehead heterocyclic indolizinium ylide in the synthesis of aza-cyanine dyes

The reaction of 3-methyl-8-oxime-1-phenylpyrazolo [4,5-d]indolizinium (bezoindolizinium) ylide iodide with 2(4)-methyl substituted heterocyclic quaternary salts give 8[2(4)]-aza-monomethine cyanine dyes. Meanwhile, the reaction with carbonyl compounds followed by reaction with 2-methyl quinolinium methiodide salts afforded 5(2)-aza-trimethine cyanine dyes. On the other hand, the reaction of 5-formyl-2-methyl-4-phenylpyrazolo[4,5-d]indolizinium (benzoindolizinium) ylide iodide with hydroxylamine hydrochloride followed by reaction with N-methyl heterocyclic quaternary salts afforded the corresponding 5[4(1)]-aza-dimethine cyanine dyes. These new compounds are characterized with elemental analyses, visible absorption, IR, ¹³C NMR, ¹H NMR and mass spectroscopy. The correlations between the structure and spectral properties of these dyes have been studied.     

Über die Synthese einiger Antipyrylmethine. I. Asymmetrische Antipyrylmethine

Synthesis of Some Antipyryl Methines. I. Asymmetrical Antipyryl Methines A new series of asymmetrical antipyryl dimethine cyanines 2–7 was synthesized, starting with antipyrine aldehyde 1 and methylcarbenium salts, and the color change of the dyes was investigated as a function of the carbene moiety.     

Synthesis of novel fluorescent styryl dyes based on the imidazo[1,2-a]pyridinium chromophore and their spectral-fluorescent properties in the presence of nucleic acids and proteins

The imidazo[1,2-a]pyridinium heterocyclic system was used to prepare styryl dyes. Improved synthetic methods were proposed for the parent imidazo[1,2-a]pyridines and their corresponding quaternary salts. The standard method for preparing styrylcyanines was modified for the synthesis of the target imidazo[1,2-a]pyridinium dyes. Spectral-luminescent properties of the obtained dyes in free state and in the presence of nucleic acids, BSA, and BSA/detergent system were studied. 7-[2-(4-Dihexylaminophenyl)-1-ethenyl]-2-(2,4-dimethoxyphenyl)-1-ethylimidazo[1,2-a]pyridin-1-ium iodide (SIP-8) containing C₆ aliphatic tails and 2,4-methoxy substituents in the 2-phenyl ring exhibited specificity to BSA.     

Novel substituted 2-acetamido thiophene-4-styryl disperse dyes

Ethyl 2-acetamido-3-cyano-5-carbethoxy thiophene-4-acetic acid ester has been synthesised by the Gewald reaction of diethyl acetonedicarboxylate, sulphur and malononitrile, followed by acetylation. A variety of aryl and hetaryl aldehydes were condensed with this thiophene derivative in refluxing DMF in the presence of piperidine to yield novel styryl dyes. The fluorescence in solution and dyeing properties of these styryl dyes on polyester were studied.     

Styryl dyes containing an aza-15-crown-5 macroheterocycle moiety

Seven new styryl dyes containing an aza-15-crown-5 moiety were synthesized and characterized by means of elemental analysis, m.p., UV, I R and ¹H-NMR spectra. The colour change in the presence of metal salts was investigated.     

Synthesis of some new disperse anthraquinone dyes

1-Hydroxy and/or 1-aminoanthraquinone was allowed to react with formaldehyde in an alkaline medium to give 1-hydroxy or 1-amino-2-hydroxymethyl-9,10-dihydroxy-anthracenes, which gave on air oxidation, hydroxymethylanthraquinone derivatives (I). Interaction of 1-amino-2-hydroxymethylanthraquinone or its 4-bromo derivative with carbonyl compounds in the presence of an acid catalyst gave (1,3)oxazine derivatives (II). The methylene group in position-2 of the (1,3)oxazine ring was found to be highly reactive and reacted with carbonyl compounds to form the corresponding arylidenes (III). Selective oxidation of dimethyl oxazine derivatives with SeO₂ gave the corresponding dialdehyde (IV), which interacted with aromatic amines to give the corresponding Schiff bases (V). The bromine atom in the 6-position of II was easily replaced by aromatic amines to give blue disperse dyes (VI).