ChemInform Abstract: STUDY OF THE AMINOFORMYLATION OF UNSATURATED ALDEHYDES, 2‐ALKOXY ALDEHYDES, AND THEIR ALICYCLIC ACETALS AND KETONES

Makin, S. M.; Boiko, I. I.; Shavrygina, O. A.

doi:10.1002/chin.197738128

Cited by 4 publications

(4 citation statements)

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“…Compounds 2, 3, 5-8, 9-Cl, and 10-Cl were obtained by using the published procedures [4,[12][13][14][15]. All new compounds had no defined mp decomposing above 200 °C.…”

Section: Methodsmentioning

confidence: 99%

Water‐soluble pH‐sensitive 2,6‐bis(substituted ethylidene)‐cyclohexanone/hydroxy cyanine dyes that absorb in the visible/near‐infrared regions

Strękowski

Mason

Say

et al. 2004

Journal of Heterocyclic Chem

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Three methods were used to synthesize a series of the title compounds. The ketones absorb in the visible region, and upon protonation (pH<6) they are converted to hydroxy-substituted heptamethine cyanines that show an intense absorption in the near-infrared region (>700 nm). The conversion is reversible and depends solely on pH conditions. J. Heterocyclic Chem., 41, 227 (2004).A decade ago we reported for the first time a novel pHsensitive dye system 1=O/1-OH shown in equation 1 [1]. Ketone 1=O exhibits absorption in the visible region (λ max = 535 nm), and upon protonation it is transformed into hydroxy cyanine 1-OH with an intense absorption in the n e a r-infrared region (λ m a x = 709 nm). This change is reversible and depends solely on pH conditions. A related dye (not shown) has been described by us more recently [2]. The search for new pH-sensitive dyes that absorb in the near-infrared region of the electromagnetic spectrum (>650 nm) has been stimulated by potential application of such indicators in bioanalytical chemistry. When complexed or covalently attached to a protein, the pH-sensitive label can act as a pH-dependent reporter molecule in a complex biological material by using non-invasive spectroscopic detection. The direct spectral measurements are possible because few natural products show absorption above 650 nm and, as a result, any biological medium is extensively penetrated by near-infrared radiation [3]. Recently, covalent and non-covalent labeling of biological macromolecules with a near-infrared chromophore has become a firmly established trend in bioanalytical research [3][4][5][6].Due to their limited solubility, the two pH-sensitive dye systems mentioned above have found little application. In continuation of our research we now report for the first time the synthesis of a series of ketone/cyanine compounds that are water soluble. The previous chemistry [1,2] is evaluated, and an improved synthetic methodology is presented.The structures of new pH-sensitive compounds are given in Scheme 1. For the sake of clarity of presentation, only the cyanine forms (9-OH -12-OH, 15-OH) are shown. As can be seen, all these dyes are N-substituted with hydrophilic sulfoalkyl groups, additional two sulfo groups are attached to the aromatic subunits of 1 0 -O H, and an additional carboxylic acid function is present in 15-OH. Chloro cyanines 9-Cl -13-Cl served as precursors to the final products. The cyanines 9-Cl -13-Cl were efficiently synthesized by condensation of indolium derivatives 2-6 with Vilsmeier-Haack reagents 7 or 8. This is a classical preparation that is conveniently conducted in ethanol in the presence of sodium acetate as a base [7]. The conversion of substrates 9-Cl -13-Cl to the corresponding pH-sensitive dyes is summarized in Table 1 and discussed as follows.The Sodium-Acetate Method.

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“…Compounds 2, 3, 5-8, 9-Cl, and 10-Cl were obtained by using the published procedures [4,[12][13][14][15]. All new compounds had no defined mp decomposing above 200 °C.…”

Section: Methodsmentioning

confidence: 99%

Water‐soluble pH‐sensitive 2,6‐bis(substituted ethylidene)‐cyclohexanone/hydroxy cyanine dyes that absorb in the visible/near‐infrared regions

Strękowski

Mason

Say

et al. 2004

Journal of Heterocyclic Chem

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“…For instance, introduction of a rigid chlorocyclohexenyl ring in the methine chain can greatly improve the stability and the fluorescence quantum yields of cyanine dyes. [36][37][38][39] Peng's group first reported that tricarbocyanines with amine substituted at the central position of the polymethine bridge bear larger Stokes shifts than nonsubstituted and oxygen/ sulfur-substituted tricarbocyanines, owing to intramolecular charge transfer (ICT). 40,41 The large Stokes shift nature of amine-substituted tricarbocyanines renders them useful as NIR platforms for development of a diverse array of NIR fluorescent probes.…”

Section: Kaibo Zhengmentioning

confidence: 99%

Far-red to near infrared analyte-responsive fluorescent probes based on organic fluorophore platforms for fluorescence imaging

et al. 2013

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The long wavelength (far-red to NIR) analyte-responsive fluorescent probes are advantageous for in vivo bioimaging because of minimum photo-damage to biological samples, deep tissue penetration, and minimum interference from background auto-fluorescence by biomolecules in the living systems. Thus, great interest in the development of new long wavelength analyte-responsive fluorescent probes has emerged in recent years. This review highlights the advances in the development of far-red to NIR fluorescent probes since 2000, and the probes are classified according to their organic dye platforms into various categories, including cyanines, rhodamine analogues, BODIPYs, squaraines, and other types (240 references).

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“…A bis-anilinium derivative of the bis-aldehyde 11 [15] (27, structure in Scheme 3) is normally used in the synthesis of cyanine dyes by the reaction with methyl-substituted cationic heterocycles. The anilinium derivative 27 is more stable than the parent compound 11 and is easily purified by crystallization.…”

Section: Resultsmentioning

confidence: 99%

Near‐infrared bis(indolium heptamethine cyanine) dyes with a spacer derived from oligo(ethylene glycol)

Wolińska

Henary

Paliakov

et al. 2009

Journal of Heterocyclic Chem

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ChemInform Abstract: STUDY OF THE AMINOFORMYLATION OF UNSATURATED ALDEHYDES, 2‐ALKOXY ALDEHYDES, AND THEIR ALICYCLIC ACETALS AND KETONES

Cited by 4 publications

References 0 publications

Water‐soluble pH‐sensitive 2,6‐bis(substituted ethylidene)‐cyclohexanone/hydroxy cyanine dyes that absorb in the visible/near‐infrared regions

Water‐soluble pH‐sensitive 2,6‐bis(substituted ethylidene)‐cyclohexanone/hydroxy cyanine dyes that absorb in the visible/near‐infrared regions

Far-red to near infrared analyte-responsive fluorescent probes based on organic fluorophore platforms for fluorescence imaging

Near‐infrared bis(indolium heptamethine cyanine) dyes with a spacer derived from oligo(ethylene glycol)

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