Jinzong Yang

Dyeability of Polylactide Fabric with Hydrophobic Anthraquinone Dyes

The dyeability of polylactide fabric has been investigated with the substituted aminoanthraquinone hydrophobic dyes. Their application to the polylactide fabric led to good exhaustion values and good wash fastness between 4 and 5. Microscopic assessment of cross-sections of the dyed polylactide fibres confirmed that these dyes could penetrate into the fibres. The nature of the substituted amino groups showed little influence on the wash fastness, but clearly influenced the exhaustion and light fastness.

Synthesis and application of direct black dyes containing 4,4'-diaminodiphenyl sulfonamide

4, 4-Diaminodiphenyl sulfonamide and black dyes based on this intermediate were synthesised. When mixtures of the black dyes were used to dye silk, the blackness at 5% shade depth was C. I. Direct of Black 38. Their exhaustion and fastness to light and washing was better than that of C. I. Direct Black 38.

A Novel Approach to the Synthesis of 6-Amino-7-hydroxy- flavone

A novel approach to the synthesis of 6-amino-7-hydroxyflavone (1) is described. Reaction in acetone of 2,4-dihydroxy-5-nitroacetophenone and benzoyl chloride in the presence of potassium carbonate affords 3-benzoyl-7-hydroxy-6-nitroflavone, which is cleaved in 5% ethanolic potassium hydroxide to give 1-(2,4-dihydroxy-5-nitrophenyl)-3- phenyl-1,3-propanedione. The 1,3-diketone thus formed is then transformed into 7-hydroxy- 6-nitroflavone, followed by reduction to afford the title compound.

Electrochemical behaviour of azo dyes in acid/ethanol media

Abstract The electrochemical reduction of four azo dyes in acid media was studied by differential-pulse polarography, cyclic voltammetry and constant-potential coulometric methods. All of the electro-reductions of the azo groups are irreversible one-step and 4-electron reduction at pH 2 Bu-n) cause the azo groups to be more easily reduced than meta analogues. In compounds containing both azo and nitro groups, the azo group is reduced prior to the nitro group. The dyes are very useful in silver dye bleach photographic materials.

Optimisation of the synthesis of a water-soluble sulfur black dye

Abstract A water-soluble sulfur black dye containing carboxylic acid groups was prepared by reducing C.I. Sulfur Black 1 to its leuco form followed by reaction with chloroacetic acid. In conducting this reaction, variables studied included the order of adding reactants, the amount of Na2S and chloroacetic acid employed, and the time and temperature of the reaction. It was found that the carboxylic acid group content and reaction yield were maximized by controlling the amount of Na2S and chloroacetic acid employed, and by conducting the reaction for 2 h at 60xa0°C.

Metal phthalocyanine catalyzed oxidation of 4-nitrotoluene-2-sulfonic acid to 4,4′-dinitrostilbene-2, 2′-disulfonic acid

Abstract The effects of catalyst, alkali concentration, 4-nitrotoluene-2-sulfonic acid concentration, reaction temperature, and time of preparation of 4,4′-dinitrostilbene-2,2′-disulfonic acid from 4-nitrotoluene-2-sulfonic acid was investigated. The results showed that the liquid-phase oxidation of 4-nitrotoluene-2-sulfonic acid under optimal conditions gives 4,4′-dinitrostilbene-2,2′-disulfonic acid in 81.8% yield and in 96.7% purity.

A new fluorescent triphenodioxazine dye derived from 4-aminodiphenylamine

Abstract A new substituent triphenodioxazine compound containing the 3,10-di(N-benzoyl-N-phenyl) amino has been synthesized. The benzoyl groups were introduced into the molecule during the cyclization of the dianilide derived from 4-amino-diphenylamine in the presence of benzoyl chloride as ring closure agent. The absorption and fluorescence spectra of the dye were measured in five solvents and it was found that the fluorescence quantum yields, Stokes shifts and molar extinction coefficients varied linearly with E T of the solvents. When using p-toluene sulphonyl chloride as ring closure agent, p-toluene sulphonyl groups were also introduced.

Novel and Convenient One‐Pot Synthesis of 3‐Aroyl‐7‐Hydroxy‐6‐Nitroflavones

Abstract A novel and conveient one‐pot synthesis of 3‐aroyl‐7‐hydroxy‐6‐nitroflavones from 2′,4′‐dihydroxy‐5′‐nitroacetophenone and (substituted)benzoyl chlorides in refluxing dry acetone in the presence of anhydrous potassium carbonate was developed. The structures of the prepared compounds were characterized by IR, 1H NMR, and MS spectroscopy.

SYNTHESIS OF RING-A HYDROXYLATED FLAVONES BY SODIUM HYDROXIDE-CATALYZED CYCLIZATION OF 1,3-DIKETONES IN WATER

Flavonoids are a group of naturally occuning phenolic compounds widely distributed in the plant kingdom, the most abundant being the flavones. Members of the flavone class have been associated with a wide variety of biological properties, such as antitumor,l” biocida14 and activities. Owing to their importance, the synthesis of flavones and their derivatives have attracted the attention of chemists for many years. Currently there are a number of methods available to synthesize flavones,’ including the Allan-Robinson synthesis,* the Baker-Venkataraman method,’ synthesis from chalcones,I0 and synthesis via an intramolecular Wittig strategy,” etc. We would like to report herein that 6and 7-hydroxyflavones can be synthesized by sodium hydroxide-catalyzed cyclization of the corresponding 1,3-diketone in water, the procedures are shown in Schemes 1 and 2, respectively.