6. by the process of claim 1 wherein, used solvent is a toluene. The purity of the dyestuff of Huo Deing is 96 to 97% (photometric measurements) in this way.The methylphenylamine that also contains 0.02-0.04% aniline and 0.004-0.006% in indigo. The objective of the invention is to study the method for the indigo efficient and cost-effective of a kind of purifying, not have or not have at least basically aromatic amine and other impurity in this dyestuff that obtains. PIGMENTS; MORDANTS; LAKES, Dystar Textilfarben GmbH & Co Dutschland K G, Ludwigshafen, Federal Republic of Germany, STAFFAN WEARING TEXTILE FIBERS CO., LTD. GERMANY, FORMER OWNER: DYSTAR TEXTILFARBEN GMBH + CO DUTSCHLAND K G, A kind of method reclaiming mixed alkali liquor from indigo aftertreatment washing process, Conditioning of 4,4',7,7'- Tetrachlorothioindigo, The preparation method of indigo compound, Process for the production of indigo compounds, Method for recovering fluorinated carboxylic acid, The extraction of citric acid from fermentation broth using a solution of a tertiary amine, Removal of organic iodine compounds from carbonylation products of methanol, methyl acetate and dimethyl ether, Process for preparing fluorocarboxylic acids, A process and extractant composition for extracting acids, Method for extracting unsaponifiable matters from vegetable oils using chloro-1-butane, composition containing said unsaponifiable matters, Process for obtaining an organic acid from an organic acid ammonium salt, an organic acid amide, or an alkylamine organic acid complex, Process for treatment of adipic acid mother liquor, Process for preparing carboxylic acids and derivatives thereof, Lactic acid production, separation and/or recovery process, Isolation of carboxylic acids from fermentation broth, Method for isolating a carboxylic acid from an aqueous solution, Process for producing glycolide and glycolic acid oligomer for production of glycolide, Butanol recovery from fermentations by liquid-liquid extraction and membrane solvent extraction, Production of methyl ester or ethyl ester of trifluoroacetic acid and chlorodifluoroacetic acid, Method for extracting a macrolide from biomatter, Process for separating impurities from aqueous solution of crude ethanol. Synthesis of Indigo 1) On a watchglass, weigh 1.0 g of 2-nitrobenzaldehyde and transfer it to a 100 mL beaker. Hofmann showed that toluidine (CH3C6H4NH2) must be present to produce these dyes. More than 100 of each are listed in the Colour Index, so the number of possible combinations is great, but the number of those known to give useful colorants with adequate fastness is much smaller. Standardization tests and identification of dyes. Heating phthalic anhydride with resorcinol (1,3-dihydroxybenzene) produced a yellow compound he named fluorescein, because aqueous solutions show an intense fluorescence. The chemical synthesis of indigo dyes starting with petrochemical resources such as aniline utilizes hazardous chemicals such as catalysts and reducing agents used for its synthesis and dyeing process must be addressed. ScienceDirect ® is a registered trademark of Elsevier B.V. ScienceDirect ® is a registered trademark of Elsevier B.V. A review of recent progress in the synthesis of bio-indigoids and their biologically assisted end-use applications. In the preferred embodiment of the inventive method, the alkali aqueous solution of about 85 ℃ hydroxyl indole acid salt of obtaining during the indigo preparation is covered with nitrogen immediately, cooling (about 5-15 minute) is extracted with inert organic solvent in 5-10 minute in 65 ℃ then to 65 ℃ as early as possible, and phase ratio is 1: 0.5.After being separated, the hydroxyl indole acid salt solution atmospheric oxidation that will extract by conventional process obtains indigoly, and its purity is 96-97%. Some thiazines—namely, those with X = NR but lacking the ―N(CH3)2 groups—are antihistamines. A process for the preparation of purified indigo comprises extracting the aqueous alkaline indoxylate solution arising from the synthesis with an inert water-insoluble solvent in the absence of oxygen before oxidizing the indoxylate solution to give indigo. Prove: the optimum extracting method that is present in the impurity in the hydroxyl indole acid salt solution is: the ratio (phase ratio) of hydroxyl indole acid salt solution and organic solvent (weight) is 1: 0.1 to 1: 1, preferred 1: 0.2 to 1: 0.6. The dye was also known to ancient civilizations in Mesopotamia, Egypt, Britain, Mesoamerica, Peru, Iran, and Africa. Baeyer–Drewson indigo synthesis. Basic Red 9, and a homolog having a methyl group (―CH3) ortho to one of the amino groups (―NH2); its classical name is magenta (C.I. Six printed magazine issues delivered to your door. Because these purification process even after the dyestuff fine grinding, still can not make the concentration of aniline and methylphenylamine obtain to reduce, and therefore must suppose that these impurity are to be included in securely among the indigo crystalline structure. Since the process was done at ice temperature, some dyes were called ice colours. The recognition of carbon’s tetravalency (1858) and the structure for benzene (1865) proposed by the German chemist Friedrich August Kekulé led to the structural elucidation of aromatic compounds and the rational development of the dye industry. A weekly e-bulletin delivered to your inbox with all the latest developments, Unlimited access to our daily news website, including premium content, Digitised versions of every printed issue we’ve published since February 2007. When indigo is decomposed simple compounds like aniline and picric acid are produced . By signing up for this email, you are agreeing to news, offers, and information from Encyclopaedia Britannica. ... For Synthetic Production of Indigo Dye. Indigo was known throughout the ancient world for its ability to color fabrics a deep blue. 2. by the process of claim 1 wherein, the extraction of hydroxyl indole acid salt solution is carried out under 55-75 ℃. In a careful study, the British chemist Edward Chambers Nicholson showed that pure aniline produced no dye, a fact also discovered at a Ciba plant in Basel, Switzerland, that was forced to close because the aniline imported from France no longer gave satisfactory yields. Indigo dye is an organic compound with a distinctive blue color. The oldest known fabric dyed indigo, dated to 6,000 years ago was discovered in Huaca Prieta, Peru. Overview of various indigoids synthetic engineering. Indigo was also cultivated in India, which was also the earliest major center for its production and processing. Indigo is not considered to be hazardous but it will stain skin and clothes. Indigo is one of the oldest known dyes and is a major component of dyes used for coloring jeans their classical blue hue. For the formation (I) that prevents known indigo red in the document (it is that self condensation by hydroxyl indole acid salt produces, thereby has reduced indigo quality and productive rate), generally be at 55-75 ℃ with the leaching process of organic solvent, preferably carry out about 65 ℃. Founded in 2006, Ecotextile News is the environmental magazine for the global textile and fashion industries and provides unrivalled daily coverage, comment and expertise in both print and online formats. The indigo aniline of 0.04-0.06% and 0.01% the methylphenylamine of containing that obtains. Exclusive discounts on MCL News & Media reports and magazines. Be on the lookout for your Britannica newsletter to get trusted stories delivered right to your inbox. While most substituents act as auxochromes, sulfonates are present only to increase the solubility of the dye, which is also improved by amino groups, hydrochlorides thereof, and hydroxyl groups. with date before 31.12.1992 and still valid on 11.12.2001 (patent law change 1993), Transfer of patent application or patent right or utility model, Termination of patent right due to non-payment of annual fee. Tetrabromofluorescein, or eosin, is a red dye used for paper, inks, and cosmetics; its tetraiodo analog, erythrosine, is a red food dye (see below Food dyes). Attempt to use known method, for example washing or stir with diluted acid, vapor distillation or remove aromatic amine in indigo with methods such as organic solvent extraction is not still achieved success, so far even dyestuff is through the grinding of very fine. This video explains Conventional and Greener route to synthesize Indigo dye. Undertaken by embodiment 1 program, but the toluene that is used to extract the indolic acid salts solution is 250 parts. adrenochrome, DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR, ORGANIC DYES OR CLOSELY-RELATED COMPOUNDS FOR PRODUCING DYES, e.g. History • Until the late 19th century, indigo was extracted from plants such as the Indian bean plant Indigofera tinctoria. Aniline content in the dyestuff was 0.02 to 0.04% (by weight), and methylphenylamine content was<0.01% (by weight). Related compounds, used primarily as pigments, span the colour range from blue to yellow.