- Method of preparing solvent red 24
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The invention discloses a method of preparing solvent red 24. The method comprises the steps of: feeding ortho-toluidine and methanol into a reactor, dropwise adding 30wt% of hydrochloric acid at 20-25 DEG C, cooling to 2-5 DEG C, dropwise adding 40wt% of sodium nitrite solution, performing thermal insulation for 3h, heating to a room temperature for thermal insulation for 2h, adding soft water, performing stirring and filtering, washing till a pH (potential of hydrogen) of filtrate is neutral, performing drying, feeding ortho-toluidine, the soft water and a single coupling material into the reactor, dropwise adding 30wt% of hydrochloric acid at 20-25 DEG C, cooling to 2-5 DEG C, dropwise adding 20wt% of sodium nitrite solution, performing thermal insulation for 4h, dropwise adding a mixedsolution of 2-naphthol and 5% alkaline liquor at 2-5 DEG C, performing thermal insulation for 2h, regulating the pH, performing thermal insulation for 5h, re-measuring the pH, performing filtering, and repeatedly cleaning and drying a filter cake. According to the method, reaction time is shortened; a reaction is relatively thorough; a product yield is increased by approximately 30%; almost no byproduct is generated; and a product is excellent in color light and strength.
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Paragraph 0015; 0019; 0022; 0025; 0026; 0027; 0028
(2018/11/03)
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- Synthesis and properties of amphiphilic photoresponsive gelators for aromatic solvents
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A sugar-based photoresponsive supergelator, N-glycosylazobenzene that shows selective gelation of aromatic solvents is described. The partial trans - cis isomerization of the azobenzene moiety allows photoinduced chopping of the entangled gel fibers to short fibers, resulting in controlled fiber length and gel - sol transition. The gelator is useful for the selective removal of toxic aromatic solvents from water.
- Rajaganesh, Ramanathan,Gopal, Anesh,Mohan Das, Thangamuthu,Ajayaghosh, Ayyappanpillai
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supporting information; experimental part
p. 748 - 751
(2012/03/26)
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- Azo compounds reducing formation and toxicity of amyloid beta aggregation intermediates
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The present invention relates to compounds suitable as modulators of protein misfolding and/or protein aggregation. The compounds are particularly suitable as inhibitors of amyloid aggregate formation and/or modulators of amyloid surface properties, and/or as activators of degradation or reduction of amyloid aggregates.
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- Azonium-ammonium tautomerism and inclusion complexation of 4-amino-2', 3-dimethylazobenzene
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The spectral characteristics of 4-amino-2',3-dimethylazobenzene (GBC), 4-aminoazobenzene (AAB) and azobenzene (AB) have been studied in various solvents, varying hydrogen ion concentrations and in β-cyclodextrin (β-CD). The inclusion complexes of GBC, AAB and AB with β-CD have been analysed by UV-visible, fiuorometry, FT-IR,1H NMR, SEM and Cache-DFT methods. The solvent study shows that the azo form is present only in GBC and AAB molecules. No significant spectral difference is observed in GBC indicating that the presence of two methyl groups does not effectively change the spectral behaviour as compared to that of AAB. In acid solutions, unusual red shift is observed in the monocation suggesting that the azonium-ammonium tautomer is present in both molecules. The absorption maximum at ~500 nm, is due to the azonium cation while that at ~320 nm originates from the ammonium cation. In β-CD solutions, the increase in the fluorescence intensity and large bathochromic shift in S1 state indicates that both GBC and AAB form 2:2 inclusion complex, whereas AB forms 1:1 inclusion complex. Also, head-to-head dimer is formed in both the aminoazobenzene compounds.
- Prabhu, A. Antony Muthu,Venkatesh,Sankaranarayanan,Siva,Rajendiran
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experimental part
p. 407 - 417
(2011/01/09)
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- Synthesis of deuterium-labeled azo dyes of the Sudan family
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Carcinogenic amines are formed in vivo during the metabolism of Sudan azo dyes. The identification and assay of these polluting agents requires the availability of deuterated analogues. Accordingly, two series of derivatives labeled on the phenylazo and naphthol moieties were synthesized. The new compounds were obtained in satisfactory chemical yields and with an excellent degree of labeling. The structures were confirmed by 1H NMR spectroscopy and high-resolution mass spectrometry. Georg Thieme Verlag Stuttgart.
- De Nino, Antonio,Di Donna, Leonardo,Maiuolo, Loredana,Mazzotti, Fabio,Sindona, Giovanni
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p. 459 - 463
(2008/09/20)
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- Water-soluble copper salts
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An improved process for preparing water-soluble copper salts of carboxylic acids is described. More particularly, the improved process comprises the steps of (A) providing a mixture comprising (A-1) as a copper source, copper metal, a copper oxide or mixtures thereof, (A-2) at least one organic monocarboxylic acid containing about 10 to about 30 carbon atoms, (A-3) at least one alkanolamine compound characterized by the formula wherein R1 is a hydroxyalkyl group and R2 may be hydrogen or a hydroxyalkyl group, and (A-4) water, (B) treating the mixture with oxygen at a temperature up to about the reflux temperature of the mixture until the desired water-soluble copper salt is obtained, and (C) recovering the copper salt as an aqueous solution. The mixture (A) can be modified to include one or more dyes to produce colored solutions of the water-soluble metal salts. The water-soluble copper salts prepared in accordance with the method of the invention are useful in a variety of applications, particularly as a preservative for wood. The invention also relates to wood which has been treated with the water-soluble copper salts of the present invention.
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