133-74-4Relevant articles and documents
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Suter,Weston
, p. 604 (1940)
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Development of an efficient ruthenium catalyzed synthetic process and mechanism for the facile conversion of benzothiazoles to orthanilic acids
Jagadeesh,Karthikeyan,Nithya,Sandhya, Y. Sree,Reddy, S. Sudhaker,Reddy, P. Pradeep Kumar,Kumar, M. Vinod,Charan, K.T. Prabhu,Narender,Bhagat
experimental part, p. 99 - 107 (2010/12/18)
Ruthenium-Schiff base complex catalyzed efficient protocol has been developed for the synthesis of orthanilic acids from benzothiazoles in good to excellent yields using N-haloamines. Hexa-coordinated ruthenium complex with Schiff base and triphenylphosphine ligands has been prepared and its catalytic function was invented for the synthesis of orthanilic acids. The synthetic process utilizes our efficient method for the selective and preferential oxidation of thiazole ring of benzothiazoles using N-haloamines without effecting phenyl ring. The detailed catalytic, mechanistic and kinetic investigations have been made for the synthetic reactions. Solvent isotope studies have been made in H2O-D2O and the reactions were carried out at different temperatures. Under the identical set of conditions, the kinetics of catalyzed reactions has been compared with uncatalyzed reactions and found that the catalyzed reactions are 9-11 folds faster. The catalytic constants (KC) have been calculated for each N-haloamine at different temperatures and the values of activation parameters with respect to the catalyst have been evaluated. Spectroscopic evidence for the formation of 1:1 complex between N-haloamine and ruthenium has been obtained. The observed results have been explained by a plausible mechanism and the related rate law has been deduced.
Effect of substituent in diazotized orthanilic acid on the azo coupling with 7-acetylamino-4-hydroxynaphthalene-2-sulfonic acid in citrate-phosphate buffers
Kornev,Zheltov
, p. 1095 - 1099 (2007/10/03)
Effect of substituent in the para position with respect to the diazo group in diazotized orthanilic acid derivatives on the rate and selectivity of azo coupling with 7-acetylamino-4-hydroxynaphthalene-2-sulfonic acid was studied in citrate-phosphate buffers. The selectivity of azo coupling at the 3-position of the azo component almost does not depend on the nature of electron-donor substituent. Electron-acceptor groups considerably reduce the selectivity of formation of the 3-isomer. Previous conclusions, according to which the rate-determining stages are different depending on the site of azo coupling of diazotized orthanilic acid with 7-acetylamino-4-hydroxynaphthalene-2-sulfonic acid, were found to be also valid for some 5-substituted orthanilic acid derivatives. The rate-determining stage in the azo coupling at the 3-position can change upon introduction of strong electron-acceptor substituents capable of interacting with the diazo group. The contribution of the multicenter mechanism of deprotonation of the σ-complex with participation of water molecules was presumed to increase in going to the diazo components having electron-donor substituents.
Alkanol substituted disazo orange dye for nylon
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, (2008/06/13)
The specification describes a new group of alkanol substituted disazo compounds that are useful in dyeing polyamide textile fibers in orange hues. The new compounds are compatible with several acid blue dyes and several acid red dyes that are commercially important as dyes for nylon. The new compounds are particularly well suited for use as the "yellow" component in trichromatic systems for dying polyamide carpeting and other textiles. The new compounds are relatively inexpensive to make and have outstanding application and fastness properties. Other aspects of the specification are concerned with a method of making the new compounds and with a method of dyeing polyamides with said compounds and to the novel dyed polyamides resulting from the use of the new group of compounds as dyes.
