- Development of an efficient ruthenium catalyzed synthetic process and mechanism for the facile conversion of benzothiazoles to orthanilic acids
-
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.
- 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)
-
- Preparation, crystal structure and microwave studies on ring-substituted arylammonium hydrogen sulfate salts
-
Three ring substituted arylammonium hydrogen sulfates (RSAHS)/ring substituted dianilinium sulfates (RDAS) have been prepared from corresponding arylamines by treatment with excess conc. H2SO4 and characterized by X-ray crystallography, elemental, gravimetric and spectral analyses. The RSAHS/RDAS salts yield the corresponding ring substituted amino benzene sulfonic acids (RSABSA) when subjected to microwave irradiation. It is observed that these salts undergo transformation to acid in solid state via proton transfer reaction prior to sulfonation.
- Kapoor,Srivastava, Pratibha,Singh, Gurdip,Froehlich, Roland
-
p. 1283 - 1288
(2008/09/18)
-
- Triazinyl reactive dyes containing additional fiber reactive groups bound through the sulfonylalkylaminoalkylamino bridge
-
The invention relates to novel useful reactive dyes of the formula I STR1 in which: F is a radical selected from the group consisting of metal-free or metal-containing monoazo or disazo dyes containing at least one --SO3 H group, anthraquinone dyes, sulfophthalocyanine dyes, formazan dyes, phenazine dyes, oxanine dyes and nitroaryl dyes, R is hydrogen, C1 -C4 alkyl which is unsubstituted or substituted with --COOH or --SO3 H, cyanoethyl, or hydroxyethyl, X is fluorine, chlorine, bromine, --SO3 H, phenylsulfonyl or C1 -C4 -alkylsulfonyl, P is 1 or 2 and A is a radical of the formula STR2 in which: the groups designated "alk" are independently of each other straight or branched polymethylene radicals having 2 to 6 carbon atoms, and Z is β-halogenoethyl, vinyl, β-sulfatoethyl, β-thiosulfatoethyl or βacetoxyethyl.
- -
-
-
- Reactive dyestuffs comprising a triazine moiety and a vinylsulfonyl moiety both being linked by a substituted alkylene bridge member
-
A reactive dye of the formula STR1 in which: F is a radical selected from the group consisting of metal-free or metal-containing monoazo or disazo dyes containing at least one --SO3 H group, anthraquinone dyes, sulfophthalocyanine dyes, formazan dyes, phenazine dyes, oxazine dyes and nitroaryl dyes, R is hydrogen, C1 -C4 alkyl which is unsubstituted or substituted with --COOH or --SO3 H, cyanoethyl, or hydroxyethyl, X is fluorine, chlorine, bromine, --SO3 H, phenylsulfonyl or C1 -C4 -alkylsulfonyl, p is 1 or 2 and A is a radical of the formula STR2 in which: Y is chlorine, bromine, fluorine, --OH, --OSO3 H, --O-acyl, --CN, --COOH, --COO--C1 -C4 -alkyl, --CONH2 or --SO2 --Z, the group designated "alk" is a straight or branched polymethylene radical having 2 to 6 carbon atoms, V is STR3 hydrogen or C1 -C4 -alkyl which is unsubstituted or substituted by C1 -C2 -alkoxy, carboxyl, sulfo, halogen or hydroxy, Z is β-halogenoethyl, vinyl or β-acetoxyethyl, or A is a radical of the formulae STR4 in all of which R' is C1-6 -alkyl or hydrogen, Z is as defined above, o is 0 to 6, and m is 2 to 6.
- -
-
-
- Bisazo brown reactive dye
-
A brown reactive dye represented by a free acid of the formula, STR1 wherein R is a hydrogen atom or a C1 to C4 alkyl group, X is --SO2 CH2 CH2 Cl, --SO2 CH=CH2, --SO2 CH2 CH2 OSO3 H or --SO2 CH2 CH2 OPO3 H2, rings A, B and C are each a benzene or naphthalene ring which may have other substituent, m is 0 to 3 and n is 0 to 1. This dye is suitable for dyeing cellulose fibers brown to afford dyeings superior in fastnesses, acid stability, build-up property and level dyeing property.
- -
-
-
- Process for the preparation of 1-aminobenzene-2-sulphonic acids
-
Process for the preparation of 1-aminobenzene-2-sulphonic acids of the formula STR1 wherein R=H or a substituent and n=1-4, and their salts, in particular their alkali metal salts, by oxidation of compounds of the formula STR2 wherein R1 =H, a cation, in particular an alkali metal cation, or a radical of the formula STR3 characterized in that the oxidation is carried out in a weakly acidic to alkaline pH range. The process can also be carried out as a one-pot process, using the corresponding benzothiazoles as starting materials.
- -
-
-
- Dis-, tris-, and tetrakisazo compounds containing resorcinol, sulfonylamino, and two or three sulfonic acid groups
-
The present invention discloses substituted phenyl di and trisazo dyes free of reactive groups having two or three sulfonic acid groups, of the general formula: STR1 wherein D1 is STR2 Z is hydrogen or D4 --N=N--; D2 is phenyl substituted by hydroxyl, hydroxysulfonyl, chlorine or nitro, or is naphthyl substituted by hydroxy, hydroxysulfonyl or nitro, X, independently of one another, are hydroxyl or amino, D3 is phenyl which is substituted by hydroxysulfonyl, chlorine, bromine, methyl, methoxy, ethoxy, nitro, phenylamino, sulfophenylamino or nitrosulfophenylamino, or is naphthyl which is substituted by hydroxysulfonyl; D4 is phenyl which is unsubstituted or substituted by methyl, ethyl, methoxy, ethoxy, chlorine, bromine, nitro, sulfamoyl or hydroxysulfonyl, or is naphthyl which is substituted by hydroxysulfonyl; and R2 is methyl, ethyl or allyl; the rings B and E may additionally be substituted by methyl, ethyl, methoxy, ethoxy, chlorine, bromine or hydroxysulfonyl, with the proviso that D2 has a hydroxyl group ortho to the azo bond; or the iron, manganese, cobalt, chromium, nickel or copper complexes of this dye. These compounds, particularly in the form of their metal complexes are suitable for dyeing nitrogen-containing fibers such as wool, and preferably, leather. The present dyes yield very fast brown hues, in particular on retanned leather.
- -
-
-
- Azo dyestuffs
-
Azo dyestuffs, which in the acid form, are represented by the formula: wherein A is an aromatic radical, M is a 1,4-benzene radical which may be substituted, E is the residue of a coupling component which is free from azo groups, At least one of A and M containing a phosphonic acid group, and the metal complexes of those having a metallisable group are reactive dyes suitable for use in the process of German OLS No. 2324809.
- -
-
-