- Halogenation of enol tautomers of 2-cyanoacetamide and malonamic acid
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Reactions of 2-cyanoacetamide (CA) with both bromine and iodine at low halogen concentration in aqueous acid solution were first order in halogen and CA, consistent with an interpretation involving rate-limiting halogenation of the enol tautomer. There was no acid dependence in the range 0.1-0.5 mol dm-3. The observed rate constants for bromination and iodination were very similar, indicating that both probably occurred at the encounter limit. This enabled a value for KE, the equilibrium constant for enolisation, to be determined as 6 × 10-10. There was strong evidence that at low acidities (pH ～ 4) enolisation is rate-limiting, but we were unable to achieve a fully zero-order kinetic dependence upon halogen. However we did obtain a value for the acid-catalysed enolisation rate constant ke of 2.7 × 10-3 dm3 mol-1 s-1 from measurements of rates of deuterium exchange with the solvent. The bromination of malonamic acid (ML) in dilute acid solution at low [Br2] was zero-order in [Br2] and we obtained a value of 1.3 × 10-2 dm3 mol-1 s-1 for the acid catalysed enolisation rate constant. There is some evidence which suggests that enolisation of ML takes place via the amide group rather than the carboxylic acid group. The results are compared with earlier studies.
- Eberlin, Alex,Williams, D. Lyn H.
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- Synergistic biocide composition
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A biocide composition is provided as an addition to substances that can be infected by harmful microorganisms, in which the biocide composition has at least two active biocidal substances, one of which is 2-methylisothiazolin-3-one. The composition is characterized in that it contains 1,2-benzisothiazolin-3-one, compositions containing 5-chloro-2-methylisothiazolin-3-one being excluded. In comparison with its individual components, the composition of the invention has a synergistic biocidal activity.
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- Aqueous isothiazolone formulation
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An aqueous isothiazolone formulation useful for antiseptic or antifungal treatment of various synthetic polymeric emulsions, which comprises (a) a specific isothiazolone compound, (b) water or an aqueous solvent and (c) a specific nitrobromo or cyanobromo compound.
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- Synergistic antialgal compositions comprising diphenylethers and certain commercial biocides, methods of controlling algae, and coating compositions comprising the antialgal compositions
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Synergistic antialgal compositions comprising substituted fluoroalkyl diphenylethers and a material selected from the group consisting of sodium hypochlorite, halodialkylhydantoin, n-alkyl dimethyl benzylammonium chloride, 2,2-dibromo-3-nitrilopropionamide, 2-bromo-2-nitro-1,3-propanediol, poly[oxyethylene(dimethylimino)ethylene(dimethylimino)ethylene dichloride], 3-iodo-2-propynylbutylcarbamate, sodium N-methyldithiocarbamate, 3-(3,4-dichlorophenyl)-1,1-dimethylurea, N-(phosphonomethyl)glycine and salts thereof, zinc bis(dimethyldithiocarbamate), p-tolyldiiodomethylsulfone and fatty acid salt in ratios to each other which exhibit synergism are disclosed. Particularly effective combinations are based on oxyfluorfen as the diphenylether for use in protecting aqueous systems, such as latices and cooling water systems, from algal growth.
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