Estimations dimethylaniline

Then there are a number of pesticides, e.g. the phenolic herbicide dinoseb and the fungicide pentachlorophenol, whose speciation varies strongly in the environmental pH-range. For this reason, one has to consider the pwhen estimating their environmental fate. Structures of the compounds discussed in this section are depicted in Table 1, together with a listing of their pand octanol-water partition coefficients, Kow, of the neutral species (unless otherwise indicated). Typical basic pollutants include the industrial chemicals aniline and jV.jV-dimethylaniline. 

The strongly electrophilic pyrylium perchlorate 160a was readily reduced with cyclooctatriene,213 toluene, anisole, dimethylaniline,214 or diphenyl-methanol215 to 2,6-bis(methoxycarbonyl)-4//-pyran (161a). Other perchlorates like 160 exhibit similar behavior toward alcohols equilibrium constants for the redox processes were estimated.216... 

Examjdes.—Aniline is rapidly tribrominated at room temperature, the end point is very sharp, and this estimation of aniline is preferable to the nitrous acid method. At ordinary temperature ortho- and para-toluidines are dibrominated and meta-toluidine is tribrominated. Dimethylaniline is monobrominated at 0°—5°, dibrominated at 40°—50° and tribrominated at 60°—70°, an interesting example of the effect of temperature. Sulphanilic acid at 60°—70° yields tribromoaniline, and at this temperature p-nitroaniline reacts quantitatively. Phenol at about 22° yields tribromophenol. For reference to the estimation of m-diamines, m-dihydroxy compounds, R salt, cresols, p nitroaniline, diphenylamine, p-nitrophenol, and other notes, see J. S. C. I., 41, 161. 

Novel techniques for the study of fast reactions were employed to study the bromination of AT.AT-dimethylaniline and its derivatives by Bell and Ramsden (1958). The second-order rate constant for the bromination of N,AT-dimethylaniline in acid solution was approximately 109 1. mole-1 sec-1. An estimate of the rate of bromination relative to the rate of substitution of benzene indicates that the methylated aniline is 1019 times more reactive (Robertson et al., 1953). The large influence of the p-dimethylamino substituent has discouraged extended quantitative study. Nevertheless, Eabom and his associates (Eabom, 1956 Eaborn and Pande, 1961a Eabom and Waters, 1960) assessed the influence of the group in several displacement reactions. Eaborn points out, however, that the resulting partial rate factors are only approximate. 

A wet sample (0.01 - 0.1 g) is added to the digestion flask and 4 ml of mixed reagent are added. The gas flow is started and the sample is refluxed for an hour. Potassium sulfate is used for a standard. The hydrogen sulfide produced is estimated by the p-amino dimethylaniline-ferric ammonium sulfate spectrophotometric method [76] utilising the 670 nm absorption maximum. Reagent blanks are run. Reagent blanks are low (< 0.03 xM s). 

S04 ) and we have estimated its one-electron reduction potential to be about 1.1V at pH 7. Of particular interest is the ability of S05 to oxidize certain substances (aniline and dimethylaniline, for example) which form radicals which are capable of oxidizing sulfite. This can lead to the enhancement of the autoxidation of sulfite through the chain... 

Surface water estimated t,/2 = 2.0 d for dimethylaniline in Rhine River in case of a first order reduction process (Zoeteman et al. 1980)... 

The presence of aniline is shown by the carbylamine reaction. Aniline and monomethylaniline react with acetic anhydride. An approximate estimate can be obtained by the rise of temperature when 50 c.c. of the dlmethylaniline and 10 c.c. of acetic anhydride are brought together in a Dewar vessel. A comparative experiment should be made with dimethylaniline containing a known amount of monomethylaniline. Alternatively the amount of acetic anhydride used up may be determined by filtration. A weighed quantity of acetic anhydride (about 2 5 g.) is added to a weighed quantity of dimethyl-aniline (about 10 g.). The acetylation is allowed to proceed for two to three hours, 70 c.c. of water added and the whole warmed on a water-bath for half an hour and then titrated with sodium hydroxide. This gives the quantity of acetic anhydride not used in acetylation. 

Macdonald, T.L. Gutheim, W.G. Martin, R.B. and Guengerich, F.P. Oxidation of substituted N,N-dimethylanilines by cMochrome P-450 Estimation of the effective oxidation-reduction potential of cytochrome P-450. Biochemistry 2% 5) 2i)l -2Qll, 1989. 

N. N-dimethylanilines by cytoehrome P-450 Estimation of the effective oxidation-reduetion potential of cytochrome P-450. Biochemistry 28, 2071-2077. 

Macdonald, T.L., W.G. Gutheim, R.B. Martin, and F.P. Guengerich (1989). Oxidation of substituted iV,/V-dimethylanilines by cytochrome P450 Estimation of the effective oxidation-reduction... 

Macdonald TL, Gutheim WG, Martin RB, Guengerich FP. Oxidation of substituted A,A-dimethylanilines by cytochrome P450 estimation of the effective oxidation-reduction potential of cytochrome P450. Biochemistry 1989 28 2071-2077. 

Steric resonance inhibition has been ascotained for iV-methyl- and NJ -dimethylanilines with further substituents in the ortho positions By considering the changes in the first three orbital levels as observed by PE spectroscopy, the amount by which the nitrogen lone-pair electrons are twisted about the N-phenyl bond can be estimated. For example, the dihedral angle of A,A-dimethyl-2,6-dimethylaniline (2) was estimated at 30-46° from the lone-pair ionization energy as well as from the split of 7T2 and T3. These classical investigations by Maier and Turner in the field of conformational analysis by PE spectroscopy have been reviewed previously . ... 

The peroxymonosulfate radical is a stronger one-electron oxidant than the sulfite radical and has been shown to react with a number of reductants more rapidly than does 803" (Table 3). Indeed this radical can oxidize some substances (for example, aniline and dimethylaniline) leading to radicals which can, in turn, oxidize sulfite ions. In these cases, the reduction potential of the substrate is intermediate between those of 803" and 805" (for aniline, = 1.03 V and for dimethylaniline, =0.86 V [109]). 8ome early kinetic results suggested that the one-electron reduction potential for 8O5 was about 1.1 V [ 110], while a calculation based on an estimated homolysis energy led to an estimate of 1.7 V... 

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