Of 2,4-dinitrophenol

Amino-4-nitropheno1 is produced commercially by the partial reduction of 2,4-dinitrophenol This reduction may be achieved electrolyticaHy using vanadium (159) or chemically with polysulftde, sodium hydrosulftde, or hydrazine and copper (160). Alternatively, 2-acetamidophenol or 2-methylbenzoxazole may be nitrated in sulfuric acid to yield a mixture of 4- and 5-nitro derivatives that are then separated and hydrolyzed with sodium hydroxide (161). 

Another example of the analogy between pyrazole and chlorine is provided by the alkaline cleavage of l-(2,4-dinitrophenyl)pyrazoles. As occurs with l-chloro-2,4-dinitrobenzene, the phenyl substituent bond is broken with concomitant formation of 2,4-dinitrophenol and chlorine or pyrazole anions, respectively (66AHC(6)347). Heterocyclization of iV-arylpyrazoles involving a nitrene has already been discussed (Section 4.04.2.1.8(i)). Another example, related to the Pschorr reaction, is the photochemical cyclization of (515) to (516) (80CJC1880). An unusual transfer of chlorine to the side-chain of a pyrazole derivative was observed when the amine (517 X = H, Y = NH2) was diazotized in hydrochloric acid and subsequently treated with copper powder (72TL3637). The product (517 X = Cl, Y = H) was isolated. 

A kinetic method for the determination of 2,4-dinitrophenol is proposed. The method is based on the inhibiting effect of 2,4-dinib ophenol on the Mn(II) catalysis of the oxidation of malachite green with potassium periodate. The reaction was followed spectrophotometrically at 615 nm. The optimal experimental conditions for the determination of 2,4-dinitrophenol were established under the optimal reaction conditions ... 

A linear dependence was established between tga and the concenb ation of 2,4-dinitrophenol ... 

The method was applied for the determination of 2,4-dinitrophenol in urine. The reproducibility was very good. The results obtained by the proposed method also agreed well with the values obtained by standard methods. 

Commercial Dinitrophenol consists almost entirely of 2,4-Dinitrophenol, and its properties are identical with those given above... 

Salts of 2,4-Dinitrophenol. 2,4-DNPh forms numerous metallic salts, most of which are expl, eg ... 

Fig. 1 Reflectance scan of a chromatogram track with 30 ng each of 2,4-dinitrophenol (1) and 2,6-dinitrophenol (2), 60 ng each of 2,5-dinitrophenol (3), 4-nitrophenol (4) and 120 ng each of 3-nitrophenol (5) and 2-nitrophenol (6) per chromatogram zone.

Blasco R, E Moore, V Wray, D Pieper, K Timmis, F Castillo (1999) 3-Nitroadipoate, a metabolic intermediate for mineralization of 2,4-dinitrophenol by a new strain of a. Rhodococcus species. J Bacterial 181 149-152. 

Lenke H, DH Pieper, C Bruhn, H-J Knackmuss (1992) Degradation of 2,4-dinitrophenol by two Rhodococcus erythropolis strains, HL 24-1 and HL 24-2. Appl Environ Microbiol 58 2928-2932. 

The editor would be surprised if it proved impossible to detonate this analytical reagent, the carboxylation product of 2,4-dinitrophenol, especially in contact with bases. There is no record of problems in use. 

Cl Sulphur Black 1, which is produced from the relatively simple intermediate 2,4-dinitrophenol and aqueous sodium polysulphide. A similar product (Cl Sulphur Black 2) is obtained from a mixture of 2,4-dinitrophenol and either picric acid (6.148 X = N02) or picramic acid (6.148 X = NH2). A black dye possessing superior fastness to chlorine when on the fibre (Cl Sulphur Black 11) can be made from the naphthalene intermediate 6.149 by heating it in a solution of sodium polysulphide in butanol. An equivalent reaction using the carbazole intermediate 6.150 gives rise to the reddish blue Cl Vat Blue 43 (Hydron blue). This important compound, which also possesses superior fastness properties, is classified as a sulphurised vat dye because it is normally applied from an alkaline sodium dithionite bath. Interestingly, inclusion of copper(II) sulphate in the sulphurisation of intermediate 6.150 leads to the formation of the bluish black Cl Sulphur Black 4. 

Kelly DP, Syrett PJ. 1963. Effect of 2 4-dinitrophenol on carbon dioxide fixation by a Thiobacillus. Nature 197 1087-9. 

Dabkowski et al [28] have found that 2,4-dinitrophenol (DNP), whose pKa=4.1 is close to that of tetrazole pKa 4.9, acts as an efficient activator of phosphate synthesis via the phosphoroamidite procedure. The reaction of amidites with an equivalent amount of nucleoside in the presence of 2,4-dinitrophenol proceeds in very high yield and at rates comparable or higher than those when tetrazole is used. Phosphitylations activated by 2,4-dinitrophenol (DNP) take place at room temperature in aprotic solvents like THE,... 

Phenol ethers, like the parent phenols, are reactive substrates. Phenol ethers like anisole and phenetole are readily nitrated to their picryl ethers, 2,4,6-trinitroanisole and 2,4,6-trinitrophenetole respectively, on treatment with mixed acid composed of concentrated nitric and sulfuric acids at 0 °C. Such reactions are vigorous, prone to oxidative side-reactions, and pose a considerable safety risk. The direct nitration of 2,4-dinitrophenol ethers, obtained from the reaction of 2,4-dinitrochlorobenzene with alkoxides, provides a more practical route to picryl ethers on an industrial scale. ... 

Very little information is available about the nature of urinary metabolites of 1,3-DNB in humans. In a study that evaluated 1,3-DNB urinary metabolites after a single dermal exposure, amino and nitro metabolites were grouped together and reported as a single value relative to the level of 2,4-dinitrophenol as a standard (Ishihara et al. 1976). Amino and nitro metabolites may be derived from a variety of nitroaromatic compounds thus, they are not specific for 1,3-DNB. 

Moreover, uncoupHng experiments using Escherichia coli cells were described. An addition of glucose to stationary E. coli cells leads to an increase of fluorescence intensity in the region of NAD(P)H, because it is formed in the glycolysis. This increase was stopped abruptly by addition of 2,4 dinitrophenol (DNP), which effects a decrease in the fluorescence signal according to the theory of uncoupled oxidative phosphorylation. The dynamics of this process. 

Morley GE, Anumonwo JMB, Delmar M Effects of 2,4-dinitrophenol or low [ATP on cell excitability and action potential propagation in guinea pig ventricular myocytes. Circ Res 1992 71 821-830. 

Illustrative Example 25.5 Continuing the Case of 2,4-Dinitrophenol in River R... 

In Illustrative Example 25.5 we continue our discussion on the infiltration of 2,4-dinitrophenol into an aquifer. 

In River R a pollution cloud of 2,4-dinitrophenol (see Illustrative Example 25.2) of duration At = 1 h and concentration Cin =50 ng L-1 is passing by Groundwater System S. Calculate the maximum concentration reached at the wells for the three regimes. Compare these values to the maximum concentrations reached 3 m away from the river. 

Continuous measurements of 2,4-dinitrophenol in River R (see Illustrative Examples 25.1 to 25.4) passing by the GWS show a superposition of sinusoidal diurnal and annual concentration variations (Eq. 25-33). Calculate how much of this variation is observed at one of the wells and determine the phase shift (in days) between the oscillations in the river and in the well. Include into the analysis also a monthly oscillation (t = 30 days). Make all calculations for the three flow regimes. 

One day, measurements in the river suddenly show rather high concentrations of 2,4-dinitrophenol. Further observations show that the values vary on a weekly basis and reach maximum concentrations Cmax = 3.5 pg L during the week and minimum concentrations Cmin = 1.3 pg L"1 over the weekend. Calculate the maximum concentration of 2,4-dinitrophenol to be expected at the drinking-water well. The pH in die infiltrating water is 7.8. 

Whistles, Pyrotechnic. US projectile ground-burst and booby-trap flash simulators precede their flash and expin with a whistling sound. The fact that certain compns whistle when compressed into a tube and ignited has been used in the fireworks industry for many years. The active substance most often used in pyrot whistles is gallic acid (3,4,5-trihydroxybenzoic acid). The K salts of benzoic acid of 2,4-dinitrophenol and of picric acid (2,4,6-trinitrophenol) and the Na salt of salicylic acid (o-hydroxybenzoic acid) are also effective. They are combined with K chlorate,... 

Knowledge of the enzymes used by microorganisms in the transformation of nitroaromatic compounds is limited. Blasco Castillo (1993) characterized an inducible nitrophenol reductase from Rhodobacter capsulatus that catalyzed the reduction of 2,4-dinitrophenol (DNP) to 2-amino-4-nitrophenol. This enzyme was a dimer that contained flavin mononucleotide and possibly nonheme iron as... 

Amino-4-nitrophenol has been prepared by the partial reduction of 2,4-dinitrophenol chemically -6 and electrolytically,6 and by the action of sulfuric add on 3-nitroazidobenzene.7... 

Much of the development in this field is traceable to two quite different original interests. The first goes back to Ullmann and Nddai s observation27 that the p-toluenesulfonate of 2,4-dinitrophenol, like 2,4-dinitrochlorobenzene, reacts with amines these cause desulfonyloxyla-tion. For example, with aniline, the following reaction occurred ... 

Cognate preparation. Reduction of 2,4-dinitrophenol. It is an interesting student exercise to carry out the reduction of 2,4-dinitrophenol under the conditions described above for m-dinitrobenzene. The spectroscopic features of the isolated and purified product, together with the melting point, in comparison with the literature values for the possible isomers, should enable a deduction to be made on the regioselectivity of the reaction. 

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