Acidity continued phenols

Weak cation exchanger—macroreticular type—carboxylic acid or phenolic functionality continued) ... 

Figure 1.7 shows both the experimental and predicted values (continuous line) of both the ICE and COD evolution with the specific electrical charge passed during the anodic oxidation of different classes of organic compounds (acetic acid, isopropanol, phenol, 4-chlorophenol, 2-naphtol). This figure demonstrates that the... 

Experiments were performed in batch reactors at 21 1°C with a continuous stirring at 300 rpm and some ratio solid/solution fixed at 2.26 g.L for dry pulp and 0.3 g.L for activated carbon. A pre-hydration of 90 min of the pulp was necessary and the pH of the solution was stabilized at 5.5. Equilibrium times were deduced from the kinetics. The mixed metallic solutions had equimolar initial concentrations (8.10 mol.L ). The influence of benzaldehyde, benzoic acid and phenol on the fixation of Cu onto the pulp was conducted using 100 mg.L (expressed in TOC) of organic compounds. The adsorption on the mixture of sorbents of phenol and Cu ions was carried out with 50 mg.L of each components. 

Rate constants, have been evaluated for proton transfer from a variety of acids, HA, to diazoacetate ion. For a series of neutral oxygen acids including both carboxylic acids and phenols, logAry is a continuous but nonlinear function of log after both are corrected for small symmetry factors. This function can be... 

In the technical literature, this approach was considered, in only a few studies. For instance, Ag, Au, Cd, Cr, Hg, Ni and Pt dissolved as metal cations in water media were successfully photoreduced in the presence of methanol, formic acid, salicylic acid, EDTA, phenol and nitrobenzenes (Burns et al., 1999 Prairie et al., 1993). Furthermore, the reduction of these inorganic species can be enhanced in the presence of the described organic molecules (hole scavengers) (Buttler and Davis, 1993 Chen and Ray, 2001 R airie et al., 1993). Thus, there is evidence of the importance of the combined organic and inorganic pollutant photoconversion and this topic deserves continued attention in order to take full advantage of enhancement effects. 

This confirms the findings of Devraine (1969), who also conclnded that large nuclei stop growing as they release fines , i.e. daughter nuclei. This observation explains the continued effectiveness in stabilizing white wines of cream of tartar that has been recycled five times, provided that the particles were initially very small. On the other hand, it is not possible to recycle cream of tartar so many times in red wines dne to the affinity between tartaric acid and phenols, known to be powerful crystallization inhibitors. 

Intense interest has continued in the uses of various chelates of fiuorinated diketones as n.m.r. shift reagents, which have been reviewed in monograph form. Papers of note have been published on (i) self-association and adduct formation of the chelates of l,l,l,2,2,3,3-h tafluoro-7,7-dimethyloctane-4,6-dione M(fod)3 (78 M = Pr or Eu) (ii) the use of Eu(fod)s as a shift reagent for carboxylic acids and phenols (an earlier report ii claimed that it was unsuitable) (iii) application... 

SO -HgOg added dropwise with stirring to a soln. of S-2,6-diisopropylphenyl di-methylthiocarbamate in formic acid, stirring continued overnight, and the product isolated as the Na-salt -> Na-2,6-diisopropylbenzenesulfonate. Y 57.7%. - In combination with Synth. Meth. 22, 625 this reaction constitutes a method for the prepn. of ar. sulfonic acids from phenols. F. e. s. J. E. Cooper and J. M. Paul, J. Org. Chem. 35, 2046 (1970). 

The urine was adjusted to pH 4.6 with acetate buffer and incubated with p-glucuronidase-arylsufa-tase (3 mL/100 mL of fresh urine) at 37°C for 48 h, followed by continuous ether extraction for 48 h. The ether extracts were washed with 5% NaHCOj and 5% NaOH to remove the acidic and phenolic components, respectively. The ether extract was dried over MgS04, followed by evaporation of the solvent to give the neutral crude metabolites (Ishida et al., 1981). 

There are numerous examples of purified materials by the above-mentioned two types of suspension crystallization process designs some of them are acetic acid, caprolactam, methacrylic acid, and phenol. The two discussed suspension crystallization concepts, shown in the Figures 17.9 and 17.10, count to the continuous packed column with mechanical forced transport. 

Extraction has to be continued until all lichen substances are dissolved (6-60 h). Often heavily soluble compounds precipitate in the extract and can be removed by filtration. One way to work up the extract is separation in an acid, a phenolic and a neutral part, by shaking successively with a solution of NaHCOj (10% in H2O) and NaOH (2% in HjO). Some compounds, e.g. chlorinated phenolics, are soluble in a solution of Na2C03 (5% in H2O). Shaking should be continued for 10-15 min. Another way is chromatography of the extract over silica gel. The ratio of product to adsorbent is about 1 30 to 1 50, and an approved sequence of eluents is n-hex-ane-diethyl ether-methanol. Many extracts are heavily soluble in n-hexane to overcome this difficulty, the mixture is dissolved in a proper... 

Acidic Component. The filtrate from (a) or the first alkali extract from (h) will contain the acidic component, which will be either an acid or a phenol. Continue as follows ... 

The controlled thermal decomposition of dry aromatic diazonium fluoborates to yield an aromatic fluoride, boron trifluoride and nitrogen is known as the Schiemann reaction. Most diazonium fluoborates have definite decomposition temperatures and the rates of decomposition, with few exceptions, are easily controlled. Another procedure for preparing the diazonium fluoborate is to diazotise in the presence of the fluoborate ion. Fluoboric acid may be the only acid present, thus acting as acid and source of fluoborate ion. The insoluble fluoborate separates as it is formed side reactions, such as phenol formation and coupling, are held at a minimum temperature control is not usually critical and the temperature may rise to about 20° without ill effect efficient stirring is, however, necessary since a continuously thickening precipitate is formed as the reaction proceeds. The modified procedure is illustrated by the preparation of -fluoroanisole ... 

Cautiously add 250 g. (136 ml.) of concentrated sulphuric acid in a thin stream and with stirring to 400 ml. of water contained in a 1 litre bolt-head or three-necked flask, and then dissolve 150 g. of sodium nitrate in the diluted acid. Cool in a bath of ice or iced water. Melt 94 g. of phenol with 20 ml. of water, and add this from a separatory funnel to the stirred mixture in the flask at such a rate that the temperature does not rise above 20°. Continue the stirring for a further 2 hours after all the phenol has been added. Pour oflF the mother liquid from the resinous mixture of nitro compounds. Melt the residue with 500 ml. of water, shake and allow the contents of the flask to settle. Pour oflF the wash liquor and repeat the washing at least two or three times to ensure the complete removal of any residual acid. Steam distil the mixture (Fig. II, 40, 1 or Fig. II, 41, 1) until no more o-nitrophenol passes over if the latter tends to solidify in the condenser, turn oflF the cooling water temporarily. Collect the distillate in cold water, filter at the pump, and drain thoroughly. Dry upon filter paper in the air. The yield of o-nitrophenol, m.p. 46° (1), is 50 g. 

P-Hydroxy-a-naphthaldehyde, Equip a 1 litre three-necked flask with a separatory funnel, a mercury-sealed mechanical stirrer, and a long (double surface) reflux condenser. Place 50 g. of p-naphthol and 150 ml. of rectified spirit in the flask, start the stirrer, and rapidly add a solution of 100 g. of sodium hydroxide in 210 ml. of water. Heat the resulting solution to 70-80° on a water bath, and place 62 g. (42 ml.) of pure chloroform in the separatory funnel. Introduce the chloroform dropwise until reaction commences (indicated by the formation of a deep blue colour), remove the water bath, and continue the addition of the chloroform at such a rate that the mixture refluxes gently (about 1 5 hours). The sodium salt of the phenolic aldehyde separates near the end of the addition. Continue the stirring for a further 1 hour. Distil off the excess of chloroform and alcohol on a water bath use the apparatus shown in Fig. II, 41, 1, but retain the stirrer in the central aperture. Treat the residue, with stirring, dropwise with concentrated hydrochloric acid until... 

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