Intensity phenol

DCMX which is obtained by reaction of 4-chloro-3,5-dimethylphenol (PCMX 7.3.2.) with N-chloroaceta-mide in glacial acetic acid plus concentrated HCl behaves similar to PCMX in activity and properties, but is of inferior importance in application as an active agent in pine oil based disinfectants or as a preservative for functional fluids, as it is even less soluble in water than PCMX and has a more intense phenolic smell. 

For the production of black unfermented olives, the ripe fruit is placed 3-5 times in 1-2% NaOH. In between the fruit is washed and well aired to ensure that the flesh is uniformly dyed black by intensive phenol oxidation. Iron gluconate is added to the last wash water to stabilize the color. The olives are then packed in a 3% NaCl solution and sterilized. The product has a pH value of 5.8-7.9 and contains 1-3% of common salt. 

The difference between the aroma of the beverage and that of ground coffee is the more intensive phenolic, buttery, caramel-like note and a we iker roasty note. These changes are caused by shifts in the concentrations of the aroma substances during brewing (Table 21.8). Compounds hke 2,3-butandione, the furanones 6, 7 and 27, 2-ethyl-3,5-pyrazine, the thiols 17 and 18 are extracted with yields of >75%, while only 25% or less of 2-ethenyl-3-ethyl-5-methylpyrazine, 3-iso-butyl-2-methoxypyrazine, 2-furfurylthiol and P-damascenone pass into the beverage. The low yield of 2-furfurylthiol is partly due to reactions which occur during percolation of the coffee powder. 

The most important reaction of the diazonium salts is the condensation with phenols or aromatic amines to form the intensely coloured azo compounds. The phenol or amine is called the secondary component, and the process of coupling with a diazonium salt is the basis of manufacture of all the azo dyestuffs. The entering azo group goes into the p-position of the benzene ring if this is free, otherwise it takes up the o-position, e.g. diazotized aniline coupled with phenol gives benzeneazophenol. When only half a molecular proportion of nitrous acid is used in the diazotization of an aromatic amine a diazo-amino compound is formed. 

Fluorescein reaction. Repeat Test i, using however resorcinol instead of phenol. A reddish solution having an intense green fluorescence is produced. 

Dissolve 1 g. of the secondary amine in 3-5 ml. of dilute hydrochloric acid or of alcohol (in the latter case, add 1 ml. of concentrated hydrochloric acid). Cool to about 5° and add 4-5 ml. of 10 per cent, sodium nitrite solution, and allow to stand for 5 minutes. Add 10 ml. of water, transfer to a small separatory funnel and extract the oil with about 20 ml. of ether. Wash the ethereal extract successively with water, dilute sodium hydroxide solution and water. Remove the ether on a previously warmed water bath no flames should be present in the vicinity. Apply Liebermann s nitroso reaction to the residual oil or solid thus. Place 1 drop or 0 01-0 02 g. of the nitroso compovmd in a dry test-tube, add 0 05 g. of phenol and warm together for 20 seconds cool, and add 1 ml. of concentrated sulphuric acid. An intense green (or greenish-blue) colouration will be developed, which changes to pale red upon pouring into 30-50 ml. of cold water the colour becomes deep blue or green upon adding excess of sodium hydroxide solution. 

Phenol condenses with phthahc anhydride in the presence of concentrated sulphuric acid or anhydrous zinc chloride to yield the colourless phenolphthalein as the main product. When dilute caustic alkah is added to an alcoholic solution of phenolphthalein, an intense red colouration is produced. The alkali opens the lactone ring in phenolphthalein and forms a salt at one phenolic group. The reaction may be represented in steps, with the formation of a h3q)othetical unstable Intermediate that changes to a coloured ion. The colour is probably due to resonance which places the negative charge on either of the two equivalent oxygen atoms. With excess of concentrated caustic alkali, the first red colour disappears this is due to the production of the carbinol and attendant salt formation, rendering resonance impossible. The various reactions may be represented as follows ... 

When making vanillin from guaiacol the chemist can smell success because the product will have an intense vanilla odor. One can even flavor cookies with the stuff (true ). This Riemer-Tiemann method is also an excellent way to get salicylal-dehyde from phenol in yields of up to 50%. The chemist does everything the same except uses NaOH instead of KOH. 

Mass Spectrometry A peak for the molecular ion is usually quite prominent m the mass spectra of phenols It is for example the most intense peak m phenol... 

The intense reddish-brown color of the acetylacetone titanium complexes impart a yellow discoloration to white inks. This discoloration is accentuated when the inks are used to print substrates that contain phenol-based antioxidants. The phenoHc compounds react with the organic titanate to form a highly colored titanium phenolate. Replacement of 0.25 to 0.75 moles of acetylacetone with a malonic acid dialkyl ester, such as diethyl malonate, gives a titanium complex that maintains the performance advantages of the acetyl acetone titanium complexes, but which is only slightly yellow in color (505). These complexes still form highly colored titanium phenolates. 

Pyrazoles, isoxazoles and isothiazoles with a hydroxyl group in the 3-position (491 Z = NR, O, S) could isomerize to 3-azolinones (492). However, these compounds behave as true hydroxy derivatives and show phenolic properties. They give an intense violet color with iron(III) chloride and form a salt (493) with sodium hydroxide which can be O-alkylated by alkyl halides (to give 494 R = alkyl) and acylated by acid chlorides (to give 494 R = acyl). 

Of these four routes the first and third have been studied intensively, in particular in the preparation of the bis-phenol A polycarbonates. Since this polycarbonate is at present the only one of major commercial importance the following remarks will apply to this only unless otherwise stated. 

The second path in Fig. 3 outlines the approach to a more robust tape designed by Drew [21]. Here the milled rubber and filler are combined with tackifiers and other additives/stabilizers in an intensive dispersing step, such as a Mogul or Banbury mixer. Next, a phenolic resin or an alternative crosslinker is added and allowed to react with the rubber crosslinker to a point somewhat short of crosslinking. The compounded mixture is then charged to a heavy duty chum and dissolved in a suitable solvent like mineral spirits. To prepare a masking tape. 

Primary and secondary amines, amino acids and phenols react In the case of long-wavelength UV light (A = 365 nm) the DANS amides fluoresce yellow-green, while amines that have reacted at a phenolic OH group have an intense yellow to yellow-orange fluorescence The detection hmit for DANS amides is ca 10 mol [86]... 

In general no warming is necessary to produce the colored zones pyridoxine is colored intense blue, pyridoxamine violet and pyridoxal dark blue [1, 3]. Phenols... 

Note For some of the substances the intensities of coloration are only stable for ca. 2 h in the case of phenols the coloration intensifies during this time [2], The detection limits for indole derivatives lie in the lower nanogram range. 

A method that has been the standard of choice for many years is the Lowry procedure. This method uses Cn ions along with Folin-Ciocalteau reagent, a combination of phosphomolybdic and phosphotnngstic acid complexes that react with Cn. Cn is generated from Cn by readily oxidizable protein components, such as cysteine or the phenols and indoles of tyrosine and tryptophan. Although the precise chemistry of the Lowry method remains uncertain, the Cn reaction with the Folin reagent gives intensely colored products measurable spectrophotometrically. 

Shindo studied the hydrogen-bonding ability of a fairly long series of substituted pyridine 1-oxides with methanol in chloroform solution and found that the OH frequency of the hydrogen-bonded OH group in methanol is well correlated with the <7-values. For four compounds, the intensity of the same band is also well correlated. In a similar study the OH frequencies of phenol vary monotonically with the CT-values, but not in a linear fashion. 

The discovery of the utility of the bis-chromone carboxylic acid derivative cromolyn sodium in the treatment of asthma and related allergies has led to an intensive, and thus far not very fruitful, effort to discover analogues which would show oral activity in contrast to the lead which must be administered by inhalation. Preparation of a typical analogue, proxicromil (63), starts with the O-allylated phenol 57. Claisen rearrangement leads to the corresponding C-allylated product 58. 

Like most phenols, it gives an intense blue colour with solution of ferric chloride. By heating it with alcoholic potash and methyl iodide it is converted into methyl-chavicol or estragol, the characteristic constituent of tarragon oil. 

Molecular ion The molecular ions are very intense in phenol, methylphenol, and dimethylphenol. 

In Figure 13.2, the intensity of the ion at m/z 170 represents a molecular ion of an aromatic compound. The characteristic losses from the molecular ion (M - 1, M - 28, and M - 29) suggest an aromatic aldehyde, phenol, or aryl ether. The molecular formula of Ci2H 0O is suggested by the molecular ion at m/z 170, which can be either a biphenyl ether or a phenylphenol. The simplest test to confirm the structure is to prepare a TMS derivative, even though m/z 11 strongly indicates the diaryl ether. 

Network properties and microscopic structures of various epoxy resins cross-linked by phenolic novolacs were investigated by Suzuki et al.97 Positron annihilation spectroscopy (PAS) was utilized to characterize intermolecular spacing of networks and the results were compared to bulk polymer properties. The lifetimes (t3) and intensities (/3) of the active species (positronium ions) correspond to volume and number of holes which constitute the free volume in the network. Networks cured with flexible epoxies had more holes throughout the temperature range, and the space increased with temperature increases. Glass transition temperatures and thermal expansion coefficients (a) were calculated from plots of t3 versus temperature. The Tgs and thermal expansion coefficients obtained from PAS were lower titan those obtained from thermomechanical analysis. These differences were attributed to micro-Brownian motions determined by PAS versus macroscopic polymer properties determined by thermomechanical analysis. 

Figure 13, indicates that the first mole of phenol is released in <30 s, the same elapsed time for the chemiluminescence to reach a maximum intensity. In fact, the measured rate constant r, for the rise in the chemiluminescence emission, is identical to the rate of the first phenol s release from the oxalate ester. Furthermore, the slower rate of release of the second phenol ligand has a rate constant that is identical to the chemiluminescence decay rate f. Thus, the model allows a quantitative analysis of the reaction mechanism, heretofore not available to us. We intend to continue this avenue of investigation in order to optimize the chemiluminescence efficiencies under HPLC conditions and to delineate further the mechanism for peroxy-oxalate chemiluminescence. 

Intensely colored azo dyes are pro- [3, 17] duced. Catecholamines [20], imidazoles [21] and phenols also react. 

Phenols (capable of coupling) Fast blue salt B, fast blue salt BB, fast black salt K, diazotized sulfanilic acid (Pauly s reagent) diazotized sulfanilamide or 4-nitroaniline Intensely colored azo dyes are formed. Catecholamines [20, 3S], imidazoles [21] and amines capable of coupling also react. [3, 17]... 

Coupling reactions with diazonium salts to yield intensely colored azo derivatives have often been used for the detection of phenols, primary aromatic amines and electron-rich heterocyclics. 

Fast blue salt BB couples with phenols, preferably in alkaline medium, to yield intensely colored azo dyes. 

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