Phenol solution preparation

Aminoantipyrine-phenol solution. Prepare by dissolving 810 mg phenol (Caution) in 40 mL of glass-distilled water and adding 25 mg of 4-aminoantipyrine. Dilute to a final volume of 50 mL with glass-distilled water. 

Into fiask II 25 ml of standard cresol or phenol solution prepared as described below. 

The evidence outlined strongly suggests that nitration via nitrosation accompanies the general mechanism of nitration in these media in the reactions of very reactive compounds.i Proof that phenol, even in solutions prepared from pure nitric acid, underwent nitration by a special mechanism came from examining rates of reaction of phenol and mesi-tylene under zeroth-order conditions. The variation in the initial rates with the concentration of aromatic (fig. 5.2) shows that mesitylene (o-2-0 4 mol 1 ) reacts at the zeroth-order rate, whereas phenol is nitrated considerably faster by a process which is first order in the concentration of aromatic. It is noteworthy that in these solutions the concentration of nitrous acid was below the level of detection (< c. 5 X mol... 

The diazonio group can also be replaced by —OH to yield a phenol and by —H to yield an arene. A phenol is prepared by reaction of the arenediazonium salt with copper(I) oxide in an aqueous solution of copper(ll) nitrate, a reaction that is especially useful because few other general methods exist for introducing an -OH group onto an aromatic ring. 

Phenol, once known as carbolic acid, HC6H50, is a weak add. It was one of the first antiseptics used by lister. Its K, is 1.1 X 10-1C. A solution of phenol is prepared by dissolving 14.5 g of phenol in enough water to make 892 mL of solution. For this solution, calculate... 

Standard phenol solution ( 0.025 mg LT1). Dilute 25.0 mL of the stock solution to 1.0 L using freshly boiled and cooled distilled water. This solution must be freshly prepared. 

Procedure. Prepare four test solutions of phenol by placing 200 mL of boiled and cooled distilled water in each of four stoppered, 500 mL bottles, and adding to each 5g of sodium chloride this assists the extraction procedure by salting out the phenol. Add respectively 5.0, 10.0, 15.0 and 20.0 mL of the standard phenol solution to the four bottles, then adjust the pH of each solution to about 5 by the careful addition of 5M hydrochloric acid (use a test-paper). Add distilled... 

The rare earth oxides of lanthanum, samarium and gadolinium were converted into soluble nitrate salts by dissolving them in the minimum amount of concentrated nitric acid. Then two sets were prepared by adding 2.0 ml of aqueous solution of La(N03)3.6H20 [0.2 M] and 0.01 ml of (n-BuO)4Ti to 25 ml of aqueous solution of Cu(N03)2 [1.0 M]. Similarly, two sets were prepared with Co(N03)3. Same procedures were followed for Sm(N03)3 [0.2 M] and Gd(N03)3 [0.2 M], One set of all these solutions were sonicated under ultrasonic bath (Model - Meltronics, 20 kHz, 250 W) for half an hour. The solutions prepared in normal and sonicated conditions were kept in muffle furnace (Model - Deluxe Zenith) first at 100°C for 2 h and then the temperature of the furnace was raised up to 900°C and calcined for 2 h. The solid composites prepared were then cooled to room temperature and treated as catalyst for phenol degradation. 

Method of Preparation Dissolve 1 g of phenol and 4 mL of liquid Br2 separately in 10-15 mL of glacial acetic acid. Add Br2 solution to phenol solution until the decolourisation of bromine ceases. Allow the mixture to stand for 20 min and add more bromine solution, if the colour faded. Pour the liquor into 70 mL of water and filter the product. Wash with water and recrystallise in ethanol. 

Experiments.—To an ice-cooled solution of 2-3 g. of a phenol (phenol, cresol, /3-naphthol, salicylaldehyde, quinol) in a little ether, acetone, or methyl alcohol, the diazomethane solution prepared as described above is added in small portions until evolution of gas no longer takes place and the solution is coloured faintly yellow. 

A 4.37-mg sample of protein was chemically digested to convert its nitrogen into ammonia and then diluted to 100.0 mL. Then 10.0 mL of the solution were placed in a 50-mL volumetric flask and treated with 5 mL of phenol solution plus 2 mL of sodium hypochlorite solution. The sample was diluted to 50.0 mL, and the absorbance at 625 nm was measured in a 1.00-cm cuvet after 30 min. For reference, a standard solution was prepared from... 

Phenol red in buffer it is most efficient to have a solution of phenol red prepared in each pH buffer to be used. Concentration = 1.0 g of phenol red/100 mL of buffer. 

An aqueous solution of the substance is gently warmed, when a vigorous evolution of nitrogen occurs, and a dark coloured oil, smelling strongly of phenol, separates. It can be extracted with ether and tested for phenol (see Preparation 352). 

Dissolve 1.0 g of the compound in 10-15 ml of glacial acetic acid, cautiously add a solution of 3-4 ml of liquid bromine in 10-15 ml of glacial acetic acid until the colour of bromine persists and allow the mixture to stand for 15-20 minutes. Pour into 50-100 ml of water, filter off the bromo compound at the pump and wash with a little cold water. Recrystallise from dilute ethanol. Alternatively dissolve 1.0 g of the phenol in water, ethanol or acetone and add slowly, with constant shaking, just sufficient of a bromine solution (prepared by adding 5g of bromine to a solution of 7.5 g of potassium bromide in 50 ml of water) to impart a yellow colour to the mixture. Allow to stand for 5 minutes. Add about 50 ml of water, and shake vigorously to break up any lumps. Filter and wash the bromo derivative with a dilute solution of sodium metabisulphite. Recrystallise from ethanol or from dilute ethanol. 

Commercial phenyllithium does not give satisfactory results. Phenyllithium solutions prepared as described herein should be used within 24 hours. The major impurities that appear in the product are phenol and biphenyl which result from decomposition and coupling reactions of the lithium reagent. 

Procedure Transfer the Sample Solution, prepared as directed in the individual monograph, into a separator, and unless otherwise directed, add 6 mL of Ammonium Citrate Solution and 2 mL of Hydroxylamine Hydrochloride Solution. (Use 10 mL of the citrate solution when determining lead in iron salts.) Add 2 drops of phenol red TS to the separator, and make the solution just alkaline (red in color) by the addition of ammonium hydroxide. Cool the solution, if necessary, under a stream of tap water, then add 2 mL of Potassium Cyanide Solution. Immediately extract the solution with 5-mL portions of Dithizone Extraction Solution, draining each extract into another separator, until the dithizone solution retains its green color. Shake the combined dithizone solutions for 30 s with 20 mL of 1 100 nitric acid discard the chloroform layer add 5.0 mL of Standard Dithizone Solution and 4 mL of Ammonia-Cyanide Solution to the acid solution and shake for 30 s. The purple hue in the chloroform solution of the sample caused by any lead dithizonate present does not exceed that in a control, containing the volume of Diluted Standard Lead Solution equivalent to the amount of lead specified in the monograph, when treated in the same manner as the sample. 

Resol-type phenol resin adhesives were also prepared from wood-phenol solutions liquified at ISO C with phenolsulfonic acid catalyst and their gluabili-ties were examined [12]. The results revealed that when these adhesives were used, it was easily possible to realize completely satisfactory waterproof... 

The third application example is Novolak resin-type moldings prepared from untreated wood-phenol solutions [29,30]. After one part of wood meal had been liquified in two parts of phenol, the unreacted phenols were distilled... 

Replacement of halogen atoms by alkoxy groups may be hindered in N(7)- and N(9)-unsubstituted purines because of anion formation although this has been overcome to some extent by use of antimony chloride followed by the alcohol (71MI40904). Aryloxypurines have similarly been prepared from halogenopurines and hot alkaline phenol solutions. Since alkylation of oxopurines tends to lead almost exclusively to Af-alkyl derivatives (see Section 4.09.5.2.2(iv)), direct replacement of halogen atoms assumes special importance as a route to the alkoxypurine derivatives. 

---