Phenols boiling point

Vacuum distillation recovers the unreacted cumene and yields a-methylstyrene, which can be hydrogenated back to cumene and recycled. Further distillation separates phenol, boiling point 181°C, and acetophenone, boiling point 202°C. 

Aromatic esters usually burn with a smoky flame, possess reasonably high boiling points, and are (particularly esters of phenols) sometimes crystalline solids. Phenyl esters usually give phenol upon distillation with soda hme (see Section IV,175 for general details). 

Some ortho substituted phenols such as o mtrophenol have significantly lower boiling points than those of the meta and para isomers This is because the intramolec ular hydrogen bond that forms between the hydroxyl group and the substituent partially compensates for the energy required to go from the liquid state to the vapor... 

The —OH group of phenols makes it possible for them to participate m hydrogen bonding This contributes to the higher boiling points and greater water solubility of phenolic compounds compared with arenes and aryl halides... 

The polymers dissolve in l,l,l,3,3,3-hexafluoro-2-propanol [920-66-1/, hot phenols, and /V, /V- dim ethyl form am i de [68-12-2] near its boiling point. The excellent solvent resistance notwithstanding, solvents suitable for measurement of intrinsic viscosity, useflil for estimation of molecular weight, are known (13,15). 

In a 250-ml. flask attached to a Vigreux column 30 cm. in over-all length ("Note 1) a mixture of 42.8 g. (0.2 mole) of phenyl salicylate ( Salol, m.p. 42-43°), 26.7 g. (0.25 mole) of o-tolui-dine, and 60 g. of 1,2,4-trichlorobenzene (m.p. 15-16°), is heated at the boiling point, so that the phenol formed slowly distils. The temperature rises from 183° to 187° during the first hour, and 22-23 g. of distillate is collected. Heating is continued until the temperature rises to 202° and a total of 45-46 g. of distillate has been collected (Note 2). The flask is then removed, and to it are added 3 g. of Norite and 10 nil. of trichlorobenzene. The mixture is heated to boiling and filtered hot by suction. The... 

When the boiling point of the amine is widely different from that of phenol, a diluent is unnecessary though it facilitates puri-... 

Although less common, azeotropic mixtures are known which have higher boiling points than their components. These include water with most of the mineral acids (hydrofluoric, hydrochloric, hydrobromic, perchloric, nitric and sulfuric) and formic acid. Other examples are acetic acid-pyridine, acetone-chloroform, aniline-phenol, and chloroform-methyl acetate. 

Furfural is a colourless liquid which darkens in air and has a boiling point of 161.7°C at atmospheric pressure. Its principal uses are as a selective solvent used in such operations as the purification of wood resin and in the extraction of butadiene from other refinery gases. It is also used in the manufacture of phenol-furfural resins and as a raw material for the nylons. The material will resinify in the presence of acids but the product has little commercial value. 

In extractive distillation, the compounds which it is desired to separate are distilled in the presence of a solvent. This solvent, by reason of its greater affinity for one of the compounds, causes the other material present to exhibit an abnormally high vapor pressure which permits its removal from the system. For example, adding phenol to a mixture of toluene and close-boiling paraffins and naphthenes causes the toluene to behave as if it boiled as much as 40 °F above its normal boiling point. 

Aprotic polar solvents have to be used for several reasons. They are often good solvents for both monomers (including phenolates) and amorphous polymers. In addition, they can also stabilize the Meisenheimer intermediates. Common aprotic polar solvents, such as DMSO, /V,/V-dimcthyl acetamide (DMAc), DMF, N-methyl pyrrolidone (NMP), and cyclohexylpyrrolidone (CHP) can be used. Under some circumstances, very high reaction temperature and boiling point solvents such as sulfolane and diphenyl sulfone (DPS) have to be used due to the poor reactivity of the monomers or poor solubility of the resulting, possibly semicrystalline polymers, as in the PEEK systems. 

Many of the phenols which are used in household and other commercial disinfectant products are produeed from the tar obtained by distillation of coal or more recently petroleum. They are known as the tar acids. These phenols are separated by fractional distillation according to their boiling point range into phenol, cresols, xylenols and high boiling point tar acids. As the boiling point increases the properties of the products alter as shown ... 

The phenols from the higher boiling point fractions have greater antimicrobial activity but must be formulated so as to overcome their poor solubility. A range of solubilized and emulsified phenolic disinfectants are available including the clear soluble fluids,... 

The tuning of solubility with a relatively small jump or fall in pressure can possibly bestow many benefits with respect to rates, yields, and selectivity. Reaction parameters can be changed over a wide range. Replacement of solvents with high boiling points by supercritical (SC) fluids offers distinct advantages with respect to removal of the solvent. SC fluids like CO2 are cheap and environmentally friendly the critical temperature of CO2 is 31 C and the critical pressure 73.8 atm (Poliakoff and Howdle, 1995). Eckert and Chandler (1998) have given many examples of the use of SC fluids. Alkylation of phenol with tcrt-butanol in near critical water at 275 °C allows 2- erf-butyl phenol to be formed (a major product when the reaction is kinetically controlled 4-rert-butyl phenol is the major product, when the reaction is... 

A. Ethyl 3-methylcoumarilate. Dry sodium phenolate (116 g., 1 mole) (Note 1) and 1 1. of dry thiophene-free benzene (Note 2) arc placed in a 2-1. three-necked flask fitted with mechanical stirrer, dropping funnel, and reflux condenser with drying tube. The suspension is heated to the boiling point on the steam bath, heating is moderated, and 165 g. (1 mole) of ethyl a-chloroaceto-acetate (Note 3) is added with stirring through the dropping... 

To add to the cost further, many of these compounds are rather sensitive to temperature and would decompose before vaporizing. For example, oil of cloves (from Eugenia caryophyllata) is rich in the phenol eugenol (V), which has a boiling point of 250 °C). We cannot extract the oils via a conventional distillation apparatus. 

The same reaction can be applied, not only to the aromatic parent substances, the hydrocarbons, but also to all their derivatives, such as phenols, amines, aldehydes, acids, and so on. The nitration does not, however, always proceed with the same ease, and therefore the most favourable experimental conditions must be determined for each substance. If a substance is very easily nitrated it may be done with nitric acid sufficiently diluted with water, or else the substance to be nitrated is dissolved in a resistant solvent and is then treated with nitric acid. Glacial acetic acid is frequently used as the solvent. Substances which are less easily nitrated are dissolved in concentrated or fuming nitric acid. If the nitration proceeds with difficulty the elimination of water is facilitated by the addition of concentrated sulphuric acid to ordinary or fuming nitric acid. When nitration is carried out in sulphuric acid solution, potassium or sodium nitrate is sometimes used instead of nitric acid. The methods of nitration described may be still further modified in two ways 1, the temperature or, 2, the amount of nitric acid used, may be varied. Thus nitration can be carried out at the temperature of a freezing mixture, at that of ice, at that of cold water, at a gentle heat, or, finally, at the boiling point. Moreover, we can either employ an excess of nitric acid or the theoretical amount. Small scale preliminary experiments will indicate which of these numerous modifications may be expected to yield the best results. Since nitro-compounds are usually insoluble or sparingly soluble in water they can be precipitated from the nitration mixture by dilution with water. 

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