Phenols reaction with acetone

In contrast to aliphatic alcohols, which are mostly less acidic than phenol, phenol forms salts with aqueous alkali hydroxide solutions. At room temperature, phenol can be liberated from the salts even with carbon dioxide. At temperatures near the boiling point of phenol, it can displace carboxylic acids, e.g. acetic acid, from their salts, and then phenolates are formed. The contribution of ortho- and -quinonoid resonance structures allows electrophilic substitution reactions such as chlorination, sulphonation, nitration, nitrosation and mercuration. The introduction of two or three nitro groups into the benzene ring can only be achieved indirectly because of the sensitivity of phenol towards oxidation. Nitrosation in the para position can be carried out even at ice bath temperature. Phenol readily reacts with carbonyl compounds in the presence of acid or basic catalysts. Formaldehyde reacts with phenol to yield hydroxybenzyl alcohols, and synthetic resins on further reaction. Reaction of acetone with phenol yields bisphenol A [2,2-bis(4-hydroxyphenyl)propane]. 

Chloramine, which is formed as the first step of the reaction, reacts with phenol to yield quinonechloramine. This reacts with another phenol molecule to give indophenol. The blue colour is due to the indophenol anion, formed in alkaline medium. The intensity of the blue colour is greatly increased by adding a little acetone (-0.2 ml of acetone per 25 ml of solution). The molar absorptivity at A.max = 625 nm is 4.5T0 (a = 0.32). 

Improvements with respect to activity, selectivity, and over-all productivity (see fig. 3) of the catalyst in the condensation reaction of acetone with phenol have been demonstrated using specially designed Deloxan ASP catalysts (10). 

The first, and still the most important, commercial epoxide resins are reaction products of bis-phenol A and epichlorhydrin. Other types of epoxide resins were introduced in the late 1950s and early 1960s, prepared by epoxidising unsaturated structures. These materials will be dealt with in Section 26.4. The bis-phenol A is prepared by reaction of the acetone and phenol (Figure 26.1). 

Mono-substitution occurs most readily in the stepwise replacement of the halogen substituents of 2,4,6-trichloro-s-triazine with aqueous methanol and sodium bicarbonate (30°, 30 min), the monomethoxy derivative (324) is obtained on heating (65°, 30 min), the disubstitu-ted derivative is formed and on brief heating (65°) with the more basic sodium carbonate or methanolic sodium hydroxide (25°, 3 hr) complete methoxylation (320) occurs. Ethanolic ethoxide (25°, 1 hr) or sodium carbonate (35°) is sufficient to give complete ethoxy-dechlorination. The corresponding phenoxy derivatives are obtained on treatment with one (0°), two (15°, 1 hr), or three equivalents (25-70°, 3 hr) of various sodium phenoxides in aqueous acetone. The stepwise reaction with phenols, alcohols, or thiols proceeds in better yield in organic solvents (acetone or chloroform) with collidine or 2,6-lutidine as acid acceptors than in aqueous sodium bicarbonate. ... 

Today, most acetone is obtained via a cumene hydroperoxide process where it is coproduced with phenol. This reaction is noted in Chapter 10. 

Bisphenol A is a solid material in the form of white flakes, insoluble in water but soluble in alcohols. As a phenolic compound, it reacts with strong alkaline solutions. Bisphenol A is an important monomer for producing epoxy resins, polycarbonates, and polysulfones. It is produced by the condensation reaction of acetone and phenol in the presence of HCI. (See Chapter 10, p. 273)... 

The Hock process includes the oxidation of cumene by air to hydroperoxides using large bubble columns and the cleavage of the hydroperoxide via acid catalysis, which is reaction [OS 82]. This process is used for the majority of world-wide phenol production and, as a secondary product, also produces large quantities of acetone [64]. Phenol is used, e.g., for large-scale polymer production when reacted in a polycondensation with formaldehyde. 

Dansyl chloride is the most widely used of the derivatizing reagents. It forms derivatives with primary and secondary amines readily, less rapidly with phenols and imidazoles, and very slowly with alcohols. The reaction medium is usually an aqueous-organic sixture (e.g., 1 1 acetone-water) adjusted to a pH of 9.5-10. Dansyl chloride has two major application areas. It is used to determine small amounts of amines, amino acids and phenols, as... 

We have found several examples in which adjacent cationic charge centers are shown to activate carboxonium electrophiles. A convenient method for studying this activation is through the use of the hydroxyalkylation reaction, a commercially important, acid-catalyzed condensation of aldehydes and ketones with arenes.10 It is used for example in the synthesis of bis-phenol A from acetone and phenol (eq 6). While protonated acetone is able to react with activated arenes like phenol, it is not capable of reacting with less nucleophilic... 

The intermediate tertiary carbinol could not be detected (with the exception of bis(trifluoromethyl)(hydroxyphenyl)carbinol from hexafluoro-acetone and phenol [395]) and reacts readily with another molecule of phenol this second stage of the reaction is, in fact, an alkylation of phenol by the tertiary carbinol, or by the carbonium ion formed from it, by a common carbonium ion alkylation mechanism (Sect. 3.3). 

There have been reviews of nucleophilic substitution103 and of deoxidative nucleophilic substitution 104 in heterocyclic A -oxidcs. Stable carbon-carbon-bonded adducts, such as (22), have been reported from the reactions of 6-phenyl-1,2,4-triazine 4-oxides with phenols oxidation of the adducts may be achieved by reaction with potassium permanganate in acetone.105... 

Protonation of acetone makes a carbocation that can react as an electrophile in sequential electrophilic aromatic substitution reactions with phenol. 

Ester-based cascades (e.g., 107) have been prepared[77 80i by using 5-(tert-butyldime-thylsiloxy)isophthaloyl dichloride (108), which was synthesized in high yield from 5-hydroxy-isophthalic acid (Scheme 5.26). The dendron wedges were prepared by treatment of siloxane 108 with phenol to give bis(aryl ester) 109, which was hydrolyzed, or desilylated (HC1, acetone), to generate a new phenolic terminus. Treatment of this free phenolic moiety with monomer 108, followed by hydrolysis, afforded the next tier (110). Repetition of the sequence followed by reaction of the free focal phenols with a triacyl chloride core, (e.g., 86), afforded the fourth tier dendrimer 107 of the polyester aryl series. It was noted that the choice of base (N, A-dimethylaniline) used in the final esterification was critical, since with pyridine bases (pyridine or 4-(dimethylamino)pyridine) facile transesterification resulting in branch fragmentation occurred. 

Besides, furfural polymerizes in the presence of an acid catalyst with phenol, urea, and acetone. In this regard, the phenol-furfural and urea-furfural resins are important [221-223], Furfural reacts usually as does all a-substituted aldehydes in this regard, with phenol it condenses in the presence of either alkali or acid to form synthetic resins in a reaction that is very similar to that of phenol with formaldehyde or acetaldehyde [223],... 

A high ECD response is also provided by 2,4-dinitrophenyl ethers, for which various methods of preparation were reported by Cohen et al. [63]. A 4-ml volume of acetone containing phenols (ca. 10 yjg), 0.1 ml of a saturated methanolic solution of sodium methanolate and 1 ml of l-fluoro-2,4-dinitrobenzene in acetone (1%, w/v) were refluxed in a 10-ml flask for 30 min. The reaction mixture was then added to 25 ml of sodium hydroxide solution (2.5%, w/v), diluted with a small volume of water and extracted with 25 ml of chloroform. After being dried with anhydrous sodium sulphate, the extract was carefully evaporated and the residue was dissolved in acetone and injected into the chromatograph. 

Bisphenol A is an important component of many polymers, including polycarbonates, polyurethanes, and epoxy resins. It is synthesized from phenol and acetone with HC1 as a catalyst. Propose a mechanism for this reaction. 

An important example is the reaction of prenyl bromide with phenols. This is simply carried out with K2CO3 in acetone as phenols are acidic enough (pKa 10) to be substantially deprotonated by carbonate. The product is essentially entirely from the S>f2 route, and is used in the Claisen rearrangement (Chapter 36). 

Bisphenol is obtained by the reaction of phenol and acetone with HC1 or acid resin as catalyst. In the HC1 catalyzed process (Fig. 10.34), phenol and acetone in a molar ratio of about 3 1 are charged to an acid-resistant stirred reactor. A sulfur-containing catalyst is added, and then dry HC1 gas is bubbled into the reaction mass. The temperature is maintained at 30 10oC for 8-12 hr. At the end of the reaction, the mixture is washed with water and treated first with enough lime to neutralize the free acid. Vacuum and heat... 

Indeed. Mannich aminomcthylation represents the repetitive-cumulative reaction giving rise to several types of formaldehyde resins the most relevant of these are melamine resins, which have been abundantly investigated and reported in a quite large series of patents. Melamines, as well as guanamincs, have also been tested in combination with phenols or urea derivatives, behaving as Mannich substrates in this type of reaction. Further examples of Mannich polymerization involving other amines and acetonic, phenolic, etc., substrates arc found in Chap. Ill, A (sec also 425, Chap. I1I.C.I). 

Most acetone is manufactured today in the United States by thermochemical cumene oxidation. It is a co-product with phenol. Acetone is also manufactured by dehydrogenation of 2-propanol, which is made by hydration of propylene. Most 1-butanol is manufactured today by hydrogenation of n-butyraldehyde, which is obtained by the hydroformylation of propylene (0x0 reaction). It is also manufactured by hydrogenation of crotonaldehyde, which is obtained by the... 

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