Ethylation, of phenol

The pioneering study of ruthenium-catalyzed regioselective alkylation using olefins as an alkylating reagent was reported by Lewis and Smith [24]. The ortho-selective ethylation of phenols with ethylene can be attained with the aid of a ruthenium(II) phosphite complex as a catalyst. This alkylation takes place exclusively at the position ortho to the hydroxyl group, and the corresponding 1 2 addition product is the major product (Eq. 6). The use of potassium phe-noxide is the key in this catalytic reaction. Unfortunately, however, the applicability of this reaction is narrow. Thus, phenol is the only applicable substrate in this reaction. 

Even in the alkylation of phenols and aromatic halides similar effects on orientation have been observed. Thus, the ethylation of phenol with ethanol and aluminum chloride yields the o- and p-derivatives, whereas with ethyl ether as the alkylating agent at a higher temperature 3,5-diethylphenol is obtained. Alkylation of chlorobenzene with ethanol and aluminum chloride at 80-90 yields p-chloroethylbenzene, but with ethylene at 100 , the principal product is the w-isomer. ... 

CgHgNOs. Yellow crystals m.p. 58 C, b.p. 283 C. Prepared by the ethylation of />-nitro-phenol with ethyl chloride. It is used for preparing p-phenetidine. 

Dissolve 3-8 g. of sodium in 75 mi. of rectified spirit, using otherwise the same conditions as in the preparation of anisole. Then add 15 g. of phenol, and to the clear solution add 13 2 ml. (19-1 g., n mois.) of ethyl bromide. Continue precisely as in the preparation of anisole, shaking the ethereal extract with sodium hydroxide solution as before in order to eliminate any unchanged phenol. Finally collect the fraction boiling at 168-172°. Yield, 14 g. 

Methyl and ethyl ethers of phenols are most conveniently prepared by alkylation with dimethyl sulphate and diethyl sulphate respectively in weakly alkaline solution, for example ... 

Ethyl bis-(2,4-dinitrophenyl) acetate (indicator) the stock solution is prepared by saturating a solution containing equal volumes of alcohol and acetone with the indicator pH range colorless 7.4-9.1 deep blue. This compound is available commercially. The preparation of this compound is described by Fehnel and Amstutz, Ind. Eng. Chem., Anal. Ed. 16 53 (1944), and by von Richter, Ber. 21 2470 (1888), who recommended it for the titration of orange- and red-colored solutions or dark oils in which the endpoint of phenol-phthalein is not easily visible. The indicator is an orange solid which after crystallization from benzene gives pale yellow crystals melting at 150-153.5°C, uncorrected. 

Coumarin can also be formed by the reaction of phenol with diketene (40). Similarly, diphenols can react with hydroxycarboxyUc acids or beta-ketoesters to give hydroxycoumaria derivatives. The reaction of resorciaol with malic acid produces umbeUiferone (7-hydroxycoumaria) and its reaction with ethyl acetoacetate gives beta-methylumbeUiferone (7-hydroxy-4-methylcoumaria). 

Another elastomer to find use is the substitution product of phenol and -ethylphenol along with an aHylic monomer to provide cross-link sites (5). This is trademarked EYPEL-A elastomer [66805-77-4] by Ethyl Corp., and designated PZ by ASTM. The substitution ratio is roughly 52 mol % phenol, 43% j )-ethylphenol, and 5% aHylic substituent. 

Several examples of cost-effective liquid-hquid extraction processes include the recovery of acetic acid from water (Fig. 15-1), using ethyl ether or ethyl acetate as described by Brown [Chem. Eng. Prog., 59(10), 6.5 (1963)], or the recoveiy of phenolics from water as described by Lauer, Littlewood, and Butler [7/Steel Eng., 46(5), 99 (1969)] with butyl acetate, or with isopropyl ether as described by Wurm [Gliickauf, 12, 517 (1968)], or with methyl isobutyl ketone as described by Scheibel [ Liqmd-Liquid Extraction, in Periy Weiss-... 

Muconic acid has been obtained in a variety of ways. The procedures that seem most important from a preparative point of view are by treatment of ethyl o ,5-dibromoadipate with alcoholic potassium hydroxide, by condensation of glyoxal (as the sodium bisulfite addition product) with malonic acid, by heating ethyl l-acetoxy-l,4-dihydromuconate (obtained by condensing ethyl oxalate and ethyl crotonate, acetylating, and reducing),and by oxidation of phenol with peracetic acid. ... 

Nitrile rubber/phenolic resin blends. Blends of equal parts by weight of a nitrile rubber and a phenolic resin in methyl ethyl ketone (at a 20-30 wt% total solids content) is suitable for many adhesive purposes. The more phenolic resin in the formulation, the greater the bond strength and brittleness of the NBR adhesive [67]. Table 10 shows the effect of phenolic resin on nitrile rubber properties. On the other hand, the higher the acrylonitrile content in the rubber. 

Obtain the TLVs for the following chemicals carbon tetrachloride, chlorobenzene, iodine, ethyl formate, phenol, methanol, and MEK (methyl ethyl ketone). Rank these in order of greatest health risk. Here s a chance for you to become acquainted with some of the Web sites referred to earlier. 

It is obtained by allowing a solution of one molecule of phenol-acetic -ester in three to four times its weight of absolute alcohol, to fall in drops on a quantity of sodium calculated for six atoms. It is then heated for several hours on an oil-bath, until the sodium has disappeared, if necessary adding more alcohol. After cooling, water is added, and the ester which is not attacked is saponified. The alcohol and phenyl-ethyl alcohol are then distilled off with steam, when the latter is at once obtained in the pure state. 

Make Useful Coproducts. The success of this approach to process development is heavily dependent on the market situation but in suitable cases where there is market demand for the total output of both products such processes can be successful. Examples here are the coproduction of phenol and acetone, which is essentially noncatalytic, and the more recently developed process for the cooxidation of ethyl benzene and propylene to produce propylene oxide and styrene. 

This procedure provides a convenient method for the esterification ol a wide variety of carboxylic acids. The reaction proceeds smoothly with sterically hindered acids6 and with acids which contain various functional groups. Esters are obtained in high purity using Kugelrohr distillation as the sole purification technique. In cases where traces of dichloromethane present no problems, the crude product is usually pure enough to be used directly in subsequent reactions. Methyl and ethyl ethers of phenols may also be prepared by this procedure (see Note 8). 

The methyl ether was introduced after the Wittig reaction which used a protected carboxylic acid (ethyl ester). p-Nitrophenol is available and is one of the products of the nitration of phenol. 

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