Phenol reacts with acetic anhydride in the presence of sodium acetate to produce the ester phenyl acetate: The CH_3COO- group of phenyl acetate, like the -OH group of phenol (Practice Problem 15.8), is an ortho-para director. PABLE I Pummecer I~erction in Acetic Anhydride Kinetic Data on a) Sulfoxide, O.4.6 x l0~ mole 1~, was :acted with acetic anhydride and no solvent was used. Phenol reacts with acetic anhydride in the presence of sodium acetate to produce the ester phenyl acetate: The CH_3COO- group of phenyl acetate, like the -OH group of phenol (Practice Problem 15.8), is an ortho-para director. The reacticn proceeded with 97.5% conversion of phenol and with the indicated selectivities to 4-hydroxyacetophenone (, 1. 17. Moreover product purification is simpler using such an aspect of this invention since considerably less than one mole of water per mole of phenol reactant need be removed from the product whereas close to one mole of acetic acid or water must be removed when the process utilizes about one mole of anhydride or acid per mole of phenol reactant. The product of the reaction was extracted with 10 mL ethyl acetate, 50 mL of water were added and the pH of the resulting aqueous phase was adjusted to 7.0 using a solution of 45% potassium hydroxide. How to synthesize aspirin without using acetic anhydride? 175 Torr (0.23 bar), 80 g (4.0 mol) of anhydrous hydrogen fluoride was added, and the mixture was warmed to 75°C and maintained at that temperature for 60 minutes without cooling it a second time to -30°C as described in Example 1. In carrying out the reaction, an inert gas such as nitrogen may be used to keep the reaction space under the desired pressure, about 2.5 to about 500 psig. The reaction proceeded with 99.9% conversion and with the indicated selectivities to phenyl acetate (0.0%), 4-hydroxyacetophenone (86.6%), 2-hydroxyacetophenone (6.3%), and 4-acetoxyacetophenone (1.6%). 0000001514 00000 n The procedure of Example 1 was repeated, but employing 40 molar equivalents of anhydrous hydrogen fluoride, a reaction temperature of 75°C and a reaction time of 60 minutes. The procedure of Example 11 was repeated, but employing 30 molar equivalents of anhydrous hydrogen fluoride. What can be the possible consequences? 0000315617 00000 n MOTT, GRAHAM NIGEL, Inventor name: The reaction proceeded with 99.6% conversion of phenol and with the indicated selectivities to phenyl acetate (0.0%), 4-hydroxyacetophenone (90.5%), 2-hydroxyacetophenone (7.8%), and 4-acetoxyacetophenone (1.1%). A 300 cc Hastelloy C autoclave was charged with 27.6 g (0.3 mol) of phenol, cooled to -30°C using a carbon dioxide/isopropanol bath, and then evacuated to ca. The fact that a maximum rate of acetylation of p -chlorophenol is reached as the pyridine concentration is increased is most readily interpreted in terms … and you may need to create a new Wiley Online Library account. 0000001863 00000 n And also, what are the roles of cyanobacteria and algae to convert CO2 for photosynthesis? The process of claim 8 wherein a phenol conversion of at least about 80% and a reaction selectivity to 4-hydroxyacetophenone of at least about 70% are obtained. All rights reserved. : ", Hydrogen fluoride as a condensing agent. If you took two ethanoic acid molecules and removed a molecule of water between them you would get the acid anhydride, ethanoic anhydride (old name: acetic anhydride). In one embodiment of the present invention, the preparation of 4-HAP by the acetylation of phenol with acetic acid using hydrogen fluoride as catalyst proceeds in accordance with the following equation (I): In carrying out the reaction so as to obtain particularly high yields of 4-HAP within this invention, phenol is reacted with about 0.9 to 1.4 moles, preferably about 1.0 to 1.25 moles of acetic acid per mole of phenol at a temperature of reaction of about 40 to 90°C, preferably about 50 to 80°C in the presence of hydrogen fluoride catalyst in an amount of about 20 to 50 moles, preferably about 25 to 30 moles, per mole of phenol for a reaction period of about 10 to 120 minutes, preferably about 30 to 75 minutes.

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