Ethyl benzene from acetophenone

Reactions of 2-chloro- and 2,3-dichloroquinoxalines with carbanions give 2-quinoxalinyl ketones and 3-chloro-2-quinoxalinyl ketones, respectively e.g., 2-quinoxalinylacetophenone (151) from acetophenone anion.161 However, 2,3-dimethoxy- and 2,3-diethoxy-quinoxaline with methyl ethyl ketone and sodamide in anhydrous benzene give 2-amino derivatives rather than ketones.162... 

Problem 12.1 How might you prepare ethylbenzene from (a) benzene and ethyl alcohol (b) acetophenone, C6H5COCH3 (c) styrene, C5H5CH=CH2 ... 

In an unpubhshed study, SPME and a 65p,m PDMS/DVB fiber were apphed for extraction of polystyrene (PS) thermo-oxidation products. As seen in Fig. 4, styrene monomer was the main compoimd migrating from the virgin material after low temperatme thermo-oxidation at 80 °C. After 20 weeks, new low molecular weight compoimds including toluene, ethyl benzene, benzaldehyde and acetophenone were also identified. Volatiles migrating from poly(vinyl chloride)/polycaprolactone-carbonate (PVC/PCL-PC) during thermo-oxidation were extracted by PDMS/DVB fiber [19]. The identified compounds included degradation products of PCL-PC, i.e.,... 

Fig. 8.38 Chemo-bio cascade catalysis for hydrogenation of acetophenone (A), followed by acylation of the formed ff-1-phenyl ethyl alcohol (B) with ethylacetate (Q) to / -1-phenyl ethyl acetate (P) other products were S-1 -phenyl ethyl alcohol (C), ethanol (I), and ethyl benzene (F). (From S. Sahin, J. Wdrna, P. Maki-Arvela, T. Salmi, D.Yu. Murzin, Kinetic modeling of lipase-mediated one- pot chemo-bio cascade synthesis of R- 7 -phenyl ethyl acetate starting from acetophenone, J. Chem. Technol. Biotechnol. 85 (2010) 192-198. Copyright 2010 Wiley).

The ketones are readily prepared, for example, acetophenone from benzene, acetyl chloride (or acetic anhydride) and aluminium chloride by the Friedel and Crafts reaction ethyl benzyl ketones by passing a mixture of phenylacetic acid and propionic acid over thoria at 450° and n-propyl- p-phenylethylketone by circulating a mixture of hydrocinnamic acid and n-butyric acid over thoria (for further details, see under Aromatic Ketones, Sections IV,136, IV,137 and IV,141). 

Other methods of preparing flavone include the action of ethanolic alkali on 2 -acetoxy-a,/3-dibromochalcone 7 Claisen condensation of ethyl o-ethoxybenzoate and acetophenone, and cyclization of the resulting 1,3-diketone with hydriodic acid 8 and treatment of 3-bromoflavanone with potassium hydroxide in ethanol.9 Flavone has also been prepared from ethyl phenyl-propiolate by condensation with sodium phenoxide and subsequent cyclization with phosphorus pentachloride in benzene 10 by fusing o-hydroxyacetophenone with benzoic anhydride and sodium benzoate 11 by the dehydrogenation of 2 -hydroxychal-cone with selenium dioxide 12 and by the action of alkali on flavylium chloride.13... 

We have prepared two series of oximes and studied their association by the cryosoopic method in benzene solution. The first series was derived from acetone oxime by substituting one of the methyl groups by ethyl, isopropyl, iert-butyl, cyolohexyl or phenyl. The seoond series consisted of para-substituted acetophenone oximes. 

In a 1-1. three-necked round-bottomed flask fitted with a Hershberg stirrer and a constant water separator (Note 1) surmounted by a reflux condenser are placed 120 g. (1 mole) of acetophenone, 113 g. (1 mole) of ethyl cyanoacetate (Note 2), 15.4 g. (0.2 mole) of ammonium acetate, 48.0 g. (0.8 mole) of glacial acetic acid, and 200 ml. of benzene. The reaction mixture is stirred and heated under reflux for 9 hours during which time 28-33 ml. of lower layer is collected in the water separator (Note 3). To the cooled reaction mixture is added 100 ml. of benzene, and the whole is extracted with three 10()-ml. portions of water. The combined aqueous layers arc extracted with 30 ml. of benzene, which is then added lo the organic layer from the previous... 

Friedel-Crafts reaction. A type of reaction involving anhydrous aluminum chloride and similar metallic halides as catalysts, discovered in 1877 by Charles Friedel, a French chemist (1832-1899), and James Mason Crafts, an American chemist (1830-1917), during joint research in France it has been developed since then for many important industrial uses, exemplified by the condensation of ethyl chloride and benzene to form ethylbenzene and the manufacture of acetophenone from acetyl chloride and benzene. The name is now applied to a wide variety of acid-catalyzed organic reactions. 

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