Ethyl benzylation

A) (i) Distillate. Test for the alcohol. e.g., methyl, ethyl, benzyl, or cyclohexyl alcohol. 

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). 

The dibenzyl ketone has a very high b.p. (ca. 200°/21 mm.) and this remains in the flask when the unsymmetrical ketone has been removed by distillation. The dialkyl ketone has a comparatively low b.p. and is therefore easily removed by fractionation under normal pressure acetone is most simply separated by washing with water. In this way methyl benzyl ketone (R = CHj), ethyl benzyl ketone (R = CHgCH,) and n-propyl benzyl ketone (R = CHjCHjCH,) are prepared. By using hydrocinnamic acid in place of phenylacetic acid ... 

Ethyl benzyl ketone. Use 204 g. of phenylacetic acid (m.p. 77°) and 333 g. (335 -5 ml.) of propionic acid (b.p. 139-141°), but omit the extraction with benzene when working up the distillate. Distil the dried... 

Me2Sn(SMe)2, BF3-Et20, PhCH3, 0°, 3-24 Ji AcOH, 75-100% yield." An ethyl ester can be hydrolyzed in the presence of an MEC ester with 1 N aqueous NaOH-DMSO (1 1), and MEC esters can be cleaved in the presence of ethyl, benzyl, cinnamyl, and t-butyl esters as well as the acetate, TBDMS and MEM ethers. 

Chemical Name 4-hydroxy-3,5-diiodo-0 -[1-[(1-methyl-3-phenylpropyl)amino] ethyl] benzyl alcohol... 

Benzylacetophenone has been prepared by the reduction of benzalacetophenone with zinc and acetic acid1 and catalytic-ally with palladium and hydrogen 2 by the reduction of /3-duplo-benzylidene acetophenone monosulfide 3 by the oxidation of the corresponding car bind with chromic acid 4 by the hydrolysis of ethyl benzyl benzoylacetate 5 from acetophenone and benzyl chloride by the action of sodamide 6 and from benzoic and hydrocinnamic adds using as catalysts manganese oxide 7 and ferric oxide.8... 

By adding one equivalent of alcohol to CDI at room temperature with or without base it is possible to isolate the imidazole-iV-carboxylate, which then reacts with a second mole of ROH to yield the carbonate. As in the case of alcoholysis of imidazolides, the reaction can be accelerated so effectively with catalytic amounts of NaOC2H5 or ImNa that it takes place in most cases exothermically, even at room temperature. However, tert-butyl alcohol, even when in excess, affords with CDI and base catalysis at room temperature only the imidazole-N-tert-butylcarboxylate, obviously for steric reasons. At higher temperature the carbonic ester is formed. Mixed carbonates such as ethyl benzyl carbonate or ethyl terf-butyl carbonate can be prepared with two different alcohols added sequentially.C9],[229]... 

Ethyl Benzyl Ether [Brpnsted Acid Promoted Reduction of an Aldehyde to an Unsymmetrical Ether].327 To a cooled mixture of benzaldehyde (4.3 g, 41 mmol) and absolute ethanol (3.7 g, 80 mmol) was added trichloroacetic acid (18.2 g, 111 mmol). Et3SiH (6.96 g, 60 mmol) was then added dropwise with stirring while the mixture was maintained at 50-60°. After 4 hours, the reaction mixture was diluted with water, neutralized with aqueous NaHC03 solution, and extracted with Et20. The dried ether extract was distilled and the 170-190° fraction was collected. Distillation from sodium gave ethyl benzyl ether 4.8 g (90%) bp 187-189°. 

The propensity of S-S dications to undergo dealkylation was found to decrease in the order of methyl > ethyl > benzyl. This order of reactivity parallels the increase in the stability of the corresponding carbocations.94 Dealkylation of dication 77 affords thiosulfonium salt 78 in quantitative yield.95 Kinetic studies suggest SN1 mechanism of dealkylation. In addition, reaction of sulfoxide 79 with a substituent chiral at the a-carbon results in racemic amide 80 after hydrolysis. 

Treatment of the sodium salts of 5-methyl(or-ethyl,-benzyl)-l,3-oxazine-4,6-dione 19 with l-fluoro-2,4,6-trimethylpyridinium triflate (Id) in tetrahydrofuran/hexamethylphosphoric triamide at — 78 °C gives the 5-fluoro derivatives 20 in high yield.58... 

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