P-Phenylethyl bromide

P-Phenylethylamine. Prepare p-phenylethyl phthalimide as above by substituting P phenylethyl bromide (Section 111,37) for benzyl... 

Out of the above the P elimination is most common. These eliminations result in the formation of alkenes and alkynes. When P phenylethyl bromide is heated with an alcoholic solution of an alkali first a carbanion is formed by the loss of a proton followed by the loss of a halide ion and simultaneous formation of a double bond. 

P-Phenylethyl alcohol, 812,816 Phenylethylene, 1015,1024 a-Phenylethylamine, 560, 566 P-Phenylethy,amine, 560, 567,569 Phenylethylbarbituric acid, 1003,1005 P-Phenylethyl bromide, 283 P-Phenylethyl iodide, 288 Phenylglycine-o-carboxylic acid, 980 Phenylglyoxal, 866 Phenylhydrazine, 635, 636 hydrochloride, 636, 637 Phenylhydrazine acetate reagent, 343, 721 ... 

Cognate preparation. 2-Phenylethylamine. Prepare 2-phenylethylphthali-mide as above by substituting 2-phenylethyl bromide (Expt 5.55) for benzyl chloride recrystallise the crude product from glacial acetic acid m.p. 131— 132°C. Convert it into 2-phenylethylamine by treatment with hydrazine hydrate and hydrochloric acid as described for benzylamine. The yield of 2-phenylethylamine, b.p. 200-205 °C, is about 95 per cent. 

In cases where the more established kinetic approaches become insensitive, mixed solvent studies on rate of elimination may prove enlightening. Although p and knlko remain unchanged in the elimination of 2-arylethyl bromides with t-butoxide in t-butyl alcohol on the addition of dimethyl sulphoxide (0-2.23 M), a rate increase of 120 times is noted" . Smaller increases in rate are observed for similar variations in the concentration of added dipolar aprotic solvent in elimination from 1-phenylethyl bromide and 9-bromo-9,9 -bifluorenyP , but a steeper rise in rate is observed for 2,2-diphenylethyl tosylate. A cor-... 

The white needle-shaped 1 -/3-phenylethylcyclohexanol-1 was prepared from phenylethyl bromide and cyclohexanone, which was crystallized by making a saturated solution in warm petroleum ether and chilling it with an ice salt or solid carbon dioxide-alcohol mixture. The yield was 54%, m.p. 57°C, b.p. 145°C at 2-3 mmHg. 

Solid 2-isopropyl-1,3-benzodithiole 1,1,3,3-tetroxide added to a suspension of NaH in THF, treated with 2-phenylethyl bromide when H2 evolution had ceased, and heated at 80° for 24h - intermediate (Y 75%), in methanol at 50° treated in 3 portions over 3 h with Mg-turnings, and worked up after ca. 4 h - 4-methylpentyl-benzene (Y 72%). This is part of a multistep synthesis of hydrocarbons from two halide molecules with insertion of a methylene group. F.e., also 1,1-disulfonylcyclo-pentanes from 1,4-diiodides, s. E.P. Kundig, A.F. Cunningham, Jr., Tetrahedron 44, 6855-60 (1988). 

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