P-Phenyl ethyl alcohol

Definition From acetaldehyde with a mixture of propyl and p-phenyl ethyl alcohols Empirical C13H20O2... 

Benzyl ciimamate, iso-butyl alcohol, iso-amyl alcohol, furfural, methyl eugenol, iso-asarone, P-phenyl ethyl alcohol, trans-linalool oxide, elemicine... 

Cinnamic Alcohol.—The latter alcohol yields an unsaturated aromatic acid known as cinnamic acid (p. 697), and the alcohol is thus known as cinnamic alcohol. Phenyl ethyl alcohol, CeHs—CH2—CH2 —OH, is a constituent of oil of rose and has the characteristic odor of roses. 

In a similar manner the other amino acids react tyrosine, j3-p-hydroxy-phenyl-a-amino-butyric acid yielding p-hydroxy-phenyl-ethyl alcohol, tyrosol while phenyl-alanine, a-amino-j8-phenyl-propionic acid, yields phenyl-ethyl alcohol. Succinic acid, for example, which is of usual occurrence in fermented liquors is probably formed by a similar reaction from glutamic acid with the additional step of oxidation in the process. 

Hydrogenation of p-i obutyl acetophenone to p-isobutyl phenyl ethyl alcohol Pd/AljOj or Ni/AljOj Ibuprofen MASR or JLSR... 

NAME P i-Phenyl ethyl alcohol STRUCTURAL FORMULA... 

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).

In Eq. (8.75), Z is the adsorption site on palladium on alumina catalyst. On this site, acetophenone (A) is adsorbed and hydrogenated to J4-l-phenyl ethyl alcohol (B) and to S-1-phenyl ethyl alcohol (C). This is followed by acylation of B to J4-1-phenyl ethyl acetate (P) over an immobihsed Hpase. First the acyl donor, ethyl acetate (Q), is bound with the free enzyme (E) forming a noncovalent enzyme-acyl complex (EQ), releasing ethanol (I). The substrate in the acylation step, J4-1-phenyl ethyl alcohol (B), is thereafter combined with EQ, which subsequendy relinquished J4-phenyl ethyl acetate (P) and E. Styrene (S) is obtained by dehydration of B and C over Pd/AI2O3. The side product ethyl benzene (F) is formed as a result of fast hydrogenation of S (step 7 ) and de-acylation of P in the presence of H2 releasing acetic acid (AcOH) to the media. 

In these kinetic equations, [A], [B], [C], [P], [F] are the concentrations of, respectively, acetophenone, R-1-phenyl ethyl alcohol, S-1-phenyl ethyl alcohol, i -1-phenyl ethyl acetate, and ethyl benzene Ka, Kb, Kq, Kp, Kp are the adsorption constants for acetophenone, i -1-phenyl ethyl alcohol, S-1-phenyl ethyl alcohol, ethyl benzene, R-1-phenyl ethyl acetate on the solid catalyst, fe reaction rate constants of a particular step (fei and fe2 contain also hydrogen pressure dependence), f the rates of reactions. Qat and Cenzyme are the concentrations of the metal catalyst and the immobilised enzyme, respectively. Since heterogeneous catalysts deactivated in the presence of enzyme the generation rates for each compound should include the activity function (Jjeact ... 

In a 1 litre round-bottomed flask provided with an efficient double surface condenser, place 40 g. (39 ml.) of aniline, 50 g. (40 ml.) of carbon sulphide CAUTION inflammable) (1), and 50 g. (63-5 ml.) of absolute ethyl alcohol (2). Set up the apparatus in the fume cupboard or attach an absorption device to the top of the condenser (see Fig. 11, 8, 1) to absorb the hydrogen sulphide which is evolved. Heat upon an electrically-heated water bath or upon a steam bath for 8 hours or until the contents of the flask sohdify. When the reaction is complete, arrange the condenser for downward distillation (Fig. 11, 13, 3), and remove the excess of carbon disulphide and alcohol (CA UTION inflammable there must be no flame near the receiver). Shake the residue in the flask with excess of dilute hydrochloric acid (1 10) to remove any aniline present, filter at the pump, wash with water, and drain well. Dry in the steam oven. The yield of crude product, which is quite satisfactory for the preparation of phenyl iao-thiocyanute (Section IV.95), is 40-45 g. Recrystalhse the crude thiocarbanihde by dissolving it, under reflux, in boiling rectified spirit (filter through a hot water funnel if the solution is not clear), and add hot water until the solution just becomes cloudy and allow to cool. Pure sj/m.-diphenylthiourea separates in colourless needles, m.p, 154°,... 

The N-[)3-(p-aminophenyl)ethyl]-4-phenyl-4-carboethoxypiperidine is dissolved in 50 cc of hot anhydrous ethanol, an excess (about 20 cc) of 20% alcoholic hydrochloric acid solution is added upon scratching the side of the container crystals form. One hundred cubic centimeters of ether are then added to the mixture, the ethereal mixture is cooled, and the crystalline material which precipitates is recovered by filtration, washed with ether, and dried to give 12.7 grams of N-[)3-(p-aminophenyl)ethyl]-4-phenyl-4-carboethoxypiperidine dihydrochloride which can be further purified by recrystallization from ethanol or methanol to give substantially pure material MP 275°-277°C. 

These are taken up in 250 cc of 2 N caustic soda solution and heated for 1 hour on a boiling water bath. With hydrochloric acid, the pH is then adjusted to 6 to 7 and the precipitate is filtered with suction and crystallized from 75% ethyl alcohol. The resulting 3-(p-aminobenzene sulfonamido)-2-phenyl-pvrazole crystallizes in white crystals and has a melting point of 177° to 178°C. 

When ethyl acetoacetate is warmed with an equivalent quantity of phenyl-hydrazine, the compound (I), which is not a true hydrazone, is first formed this undergoes ring formation (II) with loss of ethyl alcohol upon further heating. The product (II) is N or l-phenyl-3-methyl-5-p)U azolone. 

The product is 2-phenyl-2-(l-hydroxycyclopentyl)ethanoic acid, melting at 95° to 97°C. Of this product, 4.5 g in 30 cc of dry isopropyl alcohol are refluxed for 16 hours with 2.5 g of p-chloroethyl dimethyl amine. The solution is cooled and filtered clear from the solid by-product. The solvent is removed under reduced pressure on the steam bath and the residue is washed with anhydrous ether. It is dissolved in ethyl acetate from which it crystallizes. It is the hydrochloride of p-(dimethylamino)ethyl ester of 2-phenyl-2-(l-hydroxycyclopentyl) ethanoic acid, melting at 134° to 136°C. 

N-(Phenyl-p-arsinic acid)-glycinediethylamlde foniis microscopic aggregates of short needles, darkening above 195° C., and melting at 199° to 201° C. with gas evolution. It is sparingly soluble in boiling water, but soluble in boiling methyl alcohol or 50 per cent, ethyl alcohol. 

L-Phenylalanine,which is derived via the shikimic acid pathway,is an important precursor for aromatic aroma components. This amino acid can be transformed into phe-nylpyruvate by transamination and by subsequent decarboxylation to 2-phenylacetyl-CoA in an analogous reaction as discussed for leucine and valine. 2-Phenylacetyl-CoA is converted into esters of a variety of alcohols or reduced to 2-phenylethanol and transformed into 2-phenyl-ethyl esters. The end products of phenylalanine catabolism are fumaric acid and acetoacetate which are further metabolized by the TCA-cycle. Phenylalanine ammonia lyase converts the amino acid into cinnamic acid, the key intermediate of phenylpropanoid metabolism. By a series of enzymes (cinnamate-4-hydroxylase, p-coumarate 3-hydroxylase, catechol O-methyltransferase and ferulate 5-hydroxylase) cinnamic acid is transformed into p-couma-ric-, caffeic-, ferulic-, 5-hydroxyferulic- and sinapic acids,which act as precursors for flavor components and are important intermediates in the biosynthesis of fla-vonoides, lignins, etc. Reduction of cinnamic acids to aldehydes and alcohols by cinnamoyl-CoA NADPH-oxido-reductase and cinnamoyl-alcohol-dehydrogenase form important flavor compounds such as cinnamic aldehyde, cin-namyl alcohol and esters. Further reduction of cinnamyl alcohols lead to propenyl- and allylphenols such as... 

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