A-Phenyl Ethyl Acetate

FEMA No. 2684 a-Phenyl Ethyl Acetate f>CHCH3 ococh3 gardenia giy ins—water/ 214° mL 60% ale... 

The effects of a- and 8-phenyl substitution can be calculated from the data of Table 5. The reaction rates for ethyl acetate a-phenyl ethyl-acetate a, /3-diphenylethylacetate are 1 45 130. Thus a phenyl group in the a-position, has a relatively large effect in the /3-position, a much smaller one. This behaviour is also observed with the halides, although in that case the enhancement of rate on a-phenylation is very much larger. 

Phenyl-ethyl Acetate.—Phenyl-ethyl alcohol yields a series of highly aromatic esters. That of acetic acid has the formula... 

A typical example that illustrates the method concerns the lipase- or esterase-catalyzed hydrolytic kinetic resolution of rac-1-phenyl ethyl acetate, derived from rac-1-phenyl ethanol (20). However, the acetate of any chiral alcohol or the acetamide of any chiral amine can be used. A 1 1 mixture of labeled and non-labeled compounds (S)- C-19 and (f )-19 is prepared, which simulates a racemate. It is used in the actual catalytic hydrolytic kinetic resolution, which affords a mixture of true enantiomers (5)-20 and (J )-20 as well as labeled and non-labeled acetic acid C-21 and 21, respectively, together with non-reacted starting esters 19. At 50% conversion (or at any other point of the kinetic resolution), the ratio of (5)- C-19 to (1 )-19 correlates with the enantiomeric purity of the non-reacted ester, and the ratio of C-21 to 21 reveals the relative amounts of (5)-20 and (J )-20 (98). 

Fig. 2 Variation of resolution with flow for benzyl alcohol and phenyl ethanol in a heptane-ethyl acetate-methanol-water (1.4 0.1 0.5 1.0) phase system.

As described by Lambrechts and Pretorius (2000) and Verstrepen et al. (2003), esters possess a range of odors such as solvent-hke or nail polish (ethyl acetate), fruity, pear, or banana (isoamyl acetate), floral or fruity (ethyl butanoate), sour apple (ethyl caproate and ethyl caprylate), and flowery, roses, or honey (phenyl ethyl acetate). Given the number of different esters present in varying concentrations produced by yeasts, there is little doubt that wine aroma can be strongly influenced by these compounds (Schreier, 1979). 

The polymerization of optically active acetals and vinyl acrylamides has been described but only in a few cases. Poly-[(-)-7V-propyl-7V-phenylethyl-acrylamide] and poly-[(+)-A -methyl-A -phenyl-ethyl-acrylamide] (VIII) of different tacticity were prepared by Schultz and Kaiser [18] from the corresponding monomers using radical or ionic initiators. No assumptions on polymer conformation in solution have been made. 

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).

Acyl-enzyme complexes are crucial intermediates in all lipase catalyzed reactions and thus the lipases first form an acyl-enzyme complex with the acyl donor. Eq. (8.75) displays a sequential two-step mechanism for enzymatic kinetic resolution of J4-l-phenyl ethyl alcohol to i4-l-phenyl ethyl acetate (route N ). 

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 ... 

It is obtained by allowing a solution of one molecule of phenol-acetic -ester in three to four times its weight of absolute alcohol, to fall in drops on a quantity of sodium calculated for six atoms. It is then heated for several hours on an oil-bath, until the sodium has disappeared, if necessary adding more alcohol. After cooling, water is added, and the ester which is not attacked is saponified. The alcohol and phenyl-ethyl alcohol are then distilled off with steam, when the latter is at once obtained in the pure state. 

It is suitable, not only for rose odours, but also for blending with almost any flower oil. Phenyl-ethyl alcohol forms a solid compound with chloride of calcium, which is very useful for its purification. On oxidation it is converted into a mixture of phenyl-acetaldehyde and phenyl-acetic acid. The last-named body forms an ethyl ester melting at 28°, which serves for its identification. 

Phenyl-propyl alcohol, CgH. CHj. CH.2. CHj. OH, is the next highest homologue of phenyl-ethyl alcohol, and is also known as hydro-cinnamyl alcohol. Like the last described bodies it has been known for many years, its first preparation being described in the Aivnalen (188, 202). It occurs as a cinnamic acid ester in storax, and as an acetic ester in cassia oil. It is prepared synthetically by the reduction of cinnamyl alcohol with sodium amalgam and water, or by the reduction of cinnamic or benzyl acetic esters with sodium and absolute alcohol. It has the following characters —... 

Styrolyl Acetate.—Styrolene alcohol, or phenyl-ethyl glycol, is an alcohol prepared from styrolene dibromide by the action of caustic potash. It can be esterified, and forms an acetic ester of the formula CgHj. CH(OH)CHg. OOC. CHg. It is an ester with a fine flower odour, which has been described as fragrant and dreamy . It is generally stated by those who have used it that it is indispensable in the preparation of fine flower bouquets with a jasmin odour. 

Chloro-1 -methyl-5-phenyl-s-trizolo[4,3-a]quinoline A stirred mixture of 6triethyl-orthoacetate (0.925 g,0.0057 mol) and xylene (100 ml) was refluxed, under nitrogen, for 2 hours 40 minutes. During this period the ethanol formed in the reaction was removed by distillation through a short,glass helix-packed column. The mixture was concentrated to dryness In vacuo and the residue was crystallized from methanol-ethyl acetate to give 1.28 g of 7-chloro-1-methyl-5-phenyl-s-triazolo[4,3-a]-quinoline (83.9% yield). The analytical sample was crystallized from methylene chloride methanol and had a melting point 252.5°-253.5°C. 

When the reduction is completed, the 1-phenyl-2-aminopropane may be separated from the solution. A convenient way of doing this is by removing the ethanol and ethyl acetate present by evaporation and then making the residual solution strongly alkaline by addition of caustic alkali. The basic layer thus formed is separated from the aqueous solution and contains the desired 1-phenyl-2-amlnopropane. 

The benzene was distilled from the extract and the residue of d-N-methyl-N-benzyl-)3-phenyl-isopropylamine was distilled at reduced pressure. The thus obtained free base, distilling at 127°C at a pressure of 0.2 mm of mercury and having an np of 1.5515, was dissolved in ethyl acetate and a molar equivalent of ethanolic hydrogen chloride was added thereto. Anhydrous ether was added to the mixture and d-N-methyl-N-benzyl-)3-phenylisopropyl-amine hydrochloride precipitated from the reaction mixture as an oil which was crystallized from ethyl acetate to give crystals melting at 129° to 130°C. 

A suspension of 45 g 3-phenoxycarbonyloxy-1 -methyl-7-chloro-5-pheny -1,3-dihydro-2H-1,4-benzodiazepin-2-one in 450 ml methanol is treated with stirring, with 43 ml of a solution of dimethylamine in methanol (containlng31 gdimethylamine in 100 ml). Stirring ismaintained at 20°C to 25°C during 5 hours. The reaction mixture is filtered, and the filtrate is diluted with 450 ml water. The precipitate thus formed, is 3-(N,N-dimethylcarbamoyloxy)-1-methy -7-chloro-5-phenyl-1,3-dihydro-2H-1,4-benzodiazepin-2-one, which is collected on a filter, dried and recrystallized from ethyl acetate, and has a melting point of 173°C to 174°C. 

The filtrate is treated with excess hydrochloric acid and evaporated to obtain a pale yellow oil. Five grams of the oil thus obtained is treated with 15 cc of saturated potassium carbonate solution and the mixture extracted with 50 cc of ether, then with 30 cc of ethyl acetate and finally with two 30 cc portions of ethanol. Evaporation of the solvent from the extract gives the following quantities of the desired 1-phenyl-2-aminopropane-1,3-diol 0.5 g, 1.0 g and 3.1 g. 

Two hundred milligrams of the diacetate of (dl)-reg.-1-phenyl-2-dichloroacetamidopropane-1,3-dioi is added to a mixture consisting of 0.25 cc of concentrated nitric acid and 0.25 cc of concentrated sulfuric acid at 0°C. The reaction mixture is stirred until solution is complete, poured onto 25 g of ice and the mixture extracted with ethyl acetate. The ethyl acetate extracts are evaporated under reduced pressure and the diacetate of (dl)-reg.-l-p-nitrophenyl-2-dichloroacetamidopropane-1,3-diol so produced purified by recrystallization from ethanol MP 134°C. 

A mixture of 20 g of 1. [p.((3.diethylaminoethoxy)phenyl]-1,2-diphenylethanol in 200 cc of ethanol containing an excess of hydrogen chloride was refluxed 3 hours. The solvent and excess hydrogen chloride were removed under vacuum, and the residue was dissolved in a mixture of ethyl acetate and methylene chloride. 1-[p-((3.diethylaminoethoxv)phenyl] -1,2-diphenylethylene hydrochloride was obtained, melting at 148° to 157°C. This hydrochloride salt was treated with N-chlorosuccinimide in dry chloroform under reflux. The product then obtained was converted to the free base and treated with citric acid. The dihydrogen citrate salt of 1-[p-((3-diethylaminoethoxy)phenyl]-1,2-diphenylchloroethylene was obtained, melting at 116.5° to 118°C. 

The crude product obtained above is dried in high vacuum and then dissolved in 4 cc of pyridine. About 3 cc of acetic anhydride is added. The mixture is then heated on the steam bath for about 15 minutes and then evaporated to dryness in vacuo. About 20 cc of water is added. The product is then extracted into 150 cc of ethyl acetate, washed with saturated sodium bicarbonate solution and water, and dried over sodium sulfate. The solvent is removed in vacuo to give a residue which is crystallized from ethyl acetate-benzene to yield about 250 mg of 11/3,17a,21-trihydroxy-6,16a-dimethyl-20-oxo-2 -phenyl-4,6-pregnadieno-[3,2-c] pyrazole 21-aCetate, as described in U.S. Patent 3,300,483. 

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