Phenylethanol phenylethyl alcohol

Phenylethanol (phenylethyl alcohol 2-phenylethanol). Typical in-use concentration 0.25-0.5%. It is reported to have greater activity against Gram-negative organisms and is usually employed in conjunction with another agent. 

Phenethyl alcohol p-Phenethyl alcohol 2-Phenylethanol p-Phenylethanol Phenylethyl alcohol... 

Fig. 4. Mass spectrum of the peak with the retention time of 10.72 min. From the NIST library search, the compoimd was matched with 2-phenylethanol (phenylethyl alcohol) with 932 similar index (SI).

CL-Phenylethanol (a-Phenylethyl alcohol, Methyl-phenyl carbinol). C6H5, CHOH.CH3, mw 122.16, liq, bp 203.6° at 475mm, d 1.019g/cc at 13/4°. Prepn and other properties are given in Beil 6,475, (236) [445]... 

Benzeneethanol benzyl carbinol benzylmethanol p-hydroxy-ethyl benzene PEA phenethanol p-phenylethyl alcohol 2-phenylethyl alcohol phenylethanol. 

Beilstein Handbook Reference) AI3-00744 Benzeneethanol Benzylcarbinol Benzyi-methanol BRN 1905732 Caswell No. 655C EINECS 200-466-2 EPA Pesticide Chemical Code 001503 Ethanol, 2-phenyl- FEMA No. 2858 FEMA Number 2858 p-Fenethylalkohol P-Fenylethanol HSDB 5002 p-Hydroxyethylbenzene Methanol, benzyl- NSC 406252 PEA Phenethanol p-Phenylethanol Phenethyl alcohol Phenylethyl alcohol. Has the smell of roses. Used In perfumery and as an antimicrobial agent. Clear liquid mp= -27° bp760 = 219-221° dS = 1.017 n6 = 1.530 soluble in H2O (2 g/100 ml), mote soluble in organic solvents LDso (rat orl)= 1790 mg/kg. Lancaster Synthesis Co. Sigma-Aldrich Fine Chem. 

Synonyms cas 6O-12-8 phenylethyl alcohol 2-phenylethanol benzyl carbinol... 

Methyl benzyl alcohol. SeeCresyl alcohol o-Methylbenzyl alcohol CAS 98-85-1 EINECS/ELINCS 202-707-1 UN 2937 (DOT) FEMA 2685 Synonyms Benzenemethanol, a-methyl- Ethanol, 1-phenyl- Methyl phenylcarbinol Methylphenylmethanol a-Phenethyl alcohol s-Phenethyl alcohol 1-Phenylethanol a-Phenylethyl alcohol Phenylmethylcarbinol Styrallyl alcohol Styralyl alcohol Empirical CsHioO Formula C6H5CH(CH3)OH Properties Colorless liq. mild floral odor sol. in alcohol, glycerol, min. oil, oxygenated and hydrocarbon soivs. si. sol. in water m.w. 122.17 dens. 1.009-1.014 vapor pressure 0.1 mm (20 C) ... 

Besides ethanol, higher alcohols (also known as fusel alcohols or fusel oils) are the major alcohols that impart sensory properties to beer, including n-propanol, isobutanol, active amyl alcohol, isoamyl alcohol and 2-phenylethyl alcohol (2-phenylethanol)... 

Williams employed complexes of Al, Rh, or Ir in combination with Pseudomonas Jluorescens lipase (PFL) for the DKR of 1-phenylethanol. The best results were obtained using Rh2(OAc)4 as the catalyst for the racemization, and 60% conversion of the alcohol to give 1-phenylethyl acetate in 98% ee was obtained (Figure 4.6) [19]. At higher conversion, the enantiomeric excess dropped and 76% conversion gave 80% ee. 

The one-pot dynamic kinetic resolution (DKR) of ( )-l-phenylethanol lipase esterification in the presence of zeolite beta followed by saponification leads to (R)-l phenylethanol in 70 % isolated yield at a multi-gram scale. The DKR consists of two parallel reactions kinetic resolution by transesterification with an immobilized biocatalyst (lipase B from Candida antarctica) and in situ racemization over a zeolite beta (Si/Al = 150). With vinyl octanoate as the acyl donor, the desired ester of (R)-l-phenylethanol was obtained with a yield of 80 % and an ee of 98 %. The chiral secondary alcohol can be regenerated from the ester without loss of optical purity. The advantages of this method are that it uses a single liquid phase and both catalysts are solids which can be easily removed by filtration. This makes the method suitable for scale-up. The examples given here describe the multi-gram synthesis of (R)-l-phenylethyl octanoate and the hydrolysis of the ester to obtain pure (R)-l-phenylethanol. 

The first use of a metal catalyst in the DKR of secondary alcohols was reported by Williams et al. [7]. In this work, various rhodium, iridium, ruthenium and aluminum complexes were tested. Among them, only Rh2(OAc)4 and [Rh(cod)Cl]2 showed reasonable activity as the racemization catalyst in the DKR of 1-phenylethanol. The racemization occurred through transfer-hydrogenation reactions and required stoichiometric amounts of ketone as hydrogen acceptor. The DKR of 1-phenylethanol performed with Rh2(OAc)4 and Pseudomonas Jluore-scens lipase gave (R)-l-phenylethyl acetate of 98%e.e. at 60% conversion after 72 h. 

We synthesized 8 by the one-step reaction of [Ph4(Tl -C4CO)]Ru(CO)3 with benzyl chloride. In contrast to previous alcohol racemization catalysts, 8 was stable in the air during racemization [30]. The racemization was performed even under 1 atm of molecular oxygen. Thus, alcohol DKR was for the first time possible with 8 in the air at room temperature (R)-l-phenylethyl acetate (99% yield, greater than 99%e.e.) was obtained from 1-phenylethanol by using 4mol% of 8, CALB and isopropenyl acetate in the presence of potassium phosphate (Scheme 1.22). This catalyst system was effective for both benzylic and aliphatic alcohols. The synthetic method for 8 was applied to the preparation of a polymer-bound derivative (9). Hydroxymethyl polystyrene was reacted with 4-(chloromethyl)benzoyl chloride to... 

In this research the kinetic resolution of 1-phenylethanol catalyzed by commercially available immobilized lipase from CALB was assayed in non-aqueous conditions in SC-CO2 and IL/SC-CO2 systems with the aim of studying the enan-tioselectivity of Novozym 435. The influence of different reaction parameters, such as pressure, the acyl donor/alcohol molar ratio and different ILs, on the enantio-merically pure compound (R)-l-phenylethyl acetate formation via kinetic resolution of 1-phenylethanol was investigated. 

For a reversible reaction an increase in the acyl donor concentration results in higher product yields. In this case the chemical equilibrium is shifted towards synthesis. On the other hand, high concentrations of substrates may cause inhibition and the reaction is slowed down. For (R)-l-phenylethyl acetate formation the effect of the substrate vinyl acetate/l-phenylethanol molar ratio on the final conversion was studied. The results are presented on Figure 8.3. A higher yield of the enantiopure compound was achieved when raising the acyl donor molar concentration with respect to the alcohol concentration. A conversion of 49.9% was obtained at an acyl donor/alcohol molar ratio of 9/1. After 5 h of reaction at tested conditions a complete conversion of (R)-l-phenylethanol into the enantiopure (R)-l-phenylethyl acetate was attained. The enantiomeric excess for reactants (eeR) was 99.9%. 

Synthesis of optically active alcohols.1 For asymmetric synthesis of alcohols, the carbanion salt (2) is generated from optically active (R)-methyl p-tolyl sulfoxide (I).2 The optically active carbanion reacts with benzaldehyde (3) to give a 1 1 diastereomeric mixture of 2-hydroxy-2-phenylethyl p-tolyl sulfoxides (4a) and (4b) in 84% yield-These can be separated by silica gel chromatography and fractional crystallizations to give (4a, oq, + 91.7°, 17% yield) and (4b, aD + 202.8°, 15.5% yield). Raney nickel desulfurization of (4a) and (4b) gives (SH-)-l-phenylethanol (5a, aD — 42.6°) and R-(+)-l-phenylethanol (5b, aD +42.1°), respectively, in about 60% yield. Since the specific rotation of optically pure (5b) is aD +43.5°, alcohols of high optical purity can be obtained in this way. 

The acrylate- and methacrylate-derivatized r 5-(benzene)tricarbonylchromium monomers 20 65,66,68,72 21,69>72 and 2273 (Scheme 1.2) were synthesized from benzyl alcohol or 2-phenylethanol when reacted with Cr(CO)6. The alcohols were esterified with either acrylyl or methacrylyl chloride in ether/pyridine and purified by multiple recrystallizations from CS2. Homopolymerizations proceeded in classic fashion with no special electronic effects from the rr-complexed Cr(CO)3 moiety.65,73 Acrylate 20 was copolymerized with styrene and methyl methacrylate and the reactivity ratios were obtained.65 Acrylate 21 and methacrylate, 22, copolymerized readily with styrene, methyl acrylate, acrylonitrile, and 2-phenylethyl acrylate to give bimodal molecular-weight distributions using AIBN initiation.69 Copolymerization of 20 with ferrocenylmethyl acrylate, 2, generates copolymers with varying mole ratios of two transition metals, Cr and Fe (see structure 34).65... 

The main volatiles in wines are the higher aliphatic alcohols, ethyl esters, and acetates formed from yeasts during fermentation. Acetates are very important flavors characterized by fruity notes, C4-Ci0 fatty acid ethyl esters manly confer fruity scents to the wine. Other wine aroma compounds are C6 alcohols, such as 1-hexanol and cis- and trans-3-hexen-l-ol, 2-phenylethanol, and 2-phenylethyl acetate. Contents of these compounds in wine are linked to the winemaking processes used fermentation temperature, yeast strain type, nitrogen level in must available for yeasts during fermentation, clarification of wine (Rapp and Versini, 1991). Much literature on the wine aroma compounds was reported in reviews by Schreier (1979) and Rapp (1988). 

Figure 5.1. HS (headspace)-SPME-GC/MS chromatogram recorded in the analysis of a Gewiirztraminer wine volatiles performed using a CAR-PDMS-DVB fiber and the experimental conditions reported in Table 5.1. (1) ethyl hexanoate (2) 2- and 3-methyl-1-butanol (isoamyl alcohols) (3) ethyl lactate (4) 1-hexanol (5) ethyl octanoate (6) 1-heptanol (internal standard) (7) benzaldehyde (8) linalool (9) ethyl decanoate (10) diethyl succinate (11) a-terpineol (12) 2-phenylethyl acetate (13) 2-phenylethanol (14) octanoic acid.

Fishbein and coworkers (Finneman et al., 1993) also investigated kinetics and products of the dediazoniation of two slightly more complex diazenolates, (E )-l-methyl-propyl- and (E )-l-phenylethyldiazenolate in aqueous buffer (pH 6-12). Here, the side equilibria of A-protonation and of C-deprotonation cannot be detected analytically or kinetically. The products are the unrearranged alcohols (53 2-butanol and 99.1 1-phenylethanol, respectively) and alkenes (7 but-l-ene -h 32 0 but-2-ene, and 0.9 styrene, respectively). The kinetics are compatible with pATa values of the (E )-diazenols 7.19 (R = 1-methylpropyl 8.83, 1-phenylethyl 8.32) and the mechanism (7-5). ... 

The conversion of alcohols to chlorides with phosphorus oxychloride can be similarly described. It is noteworhy that 1-phenylethanol is converted to 1-phenylethyl chloride with 85% inversion of configuration with phosphorus oxychloride in pyridine. 

Acid zeolites have also been tested for the racemisation of alcohols under biphasic conditions.Their scope was found, however, to be limited to benzylic alcohols, since electron-rich benzylic alcohols were not suitable substrates because of the formation of dimers. Under optimised conditions, based on the use of H-Beta zeolite, CALB lipase, and an excess of vinyl octanoate at 60 °C, enantiopure (R)-l-phenylethyl octanoate (>99% ee) was obtained in 90% yield from 1-phenylethanol. In addition, Lozano et al. have recently performed the DKR of this alcohol in the presence of acidic zeolite catalysts (CBV400) in an ionic liquid-supercritical carbon dioxide system with a continuous reaction system. Therefore, when Novozym 435 was employed at 50 °C and 100 bars in the presence of vinylpropanoate as the acyl donor, the expected (R)-phenylethylpropionate was produced in excellent yield of 98% with enantioselectivity of 97% ee and without any activity loss during 14 days of operation. 

---