1 -Phenylethan-1 -one

Bromo-l-phenylethan-l-one oxime 2 reacts with thiocyanates to give 2-thiocyana-toethan-l-one oximes 3 which, upon treatment with hydrazine hydrate or phenylhydrazine, furnish via the intermediate 4 the 2-hydrazino- or 5-phenyl-2-(phenylhydrazino)-6//-l,3,4-thia-diazines 6a, b.70 Compound 6a is also accessible from phcnacyl bromide and thiocarbohy-drazide.46 2-Bromo-1-phenylethan-1-one oxime reacts with thiourea to afford 5-phenyl-A//-1,3,4-thiadiazin-2-amine 5.70... 

C7H7NO3, 5-Methoxy-2-nitrosophenol (red form), 23, 658 CBH7CIN2O3, 0-Methyl-p-nitrobenzohydroximoyl chloride, 43B, 89 CBH7NO2, 2-Hydroximino-1-phenylethan-1-one, 44B, 56 CBHBBrNO, anti-a-Bromoacetophenone oxime, 39B, 42 CBH1BN2O2, Nitrosoisobutane trans-dimer, 26, 608... 

Reduction of T [l-(2-nitrophenyl)-l//-pyrrol-2-yl]sulfonyl -acetone or -1-phenylethan-l-one with sodium borohy-dride and 5% palladium on carbon, a reagent known to convert aromatic nitro compounds to hydroxylamines, triggers intramolecular interaction and gives pyrrolo[l,2- ][3,l,6]benzothiadiazocine derivatives 90 (Equation 11 <2001MI1405, 2004T8807>). This method was further successfully applied to the reductive cyclization of 2- [l-(2-nitrophenyl)-17/-pyrrol-2-yl]sulfanyl acetonitrile. 

Analysis of the vacuum volatile constituents of fresh tomatoes was carried out using capillary GLC-MS and packed column GLC separation with Infrared, NMR and CI-MS analysis. Evidence was obtained for the presence of the unusual components 3-damascenone, 1-nltro-2--phenylethane, 1-nltro-3-methylbutane, 3-cyclocltral and epoxy-3-1onone. A method for the quantitative analysis of the volatile aroma components In fresh tomato has been Improved and applied to fresh tomato samples. The quantitative data obtained have been combined with odor threshold data to calculate odor unit values (ratio of concentration / threshold) for 30 major tomato components. These calculations Indicate that the major contributors to fresh tomato aroma Include (Z)-3-hexenal, 3-lonone, hexanal, 3-damascenone, 1-penten-3-one, 3-methylbutanal, (E)-2-hexenal, 2-lso-butylthlazole, 1-nltrophenylethane and (E)-2-heptenal. 

Trimethylphenyl)ethan-l -one 1 -(4-Pyridyl)ethan-1 -one 1 -Fluoro-2-phenylethan-2-one (a -Fluoroacetophenone)... 

Methoxy-2-phenylethan-2-one 1 -Phenoxy-2-phenylethan-2-one 1 -Amino-2-phenylethan-2-one l-Pyrrolidinyl-2-phenylethan-2-one l-Dimethylamino-2-phenylethan-2-one l-Diphenylamino-2-phenylethan-2-one l-Phenylmethylsulfanyl-2-phenylethan-2-one l-Phenylsulfanyl-2-phenylethan-2-one l-Phenylselenyl-2-phenylethan-2-one 1 -Cyano-2-phenylethan-2-one 1 -Nitro-2-phenylethan-2-one l-Phenylsulfonyl-2-phenylethan-2-one... 

The ability of chiral bis(camphorquinone-a-dioximato)cobalt(Il) complexes (Section 1.2.1.2.4.2.6.3.1.) to catalyze carbene transfer from diazocarbonyl compounds (diazoacetic esters, 2-diazo-l-phenylethan-l-one) to terminal alkenes conjugated with vinyl, aryl, carbonyl, and cyano groups, has already been mentioned. The ee-values are 75-88 /o at best, often lower. The highest values are again obtained with bulky diazoacetic esters. The significance of these catalysts, however, is their ability to promote cyclopropanation of electron-deficient alkenes, such as acrylates and acrylonitriles, in contrast to the rhodium and copper catalysts discussed above. 

Methylene compounds with two neighboring sulfone groups can also be used for diazo transfer reactions as shown in 1964 by Klages and Bott. They obtained diazobis(ethylsulfonyl)methane (2.127) and diazobis[(diethylamino)sulfonyl)]me-thane (2.128) in aqueous ethanol and NaOH at - 5 °C and in ether with methyl-lithium at room temperature, respectively. In a similar way, methylene compounds activated by a sulfone and a carbonyl group, yield diazo derivatives, e.g., 1-diazo-l-(4 -toluene)sulfonyl propan-2-one (2.129, van Leusen et al., 1965), 2-diazo-2-(me-thylsulfonyl)-2-phenylethan-l-one (2.130, Illger et al., 1972), l-diazo-l-[(4 -nitro-phenyl)sulfonyl)]propan-2-one (2.131, Hodson et al., 1968), and other a-diazo-)ff-oxo-)ff -sulfonyl compounds (Monteiro, 1987 b) and similar diazoalkanes (van Leusen and Strating, 1988). 

In aqueous buffer solutions (pH 6), Bailes and Leveson (1970) observed, however, three polarographic waves in the reduction of 2-diazo-l-phenylethan-l-one (9.52). They correspond to the transfer of six, two, and two electrons, respectively, a result corroborated by controlled-potential coulometry by the same authors. These three waves are consistent with the mechanism (9-27), i. e., formation of a-aminoaceto-phenone (9.53), acetophenone (9.54), and 1-phenylethanol (9.55). Furthermore, polarography starting with the intermediates 9.53 and 9.54 gave results consistent with the waves for parts B and C of mechanism (9-27). 

One example is the polymerization of styrene using 1-ch loro-1-phenylethane as an initiator in the presence of Cu(I)(bpy) (bpy = bipyridine). Chlorine atom abstraction by the Cu(l) complex gives a radical that initiates polymerization. The chlorine atom can be transferred back to the chain at any time in an equilibrium process. This becomes particularly important when monomer runs low because the propagating radical is "capped" in this form. Addition of more monomer leads to further polymerization due to reaction again with radical generated from chlorine atom abstraction. 

Enolate 11 has also been employed in double asymmetric alkylations. Racemic 11 reacts with racemic 1-bromo-l-phenylethane (13) to produce a single diastereomeric alkylation product 1469. This result indicates that one enantiomer of 11 has selectively reacted with one enantiomer of the bromoalkane 13. probably via an SN2 mechanism. 

Application of Accelerating Rate Calorimetry (ARC) in Evaluating a Reaction with a Potentially Explosive Nitro Compound. One of our process development projects required the preparation of 2-hydroxy-l-nitro-2-phenylethane via the addition of sodium methoxide to a mixture of one mole of benzaldehyde and one mole of nitromethane in methanol (Scheme 1). 

One-electron oxidation of an olefin, arene, or a bibenzyl group can lead to C—H or C—C bond cleavage to produce an allyl or benzyl radical [40, 41]. This area has been pioneered by Arnold [41], The PET reaction of 1,1,2,2-tetraphenylethane and methyl-3,3-diphenylethyl ether have been reported by Arnold and coworkers [41] to provide heterolytic C—C bond cleavage through an intermediate tetra-phenylethane cation-radical. The cation-radical intermediate fragments to di-phenylmethyl radical and diphenylmethyl carbocation. 

Nitro-2-phenylethane bears a similar relationship to phenylalanine and phenylacetonitrile. The nitro compounds are possibly formed by oxidation of these amino acids. Stone et al., ( ) had previously presented evidence (using radioactive isotopes) that leucine was one of the precursors of 2-isobutylthiazole. 1-Nitro-2-phenylethane is a moderately potent odorant with an odor threshold of 2 ppb and as later discussed probably contributes to the tomato aroma. 

One phenyl substituted 1,2-diol has been studied in detail, viz. phenylethane-... 

The reaction of 1-chloromagnesio-l-phenylethane with benzophenone was the only one among the reactions investigated (nine carbonyl compounds were used) that gave a reasonable yield of the normal product 55%. Of the benzophenone, 36% could be recovered from the reaction mixture. None of the products D or T were detected. Therefore, it is... 

An alkylbenzene with a side chain more complicated than methyl offers more than one position for attack, and so we must consider the likelihood of obtaining a mixture of isomers. Bromination of ethylbenzene, for example, could theoretically yield two products 1-bromo-l-phenylethane and 2-bromo-l-phenylethane. Despite... 

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