2-Benzyl-2- butanone

How would you prepare l-phenyl-2-butanone, Q5H5CH2COCH2CH3, from benzyl bromide, C6HsCH2Br More than one step is required. 

The acetone-sensitized photodehydrochlorination of 1,4-dichlorobutane is not suppressed by triplet quenchers (20), but the fluorescence of the sensitizer is quenched by the alkyl chloride (13). These observations imply the operation of a mechanism involving collisional deactivation, by the substrate, of the acetone excited singlet state (13,21). This type of mechanism has received strong support from another study in which the fluorescence of acetone and 2-butanone was found to be quenched by several alkyl and benzyl chlorides (24). The detailed mechanism for alkanone sensitization proposed on the basis of the latter work invokes a charge-transfer (singlet ketone)-substrate exciplex (24) and is similar to one of the mechanisms that has been suggested (15) for sensitization by ketone triplets (cf. Equations 4 and 5). 

Comparable effects were observed in the catalysis of the dehydrofluorination of 4-fluoro-4-(p-nitrophenyl)-2-butanone using Mi-polymers or even Ml-pro-teins (see later) imprinted with suitable TSA templates. Focusing on the two sp3 hybridized carbons (C2 and C3) of the butanone which are converted to sp2 carbons as a result of dehydrofluorination, the search for the right TSA led to N-benzyl-AT-isopropylamine (Fig. 13) either containing a nitro-group [62] at the aromatic ring or not [63,64]. 

Ammonium perchlorate, Impurities, 4004 Azidoacetic acid, 0774 f Aziridine, Acids, 0863 Benzoyl azide, 2698 Benzyl chloroformate, 2931 1,2-Bis(dilluoroamino)-A-nitroethylamine, 0803 Bromine trioxide, 0259 2-Butanone oxime, 1654 2-Butyne-l,4-diol, 1526... 

An extension of the above preparative method of chirality transfer is the preparation of dioxolanes 16 from lactic acid and 3,3-dimelhyl-2-butanone (pinacolone)80. In this case the crude cis/trans ratio is already 95 5, thus, it is much better than the observed 80 20 ratio observed with trimethylacetaldehyde. Alkylation of 16 with benzyl bromide seems to proceed with a satisfactory 95 5 selectivity. 

Preparation of 2-benzyl-l-[4-(2-hydroxyethylamino)phenyl]-2-dimethyl-amino-1 -butanone... 

A reactor charged with 2-benzyl-l-(4-fluorophenyl)-2-dimethylamino-l-butanone (0.15 mol) and ethanolamine (1.05 mol) were dissolved in 400 ml dimethylacetamide and then treated with potassium carbonate (0.3 mol) and then heated to 140°C for 16 hours, cooled, and diluted with water. The aqueous phase was extracted several times with ethyl acetate and combined extracts washed with water and dried using magnesium sulfate. The mixture was then concentrated and the residue isolated as a yellowish-brown oil. It was purified using chromatography on silica gel with petroleum ether/ethyl acetate 2 1 to 1 1, respectively. The product was isolated as a yellow solid after recrystallization from ethyl acetate/hexane having an mp = 109-111°C. 

Migration of a benzyl group appears to occur in preference to hydrogen, alkyl, or aryl migration, as with 1,3-diphenyl-2-methyl-1,2- Toxypropane (Eq. 461), which yields 3,4-diphenyl-2-butanone -elusively.1024-102 Of some interest, incidentally, is the report that... 

A TNT explosive was determined in the gas phase using an MIP-QCM chemosensor [127]. The MIP preparation procedure involved dissolution of an appropriate amount of the TNT template, MAA monomer, EGDMA cross-linker and Irgacure 369 [2-benzyl-2-dimethylamino-l-(4-morpholinophenyl)-butanone-l] photoinitiator... 

Ammoniumsalz) und Chlormethyl-benzyl-sulfan in Butanon XII/2, 653 -(3-benzyl-thioureid)-0,0-diethylester XII/2, 798 -O-2-biphenylylester-hydrazid-O-methvlcster XII/2, 802... 

Alkyl ethers of benzoin Benzil dimethyl ketal 2-Hydroxy-2-methylphenol-l-propanone 2,2-Diethoxyacetophenone 2-Benzyl-2-At, V-dimethylamino- l-(4-morpholinophenyl) butanone Halogenated acetophenone derivatives Sulfonyl chlorides of aromatic compounds Acylphosphine oxides and bis-acyl phosphine oxides Benzimidazoles... 

Fig. 5.4. Gas chromatogram of gasoline engine exhaust sample. Peaks 1 = formaldehyde 2,2 = acetaldehyde 3 = acetone 4,4 = propanal 5 = butanone 6 = 2-methylpropenal 7 = benzyl alcohol ...

H. van Bekkum et al. (72) studied a number of catalysts in the Fischer synthesis starting from l-phenyl-2-butanone 40 (with R, = Ph, R2 = CH3) and phenylhydrazine. The isomeric products are the bulky 2-ethyl-3-phenylindole 45 (with R, = Ph, R2 = CH3) and the linear 2-benzyl-3-methylindole 46 (with R, = Ph, R2 = CH3). Catalysis of the inolization of 40 by soluble as well as solid (e.g. Amberlyst 15) catalysts typically yielded a mixture of the two isomers in a bulky/linear ratio of about 75/25. Zeolite BEA reverses this bulky/linear ratio giving 75% of the linear isomer 46, a result interpreted in terms of restricted transition-state selectivity. Although in zeolite BEA the intraporous formation of 45 is largely suppressed, it is in fact probably not completely inhibited. 

The selective Fischer synthesis of 2-benzyl-3-methylindole from l-phenyl-2-butanone and phenylhydrazine and catalyzed by zeolite BEA can be considered as an interesting example of restricted transition state selectivity. 

In water, ionization of the C-Br bond occurs first (Ei mechanism) to give the intermediate resonance-stabilized benzylic zwitterion C. After fast rotation about the C-C bond, carbon dioxide leaves conformer D perpendicularly to the plane of the car-benium ion, to give mainly the most stable ( )-isomer of / -bromostyrene. In butanone, after fast rotation about the C-C bond, elimination of CO2 and Br occurs in a concerted single-step (E2 mechanism) for stereoelectronic reasons (Br and C02 must be anti to one another) to give conformer B, which decomposes exclusively to the thermodynamically less stable (Z)-isomer. In more polar solvents, the partly zwitterionic activated complex, leading to zwitterion C in the rate-determining step, will clearly be more stabilized by solvation than the less dipolar activated complex leading directly to the (Z)-isomer of / -bromostyrene from conformer B [851]. 

Rare earth hydroxides are rarely obtained in nonaqueous systems. However, Djerdj et al. reported the synthesis of La(OH)s nanorods/nanofibers and manganese oxide nanoparticles through a nonaqueous sol-gel process involving the reaction of La(OiPr)3 (lanthanum f-propoxide) and KMn04 with organic solvents such as benzyl alcohol, 2-butanone, and their mixture (Djerdj et al., 2007). 

SYNS 2-BUTANONE, 4-(4-HYDROXYPHENYL)- FE L No. 2588 FR.AMBINONE p-HYDROXY-BENZYL ACETONE 4-(4-HYDROXYPHENYL)-2-BUTANONE l-(p-HYDROXYPHENYL)-3-BUTANONE... 

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