3.3- Dimethyl-2-phenyl-2-butanol

An example of an alcohol that can undergo rapid skeletal rearrangement is 3,3-dimethyl-2-phenyl-2-butanol (Eq. 29). Attempts to reduce this alcohol in dichloromethane solution with l-naphthyl(phenyl)methylsilane yield only a mixture of the rearranged elimination products 3,3-dimethyl-2-phenyl-l-butene and 2,3-dimethy 1-3-phenyl-1 -butene when trifluoroacetic acid or methanesulfonic acid is used. Use of a 1 1 triflic acid/triflic anhydride mixture with a 50 mol% excess of the silane gives good yields of the unrearranged reduction product 3,3-dimethyl-2-phenylbutane, but also causes extensive decomposition of the silane.126 In contrast, introduction of boron trifluoride gas into a dichloromethane solution of the alcohol and a 10 mol% excess of the silane... 

The combination R3SiH/BF3, on the other hand, enables hydrocarbons to be synthesize from their alcohols, for instance, 2-phenyl-3,3-dimethyl-2-butanol affords 2-phenyl-3,3-dimethyl-butane (131)90 ... 

Dimethyl-2-butanol 4-Methyl-2-pentanol 2-Octanol I-Phenylethanol I-Phenvlethanol 1 -(4-Nitrophenyl)ethaiml 4-Phenyl-3-buten-2-ol ... 

The catalyst [l,T-bis(diphenylphosphino)-2-(1-liydroxyethyl)ferrocene](l,5-cyclooctadiene)-rhodium(l +) perchlorate, [Rh(cod)BPPFOII]C104, which is particularly successful in the reduction of ot-amino ketones (see Section 2.3.1.2.7.), hydrogenated 1-phenylethanone to 1-phenyl-ethanol and 3,3-dimethyl-2-butanone to 3,3-dimethyl-2-butanol, both in 43% cc10. 

Dimethylpropanoic acid is the best additive11. Thus, hydrogenation of 1-phenylethanone with the Raney nickel/tartaric acid/sodium bromide/2,2-dimethylpropanoic acid system gave (5>)-l-phenylethanol in 63%ee. 2-Butanone was reduced to (,V)-2-butanol in 49% ee, while the optical inductions in the hydrogenation of 2-alkanones, ranging from 2-pentanone to 2-hene-icosanone, were between 58 and 66% ee. 4-Phenyl-2-butanone was reduced to (S)-4-phenyl-2-butanol in 58% ee, while the best result was achieved with 3,3-dimethyl-2-butanone yielding (S)-3,3-dimethyl-2-butanol in 74% cc11. 

C,Hi40 3,3-Dimethyl-2-butanol 1.48 1 C8H8O7 Phenyl acetate 1.49 1... 

See fert-Butanol, etc. 2-Phenyl-1,1-dimethylethanol 3,5-Dimethyl-3-hexanol, all below... 

AI3-00040, see Cyclohexanol AI3-00041, see Cyclohexanone AI3-00045, see Diacetone alcohol AI3-00046, see Isophorone AI3-00050, see 1,4-Dichlorobenzene AI3-00052, see Trichloroethylene AI3-00053, see 1,2-Dichlorobenzene AI3-00054, see Acrylonitrile AI3-00072, see Hydroquinone AI3-00075, see p-Chloro-rrr-cresol AI3-00078, see 2,4-Dichlorophenol AI3-00085, see 1-Naphthylamine AI3-00100, see Nitroethane AI3-00105, see Anthracene AI3-00109, see 2-Nitropropane AI3-00111, see Nitromethane AI3-00118, see ferf-Butylbenzene AI3-00119, see Butylbenzene AI3-00121, see sec-Butylbenzene AI3-00124, see 4-Aminobiphenyl AI3-00128, see Acenaphthene AI3-00134, see Pentachlorophenol AI3-00137, see 2-Methylphenol AI3-00140, see Benzidine AI3-00142, see 2,4,6-Trichlorophenol AI3-00150, see 4-Methylphenol AI3-00154, see 4,6-Dinitro-o-cresol AI3-00262, see Dimethyl phthalate AI3-00278, see Naphthalene AI3-00283, see Di-rj-butyl phthalate AI3-00327, see Acetonitrile AI3-00329, see Diethyl phthalate AI3-00399, see Tributyl phosphate AI3-00404, see Ethyl acetate AI3-00405, see 1-Butanol AI3-00406, see Butyl acetate AI3-00407, see Ethyl formate AI3-00408, see Methyl formate AI3-00409, see Methanol AI3-00520, see Tri-ocresyl phosphate AI3-00576, see Isoamyl acetate AI3-00633, see Hexachloroethane AI3-00635, see 4-Nitrobiphenyl AI3-00698, see IV-Nitrosodiphenylamine AI3-00710, see p-Phenylenediamine AI3-00749, see Phenyl ether AI3-00790, see Phenanthrene AI3-00808, see Benzene AI3-00867, see Chrysene AI3-00987, see Thiram AI3-01021, see 4-Chlorophenyl phenyl ether AI3-01055, see 1.4-Dioxane AI3-01171, see Furfuryl alcohol AI3-01229, see 4-Methyl-2-pentanone AI3-01230, see 2-Heptanone AI3-01231, see Morpholine AI3-01236, see 2-Ethoxyethanol AI3-01238, see Acetone AI3-01239, see Nitrobenzene AI3-01240, see I idine AI3-01256, see Decahydronaphthalene AI3-01288, see ferf-Butyl alcohol AI3-01445, see Bis(2-chloroethoxy)methane AI3-01501, see 2,4-Toluene diisocyanate AI3-01506, see p,p -DDT AI3-01535, see 2,4-Dinitrophenol AI3-01537, see 2-Chloronaphthalene... 

To a stirred solution of 2,4-dihydro-4- 4-[4-(4-hydroxyphenyl)-l-piperazinyl] phenyl -2-(l-methylpropyl)-3H-l,2,4-triazol-3-one in 100 parts of dimethyl sulfoxide are added 0.3 parts of sodium hydride dispersion 78% and the whole is stirred at 50°C till foaming has ceased. Then there are added 3.7 parts of cis-[2-(2,4-dichlorophenyl)-2-(lH-l,2,4-triazol-l-ylmethyl)-l,3-dioxolan-4-ylmethyl]methanesulfonate and stirring is continued for 3 hours at 100°C. The reaction mixture is cooled and poured onto water. The product is extracted with dichloromethane. The extracts are washed with a diluted sodium hydroxide solution and filtered. The residue is crystallized from 1-butanol. The product yield 4.3 parts (75%) of cis-4- 4-[4- 4-[2-(2,4-dichlorophenyl)-2-(lH-l,2,4-triazol-l-ylmethyl)-l,3-dioxolan-4-ylmethoxy] phenyl -l-piperazinyl]phenyl -2,4-dihydro-2-(methylpropyl)-3H-l,2,4-triazol-3-one. 

Robison, and Robison were the first to prepare 7-azagramine (3-dimethylaminoniethyl-7-azaindole), finding the following procedure to give optimum yields. The azaindole, 10% excess dimethyl-amine hydrochloride, and one molar equivalent of paraformaldehyde are refluxed together in w-butanol for 30 minutes, followed by evaporation under reduced pressure. The residue is extracted with dilute acid, from which the base is precipitated with sodium carbonate. This procedure has been used with only minor variations on a variety of 7-azaindoles. Williamson obtained 7-azagramine in 99% yield on a 0.2-mole scale, compared to 81%. Other 7-azagramines prepared similarly are l-phenyl-4-methyl (72%), ° l-butyl-4-methyl (64%), 6-chloro-4-methyl (60%), 4-methyl (28%), 2-methyl, and 5-methyl (60%). In the case of the last two 4-methyl compounds, it was found that the best yields were obtained with use of a 3 1 molar ratio of dimethylamine hydrochloride and only a 15-minute reflux period. With the 6-chloro-4-methyl isomer, some (6%) of the bis-(7-aza-3-indolyl)methylene by-product was formed. 

Normal nucleophilic substitution reactions of alkyl and aryl chloropyrazines have been examined as follows 2-chloro-3-methyl- and 3-chloro-2,5-dimethyl(and diethyl)pyrazine with ammonia and various amines (535, 679, 680) 2-chloro-3(and 6)-methylpyrazine with methylamine and dimethylamine (681, 844), piperidine and other amines (681, 921) 2-chloro-5(and 6)-methylpyrazine with aqueous ammonia (362) alkyl (and phenyl) chloropyrazines with ammonium hydroxide at 200° (887) 2-chloro-3-methylpyrazine with aniline and substituted anilines (929), and piperazine at 140° (759) 2-chloro-3-methyl(and ethyl)pyrazine with piperidine (aqueous potassium hydroxide at reflux) (930,931) [cf. the formation of the 2,6-isomer( ) (932)] 2-chloro-3,6-dimethylpyrazine with benzylamine at 184-250° (benzaldehyde and 2-amino-3,6-dimethylpyrazine were also produced) (921) 2-chloro-3,5,6-trimethylpyrazine with aqueous ammonia and copper powder at 140-150° (933) and with dimethylamine at 180° for 3 days (934,935) 2-chloro-6-trifluoromethylpyrazine with piperazine in acetonitrile at reflux (759) 2-chloro-3-phenylpyrazine with aqueous ammonia at 200° (535) 2-chloro-5-phenylpyrazine with liquid ammonia in an autoclave at 170° (377) 2-chloro-5-phenylpyrazine with piperazine in refluxing butanol (759) but the 6-isomer in acetonitrile (759) 5-chloro-2,3-diphenylpyrazine and piperidine at reflux (741) and 5-chloro-23-diphenylpyrazine with 2-hydroxyethylamine in a sealed tube at 125° for 40 hours (834). 

Butanol, 2-methyl-4-phenyl-. See Dimethyl phenethyl carbinol... 

Hazardous Decomp. Prods. Heated to decomp., emits acrid smoke and fumes Uses Fragrance in cosmetics synthetic flavoring agent in foods and pharmaceuticals Regulatory FDA 21CFR 172.515 FEMA GRAS Manuf/Distrib. Advanced BioTech http //www.adv-bio.com Dimethyl phenethyl carbinol CAS 103-05-9 EINECS/ELINCS 203-074-4 Synonyms Benzyl-t-butanol 2-Butanol, 2-methyl-4-phenyl- 0,0-Dimethylbenzenepropanol Dimethyl phenylethyl carbinol 1,1-Dimethyl-3-phenylpropanol... 

Dimethyl-3-phenyl-1 -propanol 0,0-Dimethyl-5-phenylpropyl alcohol 2-Methyl-4-phenyl-2-butanol 2-Methyl-4-phenylbutan-2-ol Phenylethyl dimethyl carbinol 2-(2-Phenylethyl )-2-propanol 4-Phenyl-2-methyl-2-butanol 4-Phenyl-2-methyl-butanol-2 1-Propanol, 1,1-dimethyl-3-phenyl-Classification Aromatic alcohol Empirical CnHieO... 

Acetone Amyl formate Benzaldehyde Benzene Benzonitrile Benzyl acetate Bromodichloromethane 2-Butanol Butoxyethanol acetate 1-Butoxyethoxy-2-propanol Butyl alcohol p-t-Butyl toluene Cyclohexane Cyclohexyl acetate Decahydronaphthalene Dibutyl phthalate cis-1,2-Dichloroethylene Diethyl carbonate Diethylene glycol phenyl ether Diethylenetriamine Diethyl oxalaU Diethyl tartrate Diethyl toluamide Dimethyl acetamide Dimethyl adipate... 

Bromobenzene added in one portion at 125-130° to a soln. of K-ferf-butoxide in ferf-butanol-dimethyl sulfoxide whereupon a vigorous exothermic reaction occurs, and after 1 min. poured into water phenyl ferf-butyl ether. Y 42-46%. — This is another example showing the activating effect of dimethyl sulfoxide on base-catalyzed reactions (s. a. Synth. Meth. 17, 106). M. R. V. Sahyun and D. J. Gram, Org. Synth. A5, 89 (1965). 

C-1,4-Phenyl migration. A soln. of 1 g. l,l,5,5-tetraphenyl-3,3-dimethyl-l-pentene in re/ r-butanol irradiated 10 hrs. with the Corex glass-filtered light of a 450 w. Hanovia medium-pressure lamp under deoxygenated Ng -> 150 mg. 1,4,5,5-tetraphenyl-3,3-dimethyl-l-pentene (and 760 mg. recovered startg. m.). H. E. Zimmerman and R. D. Little, Am. Soc. 96, 5143 (1974) C-phenyl migration in 3-chromanones s. A. Padwa and A. Au, Chem. Commun. 1975, 58. 

L (--)-2,2-Dimethyl-4-phenyl-5-hydroxyimino-l,3-dioxane refluxed with excess Na-ferf-butoxide in fe -butanol ( )-2,2-dimethyl-4-phenyl-5-hydroxyimino-1,3-dioxane. Y 85%. T. Kamiya, Chem. Ind. 1961, 256. 

The solventless reaction in the presence of diallq ltin(iv) complexes led to a conversion of 42% with 78% selectivity to diphenyl carbonate. Starting from phenyl acetate, total conversion was obtained at 220 "C with higher selectivity to diphenyl carbonate (95%). Transesterification with higher alcohols was also examined, giving better conversion due to higher nucleophilicity compared to phenol. However, a steric effect was evidenced as fert-butanol was unreactive. Transesterification of ethylene carbonate (l,3-dioxolan-2-one) with methanol to dimethyl carbonate was also reported early. " Today, both transesterifications with methanol and phenol are integrated into the value chain of bisphenol-A polycarbonate production and commercialised by Asahi Kasei Corporation (Scheme 21.12). ... 

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