3- -2-tetralone

To the cold acid chloride add 175 ml. of pure carbon disulphide, cool in ice, add 30 g. of powdered anhydrous aluminium chloride in one lot, and immediately attach a reflux condenser. When the evolution of hydrogen chloride ceases (about 5 minutes), slowly warm the mixture to the boiling point on a water bath. Reflux for 10 minutes with frequent shaking the reaction is then complete. Cool the reaction mixture to 0°, and decompose the aluminium complex by the cautious addition, with shaking, of 100 g. of crushed ice. Then add 25 ml. of concentrated hydrochloric acid, transfer to a 2-htre round-bottomed flask and steam distil, preferably in the apparatus, depicted in Fig. II, 41, 3 since the a-tetralone is only moderately volatile in steam. The carbon disulphide passes over first, then there is a definite break in the distillation, after which the a-tetralone distils completely in about 2 litres of distillate. 

Separate the oil, and extract the aqueous layer with three 100 ml. portions of benzene. Combine the oil and benzene extracts, dry with anhydrous magnesium sulphate, remove the solvent, and distil the residue under diminished pressure. Collect the a-tetralone at 105-107°/2 mm. (or at 135-137°/15 mm.). The yield is 23 g. 

Y-Phenylbutyric acid. Prepare amalgamated zinc from 120 g. of zinc wool contained in a 1-litre rovmd-bottomed flask (Section 111,50, IS), decant the liquid as completely as possible, and add in the following order 75 ml. of water, 180 ml. of concentrated hydrochloric acid, 100 ml. of pure toluene (1) and 50 g. of p benzoylpropionic acid. Fit the flask with a reflux condenser connected to a gas absorption device (Fig. II, 8, l,c), and boil the reaction mixture vigorously for 30 hours add three or four 50 ml. portions of concentrated hydrochloric acid at approximately six hour intervals during the refluxing period in order to maintain the concentration of the acid. Allow to cool to room temperature and separate the two layers. Dilute the aqueous portion with about 200 ml. of water and extract with three 75 ml. portions of ether. Combine the toluene layer with the ether extracts, wash with water, and dry over anhydrous magnesium or calcium sulphate. Remove the solvents by distillation under diminished pressure on a water bath (compare Fig. II, 37, 1), transfer the residue to a Claisen flask, and distil imder reduced pressure (Fig. II, 19, 1). Collect the y-phenylbutyric acid at 178-181°/19 mm. this solidifies on coohng to a colourless sohd (40 g.) and melts at 47-48°. 

Checked by James Cason, William G. Dauben, Bradford H. Walker, and Charles E. Stehr. 

In a dry 2-1. three-necked round-bottomed flask, fitted with a gas-tight stirrer and a reflux condenser carrying at the top a calcium chloride drying tube connected to a gas-absorption trap (a good hood is preferable), are placed 98.5 g. (0.6 mole) of 

The cooled reaction mixture is separated in a separatory funnel, and the aqueous phase is extracted with three 50-ml. portions of benzene. These extracts are combined with each other but kept separate from the original organic phase each wash solution is used first with the original organic phase, then the extracts. The washes are 150 ml. of water (Note 4), 100 ml. of 10% sodium carbonate solution, 100 ml. of water, and finally 50 ml. of saturated sodium chloride solution (Note 5). Solvent is distilled from the combined extracts, and the residue is distilled at reduced pressure in a Claisen flask. The yield of a-tetralone, b.p. 135— 137°/15 mm., 1.5671-1.5672, is 75-80 g. (85-91%). 

A total of 350 ml. of dry benzene is required. It may be dried by allowing it to stand for a few days with about 1 g. of 

It is convenient to weigh the phosphorus pentachloride in an Erlenmeyer flask which is then attached to a side neck of the three-necked flask by a 6-in. length of wide-bore thin-walled rubber tubing. 

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With Friedel-Crafts catalysts, butyrolactone reacts with aromatic hydrocarbons. With ben2ene, depending on experimental conditions, either phenylbutyric acid or 1-tetralone can be prepared (162). 

The most important process to produce 1-naphthalenol was developed by Union Carbide and subsequently sold to Rhc ne-Poulenc. It is the oxidation of tetralin, l,2,3,4-tetrahydronaphthalene/719-64-2] in the presence of a transition-metal catalyst, presumably to l-tetralol—1-tetralone by way of the 1-hydroperoxide, and dehydrogenation of the intermediate ie, l-tetralol to 1-tetralone and aromatization of 1-tetralone to 1-naphthalenol, using a noble-metal catalyst (58). 1-Naphthol production in the Western world is around 15 x 10 t/yr, with the United States as the largest producer (52). 

Examples of palladium-catalyzed reduction are 4-chloro-2,6-di-r-butyl-phenol to 2,6-di-t-butylcyclohexanone (750 psig, 25 C) with loss of halogen 24), 1,8-dihydroxynaphthalene to 8-hydroxy-1-tetralone 30), and 2,4-dimethylphenol to 2,4-dimethylcyclohexanone (27). 

Cyclobutane Butyrolactone Butyr aldehyde Succinic acid 1-Tetralone Carbonyls... 

This method fails, however, with bicyclic ketones such as 1-tetralones even in the presence of TsOH, affording only enol trimethylsilyl ethers such as 107 a [114, 115]. A subsequent investigation revealed that cyclohexanone reacts with equivalent amounts of N-trimethylsilyldimefhylamine 463 in the presence of TMSOTf 20 at -30 °C to give the enol silyl ether 107 a, whereas reaction of cyclohexanone, benzaldehyde, and chlorodimethyl ether with 463 and TMSOTf 20 or TCS 14 at 1-20 °C afforded the iminium salts 547, 548, and 549 in high yield [116-118]. Analogously, N-trimethylsilylpyrrolidine 550 and N-trimethylsilylmorphoHne 294 convert aldehydes such as benzaldehyde, at ambient temperature in the presence... 

The effect of chelating polyamines on the rate and yield of benzylation of the lithium enolate of 1-tetralone was compared with HMPA and DMPU. The triamine... 

Reaction of 1-tetralone with aryl cyanides or methyl thiocyanate, followed by aromatisation with DDQ gave good yields of benzoquinazolines. The further transformation of the methylthio product 31, via oxidation and selective sequential nucleophilic substitution of the resulting sulfones, illustrates the utility of this substituent. 2-Tetralone reacted similarly but substantial amounts of by-products were formed <06T2799>. 

In the determination of carbohydrates, sensitivity can often be increased by using fluorescence rather than absorbance for the final determination. With compounds that are not normally fluorescent, it becomes necessary to find fluorescent derivatives. Hirayama [160] concentrated the carbohydrates in coastal water samples, using electrodialysis and evaporation, and made fluorescent derivatives using anthrone and 5-hydroxyl-1-tetralone, determining pentoses separately from hexoses in the process. While this method does seem to have the extra sensitivity expected from fluorescent methods, the extra manipulations render it unsatisfactory for routine use. 

The bath was cooled to —78 °C and a solution of 2-uobutylidene-1 -tetralone (200 mg) in anhydrous toluene (2mL) was added via a syringe to the cold mixture. The reaction mixture was stirred at this temperature for 30 minutes... 

The most widely used route to l-benzazepin-2-ones involves the Beckmann or Schmidt reaction of the easily accessible 1-tetralones. Many biologically active compounds described in this review have been prepared on the basis of these reactions they have been fully reviewed [2], In the Beckmann reaction of 1-tetralone oximes, polyphosphoric acid is used as a catalyst-solvent in most instances. Aryl migration generally takes precedence over alkyl migration under these reaction conditions, and various 1-tetralone oximes substituted on the aromatic and/or aliphatic rings can be converted to the appropriate 2,3,4,5-tetrahydro-l//-l-benzazepin-2-ones (51) [5, 20-23, 36, 59, 65, 80, 107-112]. Both courses of the rearrangement occur in some instances, yielding l-benzazepin-2-ones (51) and the isomeric 2-benzazepine-l-ones, probably due to electronic effects of the substituents [90, 113, 114]. 

The Schmidt reaction is also applied to a variety of 1-tetralones, yielding (51). The use of sodium azide in acetic acid and sulphuric acid [7, 12, 13, 30, 34, 36, 37, 72, 73, 84] is preferable to the procedure in the earlier stage, in which hydrazoic acid, sulphuric acid and chloroform are employed [115]. Other acidic reagents such as polyphosphoric acid [116, 117], sulphuric acid [116, 118], methasulphonic acid [119] and trichloroacetic acid [116] are used in some cases. Variation of substituents affects the course of the rearrangement 6-methoxytetralones are rather liable to afford the isomeric 2-benzazepine-l-ones in preference to the desired (51) [ 7, 116, 118]. The Schmidt reaction is also conveniently applied to various 1,4-naphthoquinones and yields a wide range of 2,5-dihydro-l-benzazepin-2,5-diones [85, 120-122]. 

The autoxidation of cyclic ketones with dirhenium decacarbonyl under basic catalytic conditions produces dicarboxylic acids (68-73%) bicyclic ketones are converted into keto carboxylic acids and, when one ring is aromatic, quinones are obtained, e.g. 1-tetralone produces 2-hydroxy-1,4-naphthaquinone (93%), and H02C(CH2)4C0(CH2)3C02H (85%) is obtained from 1-decalone via a cyclic triketone [5]. 

Streptomyces griseus NRRL 8090 catalyzes a series of biotransformations of naphthalene and 2-methyl-1,4-naphthaquinone to their corresponding racemic and diastereomeric 4-hydroxy-1-tetralones (Figure 12.1). The yields of 4-hydroxy-l-tetralone obtained with S. griseus are much higher than those produced by various fungi that oxidize naphthalene. ... 

Gopishetty, S.R., Heinemann, J., Deshpande, M. and Rosazza, J.P.N., Aromatic oxidations by Streptomyces griseus biotransformations of naphthalene to 4-hydroxy-1-tetralone. Enzyme Microbiol TechnoL, 2007, 40, 1622. 

For gas chromatography analysis, samples were spiked with 2-methyl-naphthalene as an internal standard. Samples were analyzed using a Shimadzu GC-17A series gas chromatograph equipped with RTX-5 column, 15 m (length) 0.25 mm (i.d.) and 0.25 pm (film thickness). The initial column temperature was 70 °C and temperature was increased at 20 °C min 300 °C, and column temperature was held for 13 min. Retention times R naphthalene, 3.2 min 2-methyl-naphthalene, internal standard, 4.09 min 1-tetralone, 4.7 min menadione, 5.68 min 1-naphthol, 5.7 min 4-hydroxy-1-tetralone, 6.1 min and 2-methy 1-4-hydroxy-1-tetralone, 6.18,6.27,6.3 and 6.4 min. 

For qualitative analyses, the GC system was equipped with a J W Scientific HP-5 or a Supelco Simplicity 1 fused-silica capillary column. Injector and detector temperatures were set at 220 °C and 240 °C respectively the oven temperature was programmed from 60 to 230 °C at 40 °C min V Helium was employed as carrier gas (1 mL min ). Compound identification was based on a comparison of mass spectra with those of synthetic racemic and enantiomeric-enriched samples. The retention times for tetralin, 1-tetralol and 1-tetralone were 5.6 min, 6.5 min and 6.6 min respectively. 

The cmde residue was purified by flash column chromatography on silica gel using 300 mL portions of hexane ethyl acetate (90 10 and 80 20) 10 mL fractions were collected, giving 1-tetralone with 9 1 ratio and 1-tetralol (38 mg, 0.287 mmol) with 8 2 ratio. 

Tetralone oxime, reduction with lithium aluminum hydride, 48, 23... 

Fluorination of the sodium enolate of 2-methyl-1-tetralone by (-)-A-tluoro-2,10-(3,3-dichlorocamphorsultam) gives (5 )-(- -)-2-iluoro-2-methyl-1-tetralone in 70% ee, which corresponds to the opposite asymmetric induction to that achieved using non-racemic (camphorsulfonyl)oxaziridines as closely related hydroxylation reagents. ... 

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