Alcohol removal

Place 35 ml. of a M solution of aluminium tsopropoxide or 7 g. of solid aluminium tsopropoxide, 450 ml. of dry isopropyl alcohol and 21 g. of purified benzaldehyde (Section IV,115) in a 1 litre round-bottomed flask. Fit a short reflux condenser (no water in the cooling jacket) or better a Hahn condenser (2) (containing a 1 cm. layer of ethyl alcohol in the iimer tube) to the flask and arrange for slow distillation from a water bath at the rate of 3-6 drops per minute. Continue the heating until a negative test for acetone is obtained after 5 minutes of total reflux (6-9 hours) if the volume of the mixture falls below 200 ml. during the reduction, add more isopropyl alcohol. Remove the reflux or Hahn condenser and distil off (Fig. II, 13, 3) most of the isopropyl alcohol under atmospheric pressure from a suitable oil bath. Hydrolyse the... 

Fig. 2. Schematic of alcohol reduction ia beverages. Countercurrent dialysis is combiaed with distillation. The separation process is isothermal, and high boiling iagredients, present ia the dialysate, are preserved. In this fashion, alcohol removal is accompHshed with minimal perturbation ia flavor.

Cross-conjugated dienones are quite inert to nucleophilic reactions at C-3, and the susceptibility of these systems to dienone-phenol rearrangement precludes the use of strong acid conditions. In spite of previous statements, A " -3-ketones do not form ketals, thioketals or enamines, and therefore no convenient protecting groups are available for this chromophore. Enol ethers are not formed by the orthoformate procedure, but preparation of A -trienol ethers from A -3-ketones has been claimed. Another route to A -trien-3-ol ethers involves conjugate addition of alcohol, enol etherification and then alcohol removal from la-alkoxy compounds. 

The above keto-nitrile (15 grams) was methylated with a solution of diazomethane in ether. (The diazomethane solution was prepared using 20 grams of N-nitrosomethylurea.) The ether and excess diazomethane were evaporated on the steam bath and the oil dissolved in ethanol (50 ml). To this was added a solution of guanidine in ethanol (100 ml) (prepared from 8.1 grams of the hydrochloride). The solution was refluxed for 5 hours, the alcohol removed and the residue treated with 5N sodium hydroxide. The insoluble material was then filtered. After purification by precipitation from dilute acetic acid with sodium hydroxide and by recrystallization from ethanol the product formed clear colorless needles (8.0 grams), MP 218°-220°C as described in U.S. Patent 2,602,794. 

A solution of 19.5 g. (0.1 mole) of ethyl />-nitrobenzoate (Note 1) in 150 cc. of 95 per cent alcohol is placed in the reaction bottle of the catalytic reduction apparatus (p. 10) and 0.2 g. of platinum oxide catalyst (p. 92) is added. The mixture is shaken with hydrogen until three molecular equivalents have been absorbed. The time required is about seven minutes. The platinum is filtered off and the alcohol removed from the filtrate by distillation. The ethyl p-aminobenzoate, recrystallized from about 40 cc. of ether, melts at 89-90°. The yield is 15-16.5 g. (91-100 per cent of the theoretical amount). 

Beck and Brink [28] have described a sensitive method for the routine assay of cobalamins in activated sewage sludge. The method involves extraction with benzyl alcohol, removal of interfering substances using a combination of gel filtration and chromatography on alumina, concentration of the extract by lyophilization, and direct determination of total cobalamin by high-speed liquid chromatography, in comparison with cobalamin standards. 

It is appropriate here to compare the acidity of cyclopentadiene, which has pATa 16, considerably more acidic than most hydrocarbon systems and comparable to water and alcohols. Removal of one of the CH2 protons from the non-aromatic cyclopentadiene generates the cyclopentadienyl anion. This anion has an aromatic sextet of electrons, two electrons being contributed by the negatively charged carbon (see Section 2.9.3). 

Alcohol is a complicated drug. Although actually a depressant rather than a stimulant, alcohol removes inhibitions so that people under its influence are often quick to express anger and to fight, as well as being more likely to engage in possibly unsafe sex. The impairment of judgment and reflexes also increases the chances of involvement in traffic accidents. 

An electrometric method for determining soluble sulphates consists in precipitation of the latter by the addition of a measured excess of a standard solution of lead nitrate in the presence of alcohol, removing the lead sulphate by filtration, washing it with alcohol, and titrating the unchanged lead nitrate in the filtrate electrometrically with standard ferroeyanide solution.6... 

The 55% ethanol extracted 6.91% of the weight of average oven-dry American oak (Table III). In flavoring 1 liter of California port wine for one taster, an average of 575 mg of this wood, 38 mg of its solid, or 13 mg of its phenols extractable by 55% alcohol produced a just detectable difference. A series of five samples of European oak in comparable analyses averaged 11.37% extractable solids, and 1 liter of the same port wine was just detectably flavored by 515 mg of oven-dry wood, 51 mg of extractable solid, or 30 mg of phenol. The fact that European oak contributes more extract and more tannin to wine and yet, per unit of extract or phenol, less flavor is clear from these data. This agrees with tasters opinions and is believed to be because American oak contributes considerably more oak odor per unit of tannin. The amount of flavor per unit of wood is about the same, but the European oak counteracts less flavor per unit of extract by its high extract content. In other tests, 12% alcohol removed 49% as much extract as did 55% alcohol from American oak and 71% as much from French. In earlier tests (47) about 63% as much extract was obtained from American oak by 12% alcohol as by 55% alcohol. Whether these extracts would have the same flavor value has not yet been studied. 

Exercise 29-18 Treatment of polychloroethene with zinc in alcohol removed 85% of the chlorine as zinc chloride without formation of unsaturated polymer. What does this result indicate about the polymer structure Would you have expected that all of the chlorine would be removed by the zinc treatment Explain. (See Section 14-10C.)... 

Treatment with ale is superior to drying with air (see methods a, b, c), not only because it is safer, but also because alcohol removes water and some undesirable impurities as well. These impurities consist mostly of cellulose nitrates of low nitrogen content, which are unstable and have a tendency to reduce the ballistic potential of propints manufd from NC contg them (Ref 2, pp 2134 2142-43) This method is based on USP 516924 (1894) of F. DuPont (cited in Ref 2, p 2134)... 

The 14-hydroxydihydronormorphinone was suspended in 200 cc of pure ethyl alcohol, half its weight of sodium bicarbonate and half its weight of allyl bromide added and the resulting mixture was refluxed at about 75°C for 48 hours. The solution was cooled, e.g., to 10°C and filtered and the alcohol removed under a vacuum of 30 mm. The residue was dissolved in chloroform and filtered. The chloroform was removed under a vacuum of 30 mm and the residue was crystallized from ethylacetate. The crystallized product, N-allyl-1,4-hydroxydihydronormorphinone, has a melting point of 184°C, is soluble in chloroform and insoluble in petroleum ether. The yield amounts to 20% based on the weight of the reacted 14-hydroxydihydromorphinone. 

In the reduction of ketones, boiling isopropyl alcohol is generally satisfactory. In the few instances in which the temperature must be raised above this point to bring about reduction (that is, if no acetone has been detected after an hour of heating), dry toluene may be added and the isopropyl alcohol removed by distillation. If reduction still does not occur xylene may be substituted, but this is rarely necessary and may result in... 

For a practical transesterification reaction, next to high yields, an equimolar ratio of the reactants is desirable. The catalyst should be neutral and easily separable, and no special technology for alcohol removal should be needed [11]. These requirements are fulfilled by the fluorous tagged distannoxane catalyst 6. Transesterification yields are quantitative and the FC-72 solution (FC-72 and FC-75 are commercially available mixtures of perfluoroalkanes) of the catalyst can be reused. 

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