Benzene-isopropyl-alcohol-water mixture

Because ethyl alcohol forms an azeotrope with water that is a constant boiling mixture, i.e. both the ethyl alcohol and the water, in a ratio of 95/5, boil together at a temperature different than either separately. Other examples in this chapter are the ternary azeotrope, ethyl alcohol - water -benzene and DIPE - isopropyl alcohol - water. An azeotrope mentioned earlier is MEK - water - toluene rafFmate used for toluene extraction. 

Place a mixture of 53 g. of A.R. lactic acid (85-88 per cent, acid), 75 g. (85-5 ml.) of commercial anhydrous isopropyl alcohol, 300 ml. of benzene and 20 g. of Zeo-Karb 225/H (1) in a 700 ml. bolt-head flask, equipped with an automatic water separator (e.g., a large modified Dean and Stark apparatus with a stopcock at the lower end, see Fig. Ill, 126, 1) carrying an efficient reflux condenser at its upper end, and a mercury-sealed stirrer (alternatively, the hquid-sealed stirrer shown in Fig. 11,7,11, c. may be used). Reflux the mixture, with stirring, on a steam bath for 5 hours or until water no longer collects in appreciable amount in the water separator run off the water from time to time. Filter off the resin at the pump and wash it with two 25 ml. portions of benzene. Shake the combined filtrate and washings with about 5 g. of precipit-ated calcium... 

A mixture of 20 g (0.1 mol) of aluminum isopropoxide, 0.1 mol of an aldehyde or a ketone and 100 ml of dry isopropyl alcohol is placed in a 250 ml flask surmounted by an efficient column fitted with a column head providing for variable reflux. The mixture is heated in an oil bath or by a heating mantle until the by-product of the reaction - acetone - starts distilling. The reflux ratio is adjusted so that the temperature in the column head is kept at about 55° (b.p. of acetone) and acetone only is collected while the rest of the condensate, mainly isopropyl cohol (b.p. 82°), flows down to the reaction flask. When no more acetone is noticeable in the condensate based on the test for acetone by 2,4-dinitrophenylhydrazine the reflux regulating stopcock is opened and most of the isopropyl alcohol is distilled off through the column. The residue in the distilling flask is cooled, treated with 200 ml of 7% hydrochloric acid and extracted with benzene the benzene extract is washed with water, dried and either distilled if the product of the reduction is volatile or evaporated in vacuo in the case of non-volatile or solid products. Yields of the alcohols are 80-90%. 

A dilute solution of ethanol is obtained, which can be concentrated by distillation to a constant-boiling point mixture that contains 95.6% ethanol by weight. Dehydration of the remaining few percent of water to give absolute alcohol is achieved either by chemical means or by distillation with benzene, which results in preferential separation of the water. Ethanol also is made in large quantities by fermentation, but this route is not competitive for industrial uses with the hydration of ethene. Isopropyl alcohol and tert-butyl alcohol also are manufactured by hydration of the corresponding alkenes. 

This mixture is then diluted with water, washed with ethyl acetate, acidified with dilute sulfuric acid, and finally extracted with benzene. The benzene extract is washed with water, dried over anhydrous sodium sulfate, and evaporated to dryness at reduced pressure to produce crude 17 3-hydroxy-17a-methyl-l-oxo-l,2-seco-A-nor-5a-androstan-2-oic acid, which after recrystallization from aqueous isopropyl alcohol melts at about 166° to 173°C (decomposition). 

A solution of 8.2 g. (0.040 mole) of purified aluminum isopropoxide and 2.75 g. (0.011 mole) of 4-keto-l,2,3,4-tetrahydrochrysene in 25 cc. of dry toluene is refluxed for four hours, in an oil bath. After the solution has cooled slightly, 25 cc. of dry isopropyl alcohol is added to facilitate removal of acetone, the water is removed from the reflux condenser, and a water condenser set for downward distillation is attached to the top by means of a short bent tube (a Hahn partial condenser with a 1-cm. layer of isobutyl alcohol in the inner condensing tube may be used). The mixture is heated at such a rate that slow distillation occurs (2 to 5 drops per minute, the volume of solution should be maintained by further addition of solvent as needed). When the test for acetone is completely negative, f the toluene solution is cooled and the aluminum salt is decomposed with cold 10% sulfuric acid (from 5 cc. of concentrated sulfuric acid and 80 cc. of water). The product is separated with the toluene, and the solution is washed with dilute aqueous ammonia and water, and then evaporated at room temperature under a stream of air (solutions of secondary alcohols which are susceptible to dehydration should be evaporated at room temperature a stream of air should not be used with carbinols boiling below 200°). There is obtained 2.10 g. (76%) of colorless 4-hydroxy-l, 2,3,4-tetrahydrochrysene melting at 156-158°. Two recrystallizations from a mixture of benzene and petroleum ether bring the melting point to 160-162°. 

Reaction of phenylacetylene with Te/KOH/SnCf. A mixture of 6.4 g of tellurium, 42 g of potassium hydroxide, 22.6 g of SnCl2-2H20,10.2 g of phenylacetylene, 20 mL of toluene, 60 mL of water and 1.2 g of Adogen 464 was heated (80-97°C) with vigorous stirring for 7 h. The organic layer was separated, and the aqueous layer was extracted with benzene. The benzene was removed under vacuum. The residue was dissolved in a small amount of ether, poured into 200 mL of isopropyl alcohol, and placed in the refrigerator for 3 days. The yellow crystals of distyryl telluride (2.5 g, yield 15%) and the red needle crystals of distyryl ditelluride (0.7 g, yield 6%) were separated. 

Commercial product is a yellow liq mixture of cis- and traits isomers, the cis-isomer being about 100 times more potent in insecticidal activity than the trans-isomer Casida el at. J. Agr. Food Chem. 4, 236(1956). df 1.25. ng 1.4494. bp, 106-107.5. Misc with water, acetone, benzene, carbon tetrachloride, chloroform, ethyl and isopropyl alcohols, toluene and xylene. One gram dissolves in 20 ml carbon disulfide and 20 ml kerosene. Practically insol in hexane. LD in female, male rats 3.7, 6.1 mg/kg orally 4.2, 4.7 mg /kg dermal] y, T. B. Gaines, Toxicol. Appl PharmacoL 14, 515 (1969). 

PHYSICAL PROPERTIES colorless to yellow liquid weak odor commercial product is a yellow liquid mixture of the cis- and trans isomers miscible with water, benzene, acetone, carbon tetrachloride, chloroform, ethyl and isopropyl alcohols, toluene and xylene practically insoluble in hexane MP (-56°C, -69°F) BP (325°C, 617°F at 760 mmHg) DN (1.25 g/mL at 20°C) LSG (1.25) VD (NA) VP (0.003 mmHg at 20°C) OT (NA). 

Figure 1.12 shows a liquid-liquid-vapor phase diagram of isopropyl alcohol (l)-benzene (2)-water (3) mixture. Figure 1.12 shows the critical point of liquid-liquid equilibrium (cr) in which the compositions of two equilibrium liquid phases are identical. The thin line shows the vapor line for the region of two liquid phases Reg. On this line, there are points of compositions of vapor that... 

Figure 2.13b shows a structure of concentration space of mixture benzene (entrainer) (1) -isopropyl alcohol(2)-water(3). The mixture has a ternary azeotrope and three binary azeotropes. 

Furfuryl acetate. Reflux a mixture of 39 2 g. (34 8 ml.) of redistilled furfuryl alcohol, 48 g. of glacial acetic acid, 150 ml. of benzene and 20 g. of Zeo-Karb 225/H in a 500 ml. bolt-head flask, using the apparatus described under isoPropyl Lactate. After 3 hours, when the rate of collection of water in the water separator is extremely slow, allow to cool, separate the resin by suction filtration, and wash it with three 15 ml. portions of benzene. Remove the benzene, etc., from the combined filtrate and washings under reduced pressure (water pump) and then collect the crude ester at 74-90°/10 mm. a small sohd residue remains in the flask. Redistil the crude ester from a Claisen flask with fractionating side arm pure furfuryl acetate passes over at 79-80717 mm. The yield is 14-5 g. 

Pyrethroid Esters of Benzene Acetate. These insecticides have more extensive structural optimization in both acid and alcohol moieties. Fenvalerate [51630-58-1]y 0t-cyano-(3-phenoxyphenyl)methyl (+)-(2R,T)-a-isopropyl-4-chlorophenylacetate (24) (d 1.17, vp 1.4 J,Pa at 25°C), a mixture of four isomers, is soluble in water to 0.3 mg/L The rat oral LD ( is 450 mg/kg. Esfenvalerate [66230-04-4] is the (+)-2-(3, 3)-isomer (mp 59°C). The rat LD5Qs are 75, 458 (oral), and the rabbit dermal LD50 is 2000 mg/kg. These pyrethroids are widely used general-purpose insecticides for field, vegetable, and fruit crops. 

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