Benzoic acid extractant

Addition of HC1 to the benzoic acid extract will produce huge amounts of white crystals. Get out the Buchner funnel and have a field day Collect all you want. But they won t be in the best of shape. Recrystallize them. ("Note This compound is insoluble in the aqueous recovery solution.)... 

Ethyl 4,5-Dlbenzamldopent 4-enoate (2) Ethyl 3-imidazol-4(5)-ylpropanoate 1 (9.2 g, 54 rnnwl) in ElOAc (140 ml) was treated with benzoyl chloride (IS 7 g, 112 mmol) in ElOAc (40 mL) and 1M NaHCOs (380 ml) added simultaneously In 1 h under ice-cooling. The reaction mixture was stirred for 1 h, then a further portion olbenzoyichionde (15 7 g, 112 mmol) in EtOAc) and 1M NaHCOs (280 mL) was added in the same manner, followed by an additional portion of 1M NaHCOs (200 mL) The reaction mixture was stirred for 24 h, then the organic layer was separated, concentrated, and the residue dissolved in THF (300 mL) The THF solution was stirred with 10% NaHCOa (600 mL) for 24 h to decompose any N-lormyl intermediate and to remove benzoic acid Extraction with EtOAc, drying (Na2S04), solvent evaporation and recrystallization of the residue from EtOAc hexane afforded 16 24 g of 2 (84%), mp 128-129 C... 

The benzoic acid extracted from 106.3 g of catsup required a 14.76-mL titration with 0.0514 M NaOH. Express the results of this analysis in terms of percent sodium benzoate (144.10 g/mol). 

Benzoic acid extracted from orange juice was the subject of a collaborative study that used a PRP-1 colunm (2. = 230 nm) and a 40/60 acetonitrile/water (SOn M phosphate buffer at pH 2.3) mobile phase [1048]. Elution was complete in <8 min and a detection limit of 0.5 ppm (S/N = 10] was reported. The working range was 0.5-10 ppm. 

Efforts have also been made to avoid the need of preservatives, such as, for example, irradiating the cosmetic products or preserving them in special packaging. There is also an increase in the use of naturally derived preservatives, like for example, benzoic acid extracted from cranberries, which would avoid using toxic impurities that may remain as residues coming from the raw materials used in synthesis. 

To obtain the benzoic acid, add an excess of concentrated hydrochloric acid carefully with stirring to the aqueous alkaline solution remaining from the original extraction. When no further precipitation of benzoic acid occurs, cool the solution (if perceptibly warm) in ice-water, and then filter at the pump. Wash the benzoic acid thoroughly with cold water, drain, and then recrystallise from a large volume of boiling water. Benzoic acid is obtained as colourless crystals, m.p, 121° yield, 19-20 g. 

Benzoates. Dissolve 0-5 g. of the amino acid in 10 ml. of 10 per cent, sodium bicarbonate solution and add 1 g. of benzoyl chloride. Shake the mixture vigorously in a stoppered test-tube remove the stopper from time to time since carbon dioxide is evolved. When the odour of benzoyl chloride has disappeared, acidify with dilute hydrochloric acid to Congo red and filter. Extract the solid with a little cold ether to remove any benzoic acid which may be present. RecrystaUise the benzoyl derivative which remains from hot water or from dilute alcohol. 

Hydrolysis of benzanilide. Place 5 g. of benzanilide and 50 ml. of 70 per cent, sulphuric acid in a small flask fitted with a reflux condenser, and boU gently for 30 minutes. Some of the benzoio acid will vapourise in the steam and solidify in the condenser. Pour 60 ml. of hot water down the condenser this will dislodge and partially dissolve the benzoic acid. Cool the flask in ice water filter off the benzoic acid (anifine sulphate does not separate at this dilution), wash well with water, drain, dry upon filter paper, and identify by m.p. (121°) and other tests. Render the filtrate alkaline by cautiously adding 10 per cent, sodium hydroxide solution, cool and isolate the aniline by ether extraction. Recover the ether and test the residue for anifine (Section IV,100). 

The carbon tetrachloride extraction removes any benzoic acid which may be present. 

If the benzoyl derivative is soluble in alkali, precipitate it together with the benzoic acid derived from the reagent by the addition of hydrochloric acid filter and extract the product with cold ether or light petroleum (b.p. 40-60°) to remove the benzoic acid. 

Pour the aqueous solution remaining from the ether extraction with stirring into a mixture of 80 ml. of concentrated hydrochloric acid, 80 ml. of water and about 100 g. of crushed ice. Filter the precipitated benzoic acid at the pump, wash it with a little cold water, drain, and recrystallise from boiling water. The yield of benzoic acid (colourless crystals), m.p. 121°, is 18g. 

The benzoic acid may be separated by steam distillation or by saturating the aqueous mixture of sodium salts with sulphur dioxide whilst maintaining the temperature below 40° the benzoic acid precipitates and can be separated by filtration or extraction with ether. Acidification of the filtrate with hydrochloric acid liberates the pyruvic acid. The pjTuvic acid may be oxidised < lth hydrogen peroxide to the arylacetic acid, for example ... 

Separations based upon differences in the chemical properties of the components. Thus a mixture of toluene and anihne may be separated by extraction with dilute hydrochloric acid the aniline passes into the aqueous layer in the form of the salt, anihne hydrochloride, and may be recovered by neutralisation. Similarly, a mixture of phenol and toluene may be separated by treatment with dilute sodium hydroxide. The above examples are, of comse, simple apphcations of the fact that the various components fah into different solubihty groups (compare Section XI,5). Another example is the separation of a mixture of di-n-butyl ether and chlorobenzene concentrated sulphuric acid dissolves only the w-butyl other and it may be recovered from solution by dilution with water. With some classes of compounds, e.g., unsaturated compounds, concentrated sulphuric acid leads to polymerisation, sulphona-tion, etc., so that the original component cannot be recovered unchanged this solvent, therefore, possesses hmited apphcation. Phenols may be separated from acids (for example, o-cresol from benzoic acid) by a dilute solution of sodium bicarbonate the weakly acidic phenols (and also enols) are not converted into salts by this reagent and may be removed by ether extraction or by other means the acids pass into solution as the sodium salts and may be recovered after acidification. Aldehydes, e.g., benzaldehyde, may be separated from liquid hydrocarbons and other neutral, water-insoluble hquid compounds by shaking with a solution of sodium bisulphite the aldehyde forms a sohd bisulphite compound, which may be filtered off and decomposed with dilute acid or with sodium bicarbonate solution in order to recover the aldehyde. 

Chemical Equilibria. In many cases, mass transfer between two Hquid phases is accompanied by a chemical change. The transferring species can dissociate or polymerize depending on the nature of the solvent, or a reaction may occur between the transferring species and an extractant present in one phase. An example of the former case is the distribution of benzoic acid [65-85-0] between water and benzene. In the aqueous phase, the acid is partially dissociated ... 

The USP/FCC grade of benzoic acid is usually produced by extraction and crystalliza tion, although distillation has also been used. In the extraction—crystallization process, toluene, water, and methanol have all been used and each is capable of producing a high quaUty benzoic acid product. 

Snia Viscosa. Catalytic air oxidation of toluene gives benzoic acid (qv) in ca 90% yield. The benzoic acid is hydrogenated over a palladium catalyst to cyclohexanecarboxyhc acid [98-89-5]. This is converted directiy to cmde caprolactam by nitrosation with nitrosylsulfuric acid, which is produced by conventional absorption of NO in oleum. Normally, the reaction mass is neutralized with ammonia to form 4 kg ammonium sulfate per kilogram of caprolactam (16). In a no-sulfate version of the process, the reaction mass is diluted with water and is extracted with an alkylphenol solvent. The aqueous phase is decomposed by thermal means for recovery of sulfur dioxide, which is recycled (17). The basic process chemistry is as follows ... 

Flynn and Treybal [Am. Inst. Chem. Eng. J., I,. 324 (1955)]. Continuous extraction of benzoic acid from toluene and kerosine into water baffled vessels, turbine agitators. Stage efficiency is correlated with agitator energy per unit of liquid treated. 

FIG. 15-38 Extraction rates for sieve-plate and modified biihhle-plate columns. System benzoic acid-water-toliiene, except where noted. To convert feet to meters, multiply by 0.3048 to convert inches to centimeters, multiply by 2.54. [Alletion, Strom, and Treyhal, Trans. Am. Inst. Cbem. Eng., 39, 361 (1943) Row, Kojfolt, and Withrow, ihid., 37, 559 (1941) Treyhal and Dumoulin, Ind. Eng. Cbem., 34, 709(1942).]... 

N-(4 Methoxyphenyl)-N-benzoyl-3-chloro-3-chloroantranlllc acid (4) 2 To ice cooled NaoEt (Irom 0 11 g Na and 10 mL ElOH) was added in rapid succession meltiyl 2 chloro 6 hydroxybenzoate 2 (0 86 g 4 7 mmol) and N (4 methoxyphenyl)benzimidyl chloride 1 (t 14 g 4 7 mmol) in EI2O (30 mL) The mixture was stirred vigorously and allowed to stand at rt tor 48 h The oily solid obtained alter evaporation was heated to 210 215°C lor 70 min under N2 The product was diluted with water (5 4 mL) ElOH (10 8 mL) and treated with 1 M NaOEt (5 4 mL) The mixture was relluxed lor 90 mm the solvent evaporated and the aqueous solution acldilied The dark oil was heated with NaOH (7 5 g) m EtOH (22 mL) Alter removal ol benzoic acid by exhaustive extraction with water the product was recrystallized Irom EtOH to give 0 36 g ol 4 (27 7%), mp 139 5 140 5°C... 

Heteratisine, C22H33O5N, crystallises in prisms, has m.p. 262-7° (dec.), [a]f7° + 40° (MeOH), forms a hydrochloride, m.p. 265-270° (dec.), contains one methoxyl and one methylimino group, two active hydrogens and a lactone ring, opened by alkali and re-formed on acidification. In a later paper the same authors describe the isolation of benzoylheteratisine, C29H3,03N, m.p. 213-4°, [a]jf° + 73° (EtOH), which yields a hydrochloride, m.p. 218-221° (dec.), and is hydrolysed to benzoic acid and heteratisine the latter they suggest may not exist naturally in the plant but may be produced from benzoylheteratisine during extraction. 

A solution of 21 g (0.15 mole) of perbenzoic acid (Chapter 17, Section II) in 250 ml of chloroform is prepared in a 500-ml round-bottom flask. Styrene (15 g, 0.145 mole) is added, and the solution is maintained at 0° for 24 hours with frequent shaking during the first hour. At the end of the reaction period, only the slight excess of perbenzoic acid remains. The benzoic acid is extracted from the reaction mixture by washing several times with 10% sodium hydroxide solution. The solution is then washed with water and dried over anhydrous sodium sulfate. Fractional distillation gives 24-26 g (69-75%) of 1,2-epoxyethylbenzene, bp 101 /40 mm. 

A mixture of 10 g of 4-(2, 4 -difluorophenyl)-phenol and 27.2 g of potassium carbonate is exposed to carbon dioxide at 1,300 psi and 175°C. The dark mass obtained from this car-donation is then dissolved in 300 ml of water and 200 ml of methylene chloride and the two layers separated. The water layer is then extracted with 100 ml of methylene chloride and then acidified with 2.5 N hydrochloric acid. This mixture is then filtered and the cake dried in vacuo to yield 5.32 g of the crude product. The crude product is then recrystallized from benzene-methanol. An additional crystallization of this semipure material from benzene-methanol yields analytically pure 2-hydroxy-5-(2, 4 -difluorophenyl)-benzoic acid (MP 210°-211°C). 

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