Solvent extraction with ethyl acetate

Soil Ultrasonic solvent extraction with ethyl acetate and unltracentrifuged GC/FID 0.1 g/mL 73.3 Cartwright et al. 2000... 

S g of ethyl glycinate hydrochloride were dissolved in 400 cc of ethanol and 33.5 g of salicylic aldehyde were added. It is refluxed for half an hour and cooled. 38 cc of triethylamlne and 25 g of Raney nickel are then added whereafter hydrogenation is carried out at room temperature and under atmospheric pressure. After hydrogen adsorption was complete, the mixture was filtered and the alcohol evaporated off. The residue was taken up with acidified water, extracted with ether to eliminate part of the by-products, consisting mainly of o-cresol, then made alkaline with ammonia and extracted with ethyl acetate. The solvent was removed in vacuo and the residue crystallized from ether/petroleum ether. 36.7 g of o-hydroxybenzyl-aminoacetlc acid ethyl ester melting at 47°C are obtained. 

To two liters of a culture so prepared there is added under sterile conditions a solution of 500 mg of 17a-methyl-testosterone in 15 cc of acetone. Shaking is carried out for 3 days at 27°C, the mycellium then filtered off with suction, washed with water and ethyl acetate and the combined filtrates extracted with ethyl acetate. The extraction residue obtained after evaporation of the solvent is dissolved in a little acetone. On addition of ether, the 1-dehydro-17a-methyl-testosterone is obtained in compact crystals. MP 163° to 164°C. 

The resulting mixture does not crystalize and is converted into a mixture of oximes by treatment of a solution of the mixture in 20 ml of ethanol with a solution of 1.8 g of hydroxylamine sulfate in 3 ml of water. 1.B g of sodium acetate In 5 ml of water is added, and the mixture is refluxed for 5 hours, then extracted with ethyl acetate, and the ethyl acetate solution is washed with a saturated aqueous sodium chloride solution and dried over Sodium sulfate. After evaporating the solvent, the residue is triturated with warm ether and 1.1 g of a crystalline oxime is obtained, MP 16B° to 171°C. 

The solvent was evaporated to yield a colorless solid residue, which was taken up In ethyl acetate-ice water. The two layers were separated and the aqueous layer was extracted with ethyl acetate. The combined organic layers were washed with water, saturated sodium chloride solution and filtered through anhydrous sodium sulfate. The solvent was evaporated to yield 1.20 grams of light tan crystals, MP 151° to 155°C, ultraviolet maximum at 224 mp (E = 4,095). Two recrystallizations from ethanol afforded 1st crop, 0.619 grams (62%) of colorless crystals (dried at 120°C in vacuo for 17 hours), (VIP 232.8° to 238.0°C, ultraviolet maximum at 224 mp (E = 4,840) 2nd crop, 0.142 gram (14%) of colorless crystals, MP 234° to 242°C. 

To a stirred solution of (1.5 mmol) of LDA in 3.5 mL of THF/hcxane (60 40) at — 78 C under a nitrogen atmosphere is added 198 mg (1.5 mmol) terf-butyl propanoate in 1.5 mL of HMPA. After 30 min 169 mg (1.5 mmol) of potassium rm-butoxide are added and the mixture is stirred for 10 min. Then 133 mg (0.5 mmol) of ethyl 6-iodo-2-hcxcnoatc in 1.5 mL of TI1F arc added and the mixture is stirred for an additional 0.5 h at — 78 C. The reaction is quenched by adding sat. aq NH4C1. Extraction with ethyl acetate, drying over Na,S04 followed by evaporation of the solvent and short-path distillation gives the adduct yield 135 mg (100%). 

In order to ascertain that the NDELA formation does not occur as a result of trapping of the smoke or during the analysis, we added diethanolamine to tobacco prior to extraction with ethyl acetate in the presence of ascorbic acid. The control value for NDELA was 121 ppb and the experiment with 5.5 iqg diethanolamine addition yielded 113 ppb NDELA. For control of the smoke analysis we added 5.5 mg of DELA in the solvent trap and smoked cigarettes known to be free of DELA. Analysis of the trapped material showed no significant quantities of NDELA, so that artifactual formation of this nitrosamine during smoke collection and analysis can be ruled out. 

Almost all anilides in water samples are directly extracted with ethyl acetate or dichloromethane, and the method of multi-residue analysis can be applied to the water samples. However, in the case of naproanilide, the water sample is extracted with an organic solvent under acidic conditions. A 5-mL volume of 1N hydrochloric acid and 50 mL of ethyl acetate-n-hexane (1 1, v/v) are added to 200 mL of water sample, and the mixed solution is shaken vigorously using a mechanical shaker for... 

Bispyribac-sodium is recovered as the free acid, bispyribac, from plant material and soil by acetonitrile-water (4 1, v/v) solvent extraction. After filtration, the acetoni-tirile is evaporated under reduced pressure. The aqueous residue is dissolved in buffer solution (pH 7.4) and washed with ethyl acetate to separate the impurities from the extract. Then the solution is acidified and extracted with ethyl acetate. The ethyl acetate is evaporated. The residue is methylated with trimethylsilyldiazomethane. 

Celite or hyflo super cell (20 g) was added to the suspension which was then filtered through a pad of hyflo in a wide-sinter funnel the pad was washed with water (100 mL). The filtrate was saturated with sodium chloride and then extracted with ethyl acetate (5 x 500 mL). The combined extracts were dried over magnesium sulfate, filtered and the solvent was removed under reduced pressure to afford a pale viscous oil. 

General procedure for the preparation of 4-functionalized-l-alkyl-3-methylindoles (2) A solution of the starting amine 1 (2 mmol) in THF (15 mL) was treated with /BuLi (7 mmol, 3.5 equiv) at -110°C. The reaction mixture was stirred at this temperature for 15 min and then at -40°C for 3 h. The reaction mixture was re-cooled to -78°C and the electrophile (3 mmol) was added. The reaction mixture was stirred overnight at room temperature, then hydrolyzed with water, and extracted with ethyl acetate (3 x 20 mL). The combined organic layers were dried over anhydrous Na2S04. The solvent was removed under vacuum and the residue was purified by flash column chromatography (hexane/ethyl acetate) and/or by recrystallization to afford products 2. 

The concentration of acrylic acid by extraction with ethyl acetate is a rather different illustration of this technique. As shown in Figure 13.4, the dilute acrylic acid solution of concentration about 20 per cent is fed to the top of the extraction column 1, the ethyl acetate solvent being fed in at the base. The acetate containing the dissolved acrylic acid and water leaves from the top and is fed to the distillation column 2, where the acetate is removed as an azeotrope with water and the dry acrylic acid is recovered as product from the bottom. 

Domino-Heck Reactions-General Procedure 5.6 mg (25 pmol) of palladium(II) acetate and 55 pmol of the arsine ligand were dissolved in 3 ml of dry dimethyl formamide and the solution was stirred at 65°C (40°C for trimethylsilylacetylene) for 15 mitt Then, 127 mg (1.35 mmol) N-Benzoyl-2-azabicyclo[2.2.1]hept-5-en-3-one, 1 mmol of the aryl compound. Four hundred and eighty-eight microliters (3.50 mmol) of triethylamine, and 3.00 mmol of the phenylacetylene (or silylmethyl-acetylene) were added rapidly in one portion. The mixture was heated at the same temperature for 24 h. After cooling down to room temperature 50 ml of brine were added, the reaction mixture was extracted with ethyl acetate and dried over MgSO. The solvent was evaporated, the residue purified by column chromatography (n-Hexan-Ethyl acetate 4 1). 

The culmre solution was extracted with ethyl acetate (3 x 100 mL). Combined extracts were washed once with brine and dried with anhydrous Na2S04. The solvent was removed on a rotary evaporator and the residue was purified by flash chromatography over silica gel to afford the title compound as white crystals (36 mg, 65 % isolated yield). 

Crude GSE can be separated into distinct components from monomer-rich to oligomer- and polymer-rich fractions by solvent extraction followed by chromatography on Toyopearl resin. The pre-fractionation of the tannin crude extract by liquid-liquid extraction with ethyl acetate fractionates the monomers into the organic phase and improves the subsequent fractionation of oligomers and polymers on Toyopearl HW 40 resin. This fractionation technique is easy to operate and... 

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