Extraction diethyl ether

Vote 2. With diethyl ether continuous extraction has to be performed. 

To 75 ml of a 50 aqueous solution of KOH were added 0.25 mol of chloroform, 0.2 g of triethylbenzylammonium chloride and 0.10 mol of freshly distilled 1,2-cyclononadiene (see this chapter, Exp. 20) and the mixture was stirred vigorously for 10-12 h. Water (200 ml) was added and the products were extracted with diethyl ether. The extracts were dried over magnesium sulfate, concentrated in a water-pump vacuum and the residue was distilled through a short Vigreux column. The adduct, b.p. 80 C/0.15 mmHg, n j 1.5300, was obtained in 75% yield. 

In the flask were placed a solution of 7 g of anhydrous LiBr in 50 ml of dry THF, 0.40 mol of the allenic bromide (see Chapter VI, Exp. 31) and 0.50 mol of finely powdered copper(I) cyanide. The mixture was swirled by hand and the temperature rose in about 15 min to 60°C. It was kept between 55 and 60°C by occasional cooling in a water-bath. When the exothermic reaction had subsided, the flask was warmed for an additional 30 min at 55-60°C and the brown solution was then poured into a vigorously stirred solution of 30 g of NaCN and 100 g of NH,C1 in 300 ml of water, to which 150 ml of diethyl ether had been added. During this operation the temperature was kept below 20 c. The reaction flask was subsequently rinsed with the NaCN solution. After separation of the layers the aqueous layer was extracted with ether. The extracts were dried over magnesium sulfate and then concentrated... 

Sodium hydride (9.3 g, 0.22 mol) was washed with petroleum ether and DMSO (200 ml) was added and the mixture was heated to 100°C. A solution of diethyl malonate (35.2 g, 0.22mol) in DMSO (50 ml) was then added and stirred for 10 min to give a clear solution. A solution of 4-bromo-3-nitrobenzophenone (30.6 g, 0.10 mol) in DMSO (100 ml) was added and the resulting dark solution kept at 100 C for 1 h. The solution was poured into water (3 1) and extracted (2x) with ether. The extract was washed with water, dried (NajSOj and concentrated in vacuo to give an oil which crystallized. The solid was recrystallized from isopropyl alcohol to give 35.4 g (92% yield) of the product. 

Liquid carboxylic acids are first freed from neutral and basic impurities by dissolving them in aqueous alkali and extracting with diethyl ether. (The pH of the solution should be at least three units above the pKg of the acid, see pK in Chapter 1). The aqueous phase is then acidified to a pH at least three units below the pK of the acid and again extracted with ether. The extract is dried with magnesium sulfate or sodium sulfate and the ether is distilled off The acid is fractionally distilled through an efficient column. It can be further purified by... 

Chloroacetone [78-95-5] M 92.5, b 119 /763mm, d 1.15. Dissolved in water and shaken repeatedly with small amounts of diethyl ether which extracts, preferentially, 1,1-dichloroacetone present as an impurity. The chloroacetone was then extracted from the aqueous phase using a large amount of diethyl ether, and distd at slightly reduced pressure. It was dried with CaCl2 and stored at Dry-ice temperature. Alternatively, it was stood with CaS04, distd and stored over CaS04. LACHRYMATORY. 

The two compounds were dissolved in diethyl ether by extracting the acidic layer three times with successive 500 ml portions of diethyl ether. The combined ether extracts were dried over anhydrous magnesium sulfate and filtered, and the ether was removed by evaporation in vacuo. A residue consisting of 400 g of a mixture of o-chlorophenyl ethylene-/3-bromohydrin and o-chlorophenyl ethylene oxide was obtained. 

To the mixture of 85.5 g ethyl a-(3chloro-4.aminophenyl)-propionate hydrochloride, 142 g sodium carbonate and 600 ml dimethyl formamide, 107 g 1,4room temperature. The mixture is filtered, the filtrate evaporated in vacuo, the residue is triturated with hexane, the mixture filtered, the residue washed with petroleum ether and the filtrate evaporated. The residue is combined with 280 ml 25% aqueous sodium hydroxide and the mixture refluxed for 8 hours. After cooling, it is diluted with water, washed with diethyl ether, the pH adjusted to 5 to 5.2 with hydrochloric acid and extracted with diethyl ether. The extract is dried, filtered, evaporated and the residue crystallized from benzene-hexane, to yield the a-(3-chloro-4-pyrrolinophenyl)-propionic acid melting at 94°C to 96°C. 

To a —78 °C solution of (4/C5/ )-2-[(.S )-l-chloro-2-propcnyl]-4,5-dicyclohcxyl-l, 3,2-dioxaborolanc (6) (theoretically 2.0 mmol) in THF are added 0.20 mL (2.0 mmol) of benzaldehydc. The mixture is allowed to reach r.t. overnight and is then treated with 0.30 g (2.0 mmol) of triethanolamine. After stirring for 3 h, 15 mL of sat. aq NH4C1 are added. The phases are separated and the aqueous phase is extracted with three 20-mL portions of diethyl ether. The combined extracts are dried over MgS04 and concentrated. The oily residue is purified by flash chromatography (silica gel, petroleum ether/diethyl ether 6 1) yield 0.26 g (79%) >99% ee [capillary GC of the carbamates obtained with (5 )-(l-isoCyanoethyl)benzene],... 

The carotenoid extract obtained by extraction of fresh food with a water-soluble solvent contains large amounts of water from the sample. In order to remove the water and solvent, in the case of acetone, carotenoids are transferred to petroleum ether, diethyl ether, or a mixture by adding small portions of the solvent extract and a large amount of water in a separatory funnel. The remaining traces of water can be removed either by addition of anhydrous Na2S04 or ethanol to form the azeotropic mixture. 

Glycosides can be hydrolyzed by taking the extract to dryness and treating the dry residues with 7.5% hydrochloric acid under reflux for 30 min. The freed aglycones can then be recovered by serial extraction with portions of diethyl ether. The extracted aglycones are then redissolved in a small volume of a suitable solvent, usually acetone or methanol. 

In 1965 Seshardri et al. described the isolation of an unknown terpenoid acid B obtained from the lichens of Lobaria retigera in the western Himalayas [8]. (Note that this annotation bears no relation to the subsequent nomenclature later defined by Corey and Shibata.) Four collections had been made in the summer of 1962 from under the Rutba plants in the Valley of Flowers (12,500 feet) and on the way to Hemkund Lokpal (13,500 feet) and from underneath rocks and from pine trees in Ganghariya (10,000 feet). The samples were subjected to a series of increasingly polar extractions (petroleum ether, diethyl ether, acetone). The unknown terpenoid acid B was present in all petroleum ether extracts, except that of the sample obtained from the Valley of Flowers, in compositions ranging from 0.47 % to... 

Normal-phase TLC has been employed for the separation of two new flavans in the extract of the undergorund tubers of Cyperus conglomeratus Rottb. (family Cyperaceae). The underground tubes were dried, ground and were extracted with with petroleum ether diethyl ether-methanol (1 1 1, v/v) for 24 h at ambient temperature. The extract was defatted with cold methanol. The components of the extract were preliminarily separated by traditional column chromatography followed by GC/MS and TLC. New flavans (5-hydroxy-7,3, 5 -trimethoxyflavan and 5,7-hydroxy-3, 5 -dimethoxyflavan) were separated on silica TLC layers using petroleum ether-diethyl ether (1 3, v/v) with the RF values of 0.50 and 0.37 for dimethoxy and trimethoxy derivatives, respectively [115]. 

A solution of LDA is prepared by the addition of 12 mmol of 1.6 M butyllithium in hexane to a stirred solution of 1.5 g (15 mmol) of diisopropylaminc in 15 mL of THF at 0°C, then cooled to —78 °C. A solution of 10 mmol of the benzyloxy boronic ester and 10-17 g (60-100 mmol) of dibromomethane is stirred at — 78 °C during dropwise addition of the LDA solution via a cannula. The solvent is distilled at <0.75 Torr <0 °C. The solid residue of borate complex is cooled to — 78 CC and treated with a 0.5-0.7 M solution of anhyd zinc chloride (Section 1.1.2.1.1.1.) [(1 On + 8) mmol, where n is the number of benzyloxy groups in the boronic ester] in THF. The mixture is stirred for 16-20 h at 20-25 °C. An equal volume of petroleum ether (bp 30-60 °C) is added, followed by 100 mL of sat. aq NH4C1. The aqueous phase is further extracted with 4 1 petroleum cthcr/diethyl ether, and the combined organic phase is filtered through a 5-cm column of MgS04 with the aid of additional petroleum ether/diethyl ether. After concentration, the residue of labile a-bromo boronic ester should be used promptly in the next step. 

Ether (diethyl) soluble materials are extracted from explosive mixtures using a Wiley-Richardson Extraction Assembly, ASTM, represented in Fig S-31505, p486 of E-H. Sargent Co catalog (See our Fig 1). An alundum crucible is used in place of extraction cup S 3l6l5 or S-31625. If elemental sulfur is present, a 2nd extraction is made with CS 2... 

Condition A Air, water, ethyl alcohol, impurity from extraction solvent (observed when the gas chromatograph is set at high sensitivity), diethyl ether, and extraction solvent (MEK/sec.-butyl alcohol). See Fig. 1, If acetone is present, it will elude at approximately the same retention time as the impurity from the extraction solvent. 

When appreciable amounts of lipids, chlorophylls, or unwanted polyphenols are suspected to be present in anthocyanin-containing extracts, these materials may be removed by washing with petroleum ether, ethyl ether, diethyl ether, or ethyl acetate (Jackman and Smith, 1996). 

The extraction of chlorophylls and carotenoids from water-containing plant materials requires polar solvents, such as acetone, methanol, or ethanol, that can take up water. These extracts must then be transferred to a solvent such as diethyl ether in order to be stored stably. Samples with very high water content, such as juices and macerated plant material, are usually freeze-dried first, and can then be extracted directly with diethyl ether. After extraction, solutions are clarified and diluted to an appropriate volume to measure chlorophyll content by UV-VIS spectrophotometry. Absorption coefficients and equations needed for quantitative determination are given in unitf4.3. 

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