Solvent extraction with diethyl ether

Hydrogenolvsis. This methodology involves the reaction of Vitride (sodium bis(2-methoxyethoxy)aluminum hydride with the lysoalkenyletherphos-phatidylcholine as outlined for the saturated ethers earlier in this chapter. This leads to the formation of 1-O-alkenylglycerol in very good yields. This latter material can be recovered from the reaction mixture by solvent extraction with diethyl ether. The isolated alkenylglycerol can be subjected to the following reactions. 

Phenol materials in apple juice have been recovered with methanol from polyamide columns (at40 C) after elution of sugars and acids with water (10). Column chromatography on alumina has been used as a first step in the identification of phenolic material from Colchicum lusitanum (II). Extrelut 20 columns have been employed in the enrichment of phenolic acids in urine from the metabolism of catecholamines (12). And in the determination of phenol and o-cresol in fresh urine, solvent extraction with diethyl ether or dipropyl ether has been used following a preliminary hydrolysis with 60% perchloric acid (13). 

As shown in Table 8, the acidic fraction (sample D in Table 6) obtained from the residue after extraction by SDE-SV was a good source of additional information, particularly about polar aroma compounds. They were isolated from the SDE residue by direct solvent extraction with diethyl ether, purified by extraction with... 

Fig. 7.2 Chromatogram of acidic metabolites extracted from the urine of a normal child using DEAE-Sephadex and re-extraction with solvents after ethoxime formation and freeze-drying by reconstitution in water, acidification with hydrochloric acid, saturation with sodium chloride, and solvent extraction with diethyl ether (three times) and ethyl acetate (three times), evaporation of the solvents from the combined extracts using dry nitrogen and trimethylsilylation using the minimum quantity of BSTFA. Separated on 10 per cent OV-101 on HP Chromosorb W (80-100 mesh) by temperature programming from 110°C to 285°C at 4°C min with an initial 5 min isothermal delay. Peak identifications are 1, phenol plus lactate 2, glycollate 3, cresol 4, 3-hydroxyisovalerate 5, benzoate 6, phosphate 7, succinate 8, 3-methyladipate 9, 3-hydroxy-3-methyl-glutarate 10, 4-hydroxyphenylacetate 11, homovanillate plus some aconitate 12, hippurate 13, citrate 14, vanilmandelate 15, n-tetracosane (standard) 16, n-hexacosane (standard).

A solution of 0.21 mol of butyllithium in about 140 ml of hexane (note 1) was cooled below -40°C and 90 ml of dry THF ivere run in. Subsequently a cold (< -20 C) solution of 0.25 nol of propyne in 20 ml of dry THF was added with cooling below -20°C and a white precipitate was formed. A solution of 0.10 mol of anhydrous (note 2) lithium bromide in 30 ml of THF was added, followed by 0.20 mol of freshly distilled cyclopentanone or cyclohexanone, all at -30°C. The precipitate had disappeared almost completely after 20 min. The cooling bath was then removed and when the temperature had reached 0°C, the mixture was hydrolyzed by addition of 100 ml of a solution of 20 g of NHi,Cl in water. After shaking and separation of the layers four extractions with diethyl ether were carried out. The extracts were dried over magnesium sulfate and the solvents removed by evaporation in a water--pump vacuum. Careful distillation of the remaining liquids afforded the following... 

To a mixture of 25 ml of water and 3 ml of 95% sulfuric acid were added 40 ml of DMSO. The mixture was cooled to 10°C and 0.20 mol of l-ethoxy-l,4-hexadiyne (see Chapter III, Exp. 51) was added with vigorous stirring in 15 min. During this addition, which was exothermic, the temperature of the mixture was kept between 20 and 25 0. After the addition stirring was continued for 30 min at 3S C, then 150 ml of water were added and six extractions with diethyl ether were carried out. The combined extracts were washed with water and dried over magnesium sulfate. Evaporation of the solvent in a water-pump vacuum, followed by distillation through a 25-cm... 

The common impurities found in amines are nitro compounds (if prepared by reduction), the corresponding halides (if prepared from them) and the corresponding carbamate salts. Amines are dissolved in aqueous acid, the pH of the solution being at least three units below the pKg value of the base to ensure almost complete formation of the cation. They are extracted with diethyl ether to remove neutral impurities and to decompose the carbamate salts. The solution is then made strongly alkaline and the amines that separate are extracted into a suitable solvent (ether or toluene) or steam distilled. The latter process removes coloured impurities. Note that chloroform cannot be used as a solvent for primary amines because, in the presence of alkali, poisonous carbylamines (isocyanides) are formed. However, chloroform is a useful solvent for the extraction of heterocyclic bases. In this case it has the added advantage that while the extract is being freed from the chloroform most of the moisture is removed with the solvent. 

To a stirred solution of 2.0 mmol of LDA in 3.3 mL of a 60 40 mixture of THF/hexane at — 78 °C under a nitrogen atmosphere is added 264 mg (2.0 mmol) of tert-butyl propanoatc in 2 mL of THF. After 30 min stirring a solution of 168 mg (1.5 mmol) of ethyl (t)-2-butenoalein 1.5 mL of THE is added and the mixture is stirred for an additional hour at — 78 °C. The reaction is quenched by addition of sat. NH4C1. Extraction with diethyl ether, drying over NiiCl followed by evaporation of the solvent and short path distillation gives the adduct yield 378 mg (1.2 mmol, 84%). 

To a solution of 5.1 g (20 mmol) 6-(l-methyl-2-nitroethyl)-l-(4-morpholinyl)-l-cyclohexene in 10 mL of ethanol are added, with cooling, 50 mL of 10% aq hydrochloric acid. The mixture is stood at r.t. for 12 h, the solvent is removed under reduced pressure and the residue is extracted with diethyl ether. The ethereal extract is evaporated leaving the crude title compound as a brown oil yield 3.0 g (80%) which is purified by distillation pale yellow oil, bp 128- 130°C/0.8 Torr nji,5 1.4808. The product is unstable and darkens after a short period of storage. 

Solvent extraction. Extraction of neonicotinoid insecticides from water is a simple process involving saturation with sodium chloride and extraction with diethyl ether, dichloromethane or ethyl acetate. This extraction procedure will allow the simultaneous extraction of all neonicotinoids. 

Indole 73 can be selectively alkylated [110] (Scheme 8.75) by benzyl bromide to give 74 in high yield (>90%) when the reactants were mixed with l-butyl-3-methylimi-dazolium hexafluorophosphate ([bmim][PF6]) as polar solvent and the reaction was performed with brief (1 min) microwave irradiation at 180 °C. Product 74 was fully extracted with diethyl ether and [bmim][PF6] was reused in another cycle of synthesis. 

The solvent was removed by using a rotary evaporator. The solution was dissolved in a saturated solution of NH4C1 and extracted with diethyl ether. After the solution was dried with magnesium sulfate, the diethyl ether was removed by using a rotary evaporator. 

After addition of saturated sodium hydrogen carbonate solution (20 mL) the organic layer was separated and the aqueous layer extracted with diethyl ether (3 x 70 mL). The combined organic layers were dried over magnesium sulfate, filtrated and the solvent removed using a rotatory evaporator to give a yellow oil. 

Hexafluoro-2-(4-fluorophenyl)-2-propyl acrylate (la) and hexafluoro-2-(4-fluorophenyl)-2-propyl methacrylate (lb)7 were prepared by gradually adding a solution of 0.06 mol of acryloyl or methacryloyl chloride, respectively, in 20 ml of tetrahydrofuran (THF), to a cooled solution of 0.04 mol of HFAF in 50 ml of THF containing 0.06 mol oftriethylamine. The mixture was stirred for 10-12 h at room temperature it then was poured into 200ml of water, and the new product was extracted with diethyl ether. After the diethyl ether was evaporated, the crude product was purified by column chromatography using a mixture of hexane and dichloromethane (1 1 by volume) as the elution solvent. Distillation afforded la, b.p. 72-74°C/10"3 mm Hg, and lb, b.p. 48-52oC/103 mm Hg. 

Consequently, the red-complex is extracted with either solvents possessing donor oxygen atoms, such as 3-methyl butanol. However, Mo (VI) may also be extracted with diethyl ether-an oxygenated solvent, because it yields the maximum percentage extractive with 7.0 M NH4 SCN as could be seen from the following Table 27.2. 

The advantages of using ionic liquids as solvents for Diels-Alder reactions are exemplified by the scandium triflate catalysed reactions [14] in [bmim][PFg], [bmim][SbF6] and [bmim][OTf] for the reaction shown in Scheme 7.6. Whilst the nature of the anion seems to have little effect, all these solvents give rate enhancements for a range of Diels-Alder reactions compared to when the reactions are carried out in dichloromethane (DCM). Also, the selectivity towards the endo product is higher than in conventional solvents. As well as the enhanced rates and selectivities, the products can also be removed by extraction with diethyl ether and the ionic liquid and catalyst can immediately be reused. Experiments... 

The effect of saponification on the concentration of carotenoids in fatty foods has also been investigated by RP-HPLC. Sausages containing 5.6 per cent powdered paprika were extracted exhaustively with chloroform-methanol (2 1, v/v). The extracting solvent contained 0.01 per cent butylated hydroxyanisole (BHA). An aliquot of the combined extracts was evaporated to dryness and saponified at 50°C for 5min with 10 per cent KOH in methanol in the presence of 0.01 per cent BHA. Free carotenoid pigments were extracted with diethyl ether, washed with water, dried over anhydrous NajSC and evaporated under... 

TBAF (1 mmol, 1 M in THF) was added to the combined organic extracts and the resulting solution was stirred for 3 h. The solution was then washed once with water and once with brine, back-extracted with diethyl ether, and the organic layer was dried over anhydrous MgS04. The solvent was then removed in vacuo and the product was purified by silica column chromatography. In order to determine the ee, the product was converted into the corresponding (R,R)-2,3-dimethylethylene ketal and then analyzed by GC analysis (Chiraldex G-TA) for the diastereomeric ketals. 

Isolation of toxins. The digestive glands of shellfish were extracted with acetone at room temperature. After removal of the acetone by evaporation, the aqueous suspension was extracted with diethyl ether. The ether soluble residue was successively chromatographed twice over silicic acid columns with following solvents benzene to benzene-methanol (9 1), and diethyl ether to diethyl ether-methanol (1 1). To avoid degradation of dinophysistoxin-3 by contaminant acid, the silicic acid was washed with dilute sodium hydroxide solution and then with water prior to activation at 110 C. Toxic residue obtained in the second eluates was separated into two fractions... 

The easiest way to 10 goes via the synthesis of KDNM (see Section n.C). Acidification of an aqueous solution of KDNM, which should be buffered with H3PO4 (pH = 6.5), followed by low-temperature extraction with diethyl ether, gives the monomeric emerald-green nitrosolic acid 10 dissolved in the ether phase. Slow removal of the solvent yields the yellowish dimeric form of 10. The acid (10) is only poorly characterized. It is known to slowly decompose into HCN and HNO2 in basic solution (decomposition of the anion DNM), while the free acid (10) rapidly decomposes to give fuhninic acid, HCNO and hyponitrous acid, HON=NOH. It should be noted that both the free acid and its metal DNM salts are highly explosive. 

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