Residual extraction

Cool the flask in ice, acidify with 10 ml. of cold 1 1-hydro-chloric acid and distil under reduced pressure (water pump) until most of the alcohol is removed. Add water to the residue, extract several times with ether, wash the combined ethereal extracts with N ammonia solution until a test portion gives no precipitate upon acidification. Extract the combined alkahne solutions once with a fresh portion of ether, and add the aqueous solution to an excess of dilute hydrochloric acid the final mixture should still be acidic to Congo red. Collect the crystalhne half-ester by filtration at the pump, wash it with water and dry at 100°. The yield is 14-5 g., m.p. 122-125°. Recrystallise by dissolving in about 40 ml. of warm benzene and adding an equal volume of petroleum ether (b.p. 40- 60°) 13 -5 g. of the colourless half-ester, m.p. 125-126°, are obtained. 

Pyronin Y [3,6-bis(dimethylamino)xanthylium chloride] [92-32-0] M 302.8, m 250-260, Cl 45005, Xmax 522nm, pKesi Commercial material contained a large quantity of zinc. Purified by dissolving Ig in 50mL of hot water containing 5g NaEDTA. Cooled to 0, filtered, evapd to dryness and the residue extracted with EtOH. The soln was evaporated to 5-lOmL, filtered, and the dye pptd by addition of excess dry diethyl ether. It was centrifuged and the crystals were washed with dry ether. The procedure was repeated, then the product was dissolved in CHCI3, filtered and evapd. The dye was stored in a vacuum. 

The distillate is extracted with five 50-cc. portions of benzene, and the benzene solution is dried thoroughly with powdered sodium hydroxide and distilled (Note 5). Most of the amine distfls at 184-186°, but the fraction distilling at 180-190° is sufficiently pure for most purposes (Note 6). The yield of this fraction is 80-88 g. By combining the benzene fore-run with the distillation residue, extracting with dilute acid, and recovering the amine as above, an additional 10-12 g. of material can be obtained (Note 7), making the total yield po-ioo g. (60-66 per cent of the theoretical amount based on the acetophenone taken) (Note 8). 

Sack has recently isolated a ketone from natural civet. The civet was boiled for some hours with alcoholic potash, the alcohol evaporated and the residue extracted, with ether. The residue left on evaporating the ether was distilled with steam to remove skatole, again extracted with ether, the ether evaporated and the residue dissolved in alcohol. The alcohol was evaporated, and the residual ketone purified by conversion into its semi-carbazone, from which it was regenerated. It has the formula CjjHggO, and its characters are as follows —... 

A mixture was made of L-tyrosine (18.1 g, 0.1 mol) benzoyl chloride (7.0 g, 0.05 mol) and 200 ml anhydrous THF. After stirring at reflux for 2 hours, the mixture was cooled to room temperature, and the precipitate of tyrosine hydrochloride filtered off (11 g, 46 meq. Cr). The THF was evaporated and the residue extracted with CCI4 (3 X 100 ml at reflux, discarded) and then dissolved in ethyl acetate (200 ml) filtering off insolubles. The ethyl acetate solution was evaporated to yield 13.2 g solid product, MP 159°-162°C (93%). The tyrosine was recovered (8 g) by neutralization with aqueous alkali, from the hydrochloride. 

The solution of the Grignard reagent prepared in (A) was cooled to 5° to 10°C and stirred while 22.7 g (0.11 mol) of dibenzo[a,e] cycloheptatrien-5-one was added in portions. After stirring for 1 hour during which time the reaction mixture was allowed to warm up to room temperature, the bulk of the tetrahydrofuran was distilled at 40° to 50°C under reduced pressure. Benzene, 150 ml, was added and the reaction mixture stirred and cooled in an ice-bath while water, 100 ml, was added gradually. The benzene layer was separated by decantation and the gelatinous residue extracted three times with 75 ml portions of boiling benzene. 

To a suspension of 12.0 grams of 3-methylflavone-8-carboxylic acid in 200 ml of anhydrous benzene Is added 10.0 grams of thionyl chloride. The mixture is refluxed for 2 hours during which the suspended solid goes into solution. The solvent is completely removed by distillation, the residue extracted with benzene and the extract evaporated to dryness. The product, 3-methylflavone-8-carboxylic acid chloride, is recrystallized from ligroin to give crystals melting at 155° to 156°C. 

The mixture is poured onto excess ice, acidified with concentrated hydrochloric acid, the ether layer sepatated and extracted with water (1 x 200 cc). The combined aqueous extracts are washed with ether (1 x 200 cc) basified with 0.880 ammonia and extracted with chloroform (3 x 350 cc) the extract is washed with water (2 x 100 cc), dried over sodium sulfate, evaporated, and the residue extracted with boiling light petroleum (BP 60° to 80°C 10 volumes), filtered hot and evaporated to dryness. The residue is recrystallized from alcohol to give a cream solid (119 g, 80%), Pi/IP 117° to 118°C. Recrystallization gives 1-(4-methylphenyl)-1-(2-pyridyl)-3-pyrrolidonopropan-1-ol, MP 119° to 120°C. 

To a —78 C solution of 23.1 mL (100 mmol) of triisopropyl borate and 8.15 mL (110 mmol) of 3-chloro-l-propene in 100 inL of dry THF is added dropwisc via a cannula over 0.5 h a solution of LDA (110 mmol prepared in 200 mL of THF from 110 mmol of diisopropylamine and 47.9 mL of 2.3 M butyllithium in hexane), This mixture is stirred for an additional 0.5 h at — 78 "C then a solution of 75.9 ntL of 2.9 M anhyd hydrogen chloride in diethyl ether is added and the mixture is allowed to warm to 25 °C. The mixture is concentrated in vacuo (20 Torr) and the residue extracted with three 100-mL portions of pentane, Filtration under nitrogen followed by distillation under reduced pressure provides 18.0 g (88%) of diisopropyl l-chloro-2-propenylboronate bp 95-96 "C/25 Torr. Transesterification of this intermediate with 1.3-propanediol provides the title compound in almost quantitative yield bp 110-112°C/20Torr. 

Figure 1. Schematic diagram showing a TRU-spec extraction chromatography method for separation of uranium, thorium, protactinium, and radium from a single rock aliquot. Further purification for each element is normally necessary for mass spectrometric analysis. Analysis of a single aliquot reduces sample size requirements and facilitates evaluation of uranium-series dating concordance for volcanic rocks and carbonates. For TIMS work where ionization is negatively influenced by the presence of residual extractant, inert beads are used to help remove dissolved extractant from the eluant.

Extraction Procedure. A flow chart of the isolation and identification procedure is presented in Figure 1. Field-grown rye ( Abruzzi, harvested at early flowering stage on March 24, 1983, from the Central Crops Research Station, Clayton, NC) was air-dried for 7 days. The tissue (150 g) was extracted with 3 L of distilled water for 10 hr with agitation. The extract was filtered through cheesecloth and then centrifuged at 28,000 x g for 20 min. The supernatant was reduced in volume to 300 ml jim vacuo at 50°C. Sixty ml of the concentrated aqueous extract was dried in vacuo, the residue extracted with 20 ml of methanol and filtered. The metha-nolic extract was stored at 0°C until use. 

Reduction of 2,2-bisf3 -nltro-4 -(4"-phenylsulfonylphenoxyl)phenyl1 propane. Compound 9, 200 mg (0.55 meg) was dissolved in a mixture of 30 mL of dichloromethane (DCM) and 30 mL of methanol and 240 mg of 10% palladium on charcoal was added. After purging the solution with argon for 30 min, 520 mg (13.6 mmol) of sodium borohydride was added portionwise over 10 min. The reaction mixture was stirred under argon for 1 hr before addition of 30 mL of DCM. The mixture was filtered, the filtrate evaporated, and the residue extracted with DCM. Evaporation of the extract yielded 140 mg (76.2%) of 2,2-... 

Figure 8.12 Mass chromatogram of m/z 453 of the organic residues extracted from a bowl recovered from Amarna. O, methyl moronate Q, methyl oleanonate U, methyl masticadie nonate W, methyl isomasticadienonate 1 4, unidentified compounds with a base peak at m/z 453. Reproduced from B. Stern, C. Heron, L. Corr, M. Serpico, j. Bourriau, Archaeometry, 45, 457 469. Copyright 2003, with permission from Blackwell...

Yakle GA, Cruse RM (1984) Effects of fresh and decomposing com plant residue extracts on com seedling development. Soil Sci Soc Am J 48 1143-1146 Young CC, Zhu Thoume LR, Waller GR (1989) Phytotoxic potential of soils and wheat straw in rice rotation cropping systems of subtropical Taiwan. Plant Soil 120 95-101 Yu JQ (2001) Autotoxic potential of cucurbit crops phenomenon, chemicals, mechanisms and means to overcome. J Crop Prod 4 335-348... 

Figure 11.4 Total ion current (TIC) chromatogram of lipid residue extracted from a potsherd of Early Neolithic date (Ecsegfalva, Hungary). Cx y F refer to fatty acids with carbon number (x) and number of unsaturations (y). Cx T refer to triacylglycerols with number of carbon atoms (x). P = plasticizer contamination. (Craig et al., 2007, 354 Figure 18.1, by permission.)...

Saltar and Paasivirta [155] have described a method for the analysis in soils of MCPA (4-chloro-2-methyl phenoxy acetic acid) and two of its main metabolites, 4-chloro-o-cresol and 6-chloromethyl catechol by gas chromatography of their pentafluorobenzyl derivatives (Fig. 9.12). After derivitization of the residue extract, a clean-up procedure was applied. The best recoveries of compounds from soil were obtained when the extraction was performed by shaking with ether-acetone-heptane-hexane (2 1 1 1) from acidified soil and when the clean-up was done by thin layer chromatography (Table 9.17). Detection limits were in the range 20-25ng absolute. 

Fig. 3.26. Typical elution HPLC profiles of MG residues extracted from (a) salmon spiked at 20 pg/kg LMG and MG each (b) residue-incurred salmon fillet (2.9 pg/kg). Analysis of the residue-incurred salmon was repeated using the LC-MS-MS system as shown in (c) the profile shows the monitoring of the m/z = 329.5 to m/z 313.3 fragmentation. The elution positions of MG, LMG and the internal standard brilliant green (BG) are indicated. Note BG is not detected in the m/z = 329.5 to m/z 313.3 trace (c) and its position is therefore depicted as an under broken arrow. Reprinted with permission from A. A. Bergwerft et al. [105],...

Cow feces (di sulfoton and 5 metabolites as total residue) Extraction with chloroform concentration then oxidation with m-chioroperbenzoi c acid clean-up by column chromatography GC/FPD 1ng/kga 74 Bowman and Beroza 1969... 

Mono(bromophenoxy)phenol (I). The mono(bromophenoxy)phenols required for the monomeric models were synthesized by two methods. Method A A mixture of pyridine (90mL), diol (60 mmol), dibromobenzene (56.4g, 240 mmol), anhydrous potassium carbonate (33.3g, 250 mmol) and cuprous iodide (1.62g, 9 mmol) was heated at reflux under nitrogen for 20h. After cooling to room temperature, the reaction mixture was acidified with IN HC1 and the product extracted with chloroform. The chloroform was evaporated and the residue extracted with 10% aq. NaOH. The aqueous phase was acidified, extracted with chloroform, and reduced in volume to an oil that was stirred with 20% aq NaOH to afford the sodium salt of the product. The salt was Isolated and dried to give a white solid. The solid was acidified to pH 1 in water, and the freed mono(bromophenoxy)phenol was washed with water and dried. C-H analysis for products was satisfactory. 

The supernatant was removed at - 30 °C, and the catalyst residue extracted once with cold n-octane. GC analysis indicated an 82% yield of 4a. As summarized in Fig. 3 (entry 1), the recovered 5a was used for four further cycles without deterioration in yield. Multiple runs could be similarly conducted with alcohols 2b-d, affording comparable yields of 4b-d (entries 2-4). A number of control experiments have been detailed elsewhere [33,34]. Also, since 2a,c,d, 3, and 4a-d are hquids at room temperature, these reactions... 

Methyl phenylethynyl telluride (typical procedure). To NaNH2 (from 6.0 g, 0.26 mol Na) in liquid NHj (250 mL) is added phenylacetylene (25 g, 0.25 mol) dropwise, and then Te powder (30 g, 0.24 mol) in small portions, stirring well for 30 min. Methyl iodide (36 g, 0.25 mol) is added over 20 min to the tellurolate solution. The NHj is then evaporated, the residue extracted with ether and the ether solntion washed with HjO and dried (MgS04). The residue is distilled under vacnum, giving the product (28 g (46%) b.p. 122-124°C/2 torr). 

Diacetoxylation of olefins with benzenetellurinic anhydride (typical procedure) To a solution of (PhTe0)20 (0.95 g, 2.1 mmol) in dry HOAc (15 mL) is added styrene (0.208 g, 2.0 mmol) in HOAc (4 mL) and 98% H2SO4 (0.020 g, 0.2 mmol) in HOAc (1 mL). The mixture is gently refluxed for 24 h, which turns red with deposition of a small amount of elemental tellurium. After removal of tellurium (0.071 g, 0.56 mmol) by fdtration, the solvent is evaporated, the residue extracted with ether and the ether extract dried (MgS04). Chromatography on Si02 gives the v/c-diacetate (0.363 g (82%)) and 1-phenylethyl acetate (0.029 g (9%)). 

To an orange solution of 11.78 g (25.9 mmol) of 1 (R1 = H) in 400 mL of THF under nitrogen at —78°C are added 25.1 mL (40.2 mmol) of butyllithium and the resulting dark-red mixture is stirred at this temperature for 3.5 h. Then 8.0 mL (63.1 mmol) of chlorotrimethylsilane, freshly distilled from calcium hydride, are added in one portion, the mixture stirred at —78 C for 1 h and then warmed to r.t. over 2 h. The solvent is removed and the residue extracted with three 20-mL portions of CH2C12. The combined extracts are filtered through alumina (grade V) to give, upon removal of the solvent, pure product yield 13.35 g (98%)28. 

A mixture of 1 (200 mg, 0.45 mmol) and spermidine 4b (380 mg, 1.1 mmol) in THE (10 mL) was reacted with NaBH(OEh)3 (2 equiv) at room temperature under an argon atmosphere. The reaction was monitored by TLC analysis. After the reaction was complete, the solvent was removed, the residue extracted with ethyl acetate, and then the combined organic extracts were dried over anhydrous Na2S04, before being concentrated. 

To a flask is added 15.0 gm (0.082 mole) of phenylethylcarbamyl chloride dissolved in 50 ml of benzene and 20 ml of absolute ethanol. Dry ammonia is passed through the solution until no more ammonium chloride is deposited. The solution is filtered, the filtrate evaporated, and the syrupy residue extracted with benzene. The filtered extract is evaporated again to give a faintly brown residue which crystallizes in plates to give 13.5 gm (100%), m.p. 60°C (after drying under reduced pressure for 24 hr). 

F. C. Mathers and C. G. Schluderberg 124 prepared indium iodate, In(I03)3, by mixing soln. of indium trichloride and potassium iodate. The precipitate is amorphous. The mixture was evaporated to dryness on a water-bath the residue extracted on a Gooch s crucible with warm water and dried in vacuo over sulphuric acid. The mass was dissolved in boiling nitric acid (1 10), and on evaporation white crystals of indium iodate were formed. 100 grms. of water at 20° dissolve 0 067 grm., and 100 grms. of nitric acid (1 5) at 80° dissolve 0 67 grm. of the salt. It also dissolves in dil. sulphuric or hydrochloric acid. The soln. in the last-named add decomposes with the liberation of chlorine. The crystals decompose with the evolution of iodine when heated by a free flame and explode if touched with a red-hot iron wire. 

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