Soxhlet apparatus

For extraction purposes, a Soxhlet apparatus (Fig. 23(H)) can be inserted between a flask of boiling solvent and the reflux condenser A above. This apparatus is similar in design to that shown in Fig. 19, p. 3b in the type shown in Fig. 23(H) the hot extract continuously overflows through the side- tube into the boiling solvent below, but the syphon type shown in Fig. 19 is also available. 

Solids by solvents. The various forms of Soxhlet apparatus illus trated in Section 11,44 can be purchased with ground glass joints. A simplified form, in which the fragile side tubes are absent, is shown in Fig. II, 58, 1. The material to be extracted, if of granular form, may rest upon a sintered glass disc or upon a removable septum ... 

If the outlet of the siphon tube at the bottom of the Soxhlet apparatus is well plugged with cotton wool so that no finely-divided bariuna hydroxide can pass into the flask, the barium hydroxide may be placed directly into the extractor until the latter is three-quarters full the remaining space is filled with glass wool. 

The experimental conditions for conducting the above reaction in the presence of dimethylformamide as a solvent are as follows. In a 250 ml. three-necked flask, equipped with a reflux condenser and a tantalum wire Hershberg-type stirrer, place 20 g. of o-chloronitrobenzene and 100 ml. of diinethylform-amide (dried over anhydrous calcium sulphate). Heat the solution to reflux and add 20 g. of activated copper bronze in one portion. Heat under reflux for 4 hours, add another 20 g. portion of copper powder, and continue refluxing for a second 4-hour period. Allow to cool, pour the reaction mixture into 2 litres of water, and filter with suction. Extract the solids with three 200 ml. portions of boiling ethanol alternatively, use 300 ml. of ethanol in a Soxhlet apparatus. Isolate the 2 2- dinitrodiphenyl from the alcoholic extracts as described above the 3ueld of product, m.p. 124-125°, is 11 - 5 g. 

The experimental details for mono-M-propylanillne are as follows. Reflux a mixture of 230 g. of aniline and 123 g. of n-propyl bromide for 8-10 hours. Allow to cool, render the mixture alkafine, and add a solution of 150 g. of zinc chloride in 150 g. of water. Cool the mixture and stir after 12 hours, filter at the pump and drain well. Extract the thick paste several times with boiling light petroleum, b.p. 60-80° (it is best to use a Soxhlet apparatus), wash the combined extracts successively with water and dilute ammonia solution, and then dry over anhydrous potassium carbonate or anhydrous magnesium sulphate. Remove the solvent on a water bath, and distil the residue from a Claisen flask with fractionating side arm (well lagged). Collect the n-propyl-aniline at 218-220° the yield is 80 g. Treat the pasty solid zincichloride with an excess of. sodium hydroxide solution and steam distil 130 g. of pure aniline are recovered. 

Amberlite IRA-904 Anion exchange resin (Rohm and Haas) [9050-98-0]. Washed with IM HCl, CH3OH (1 10) and then rinsed with distilled water until the washings were neutral to litmus paper. Finally extracted successively for 24h in a Soxhlet apparatus with MeOH, benzene and cyclohexane [Shue and Yan Anal Chem 53 2081 1981]. Strongly basic resin also used for base catalysis [Fieser Fieser Reagents for Org Synth 1511, Wiley 1967]. 

HCl aq EtOH). Recrystd from warm, acidified EtOH by addition of ammonia. The crude material (Ig) can be extracted with EtOH (50mL) in a Soxhlet apparatus for lOh to remove impurities. Impurities can be detected by paper electrophoresis. [Petrova et al. Anal Lett 5 695 1972.]... 

Silver(I) oxide [20667-12-3] M 231.7, m -200 (dec), d 7.13. Leached with hot water in a Soxhlet apparatus for several hours to remove any entrained electrolytes. 

A solution of CuCl, 2H20 (6.2 g, 22 mmol) in DMF (62 mL) was added to l,l9-dideoxy-2.8.12,18-tetra-ethyl-1,3.7,13,17,19-hexamethylbiladiene-ucdihydrobromide (1.2 g, 1.82 mmol) and the mixture was heated under reflux for 2 min. After cooling, the crystalline product was collected by filtration, washed with H20 and MeOH and extracted in a Soxhlet apparatus with CHC13. The extract was reduced to a volume of about 10 mL, and hot MeOH was added. Copper etioporphyrin II (13a) crystallized as red plates yield 598 mg (61 %). 

Hematoporphyrin dimethyl ester (15, 1.52 g, 2.43 mmol) (diastereomeric mixture) and Af.At-dimethyl-acetamide dimethyl acetal (8 mL) were suspended in o-xylcnc (100 mL), degassed and then heated with exclusion of light in a flask equipped with a reflux condenser and a Soxhlet apparatus containing 3 A molecular sieves. The temperature was raised during 15 min from rt to 115 C and kept at this temperature for 30 min. Then the temperature was raised to 155 C and the mixture kept at this temperature for 3 h. The mixture was evaporated in a bulb tube and the residue subjected to column chromatography [silica gel (ICN), CH2Cl2/MeOAc/MeOH 10 5 0.5] with exclusion of light yield of pure 16A 305 mg (17 %) yield of pure 16B, 375 mg (20%) and 187 mg (10%) of a mixture of 16 A and B. 

Di(phenylsulfanyl)phthalonitrilc (17, R = SPh 344 mg, 1 mmol) was heated in pentan-1-ol (50 mL) in the presence of DBU (152 mg, 1 mmol) under stirring and reflux for 48 h. After cooling, the dark-blue product was filtered, treated in a Soxhlet apparatus with MeOH and then with acetone, and dried in vacuo yield 213 mg (64%). 

Zinc(II) 1,8,15.22-tetraazaphthalocyanine (116 mg, 0.2 mmol) was suspended in anhyd DMF (60 mL) and dimethyl sulfate (7.65 mL, 0.08 mol) was added. The mixture was healed to 120 C with stirring under argon for 12 h. A ten-fold quantity of acetone was added resulting in the precipitation of a solid. The crude product was treated with anhyd acetone in a Soxhlet apparatus and dried in vacuo at 60 C over CaCl2 yield 61 mg (30%). 

Isolation of Citronellal and Citral. At the close of each experiment (7 to 10 days), the nests were frozen intact. Groups of 200 workers were placed in a micro-Soxhlet apparatus and extracted for 8 hours with methylene chloride. A few milligrams of carrier citronellal and citral were added and the mixture was applied to a thin-layer chromatoplate (silica gel G) which was developed with hexane-ethyl acetate (92 to 8) to separate citronellal and citral (3). The aldehydes were detected by spraying with a solution of 2, 4-dini-trophenylhydrazine in tetrahydrofuran (20) and the citronellal and citral peaks were scraped off and allowed to react with excess dinitro-phenylhydrazine reagent for a further 12 hours. 

Polysaccharide isolation. The silk floss (36 g) was cut and extracted with 2 1 benzene-EtOH in a Soxhlet apparatus for 16 h. The residue was extracted with 2 M... 

After 24 h of reaction, the catalytic bed was retrieved and sieved to separate the catalyst from the diluent. The used catalyst particles were placed in a Soxhlet apparatus, washed with n-hexane for 8 hours and then dried overnight at 393 K. Their carbon content was determined by automatic titration of the CO2 formed by burning the washed sample, in a Strohlein Coulomat 702 apparatus. 

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