Chloroform extract

Continuous ether extraction and continuous chloroform extraction. When a substance X is shaken up with ether and water it will distribute itself according to the relative solubilities in each solvent. 

A convenient alternative apparatus for continuous chloroform extraction is shown in Fig. 18 (b). 

Neutralise the cold contents of the flask with 500-600 ml. of 40 per cent, aqueous sodium hydroxide solution, equip the flask for steam distillation and steam distil until about 1 litre of distillate is collected. The steam distillate separates into two layers. Add solid sodium hydroxide (< 100 g.) to complete the separation of the two layers as far as possible. Remove the upper (organic) layer and extract the aqueous layer with three 50 ml. portions of chloroform. Dry the combined organic layer and chloroform extracts with anhydrous potassium carbonate and distil the mixture through a short fractionating column (e.g., an 8 Dufton column) after a fore run of chloroform, followed by pyridine, collect the crude 4-ethylpyridine at 150-166° (49 g.). Redistil through a Fenske-... 

A iridine traces in aqueous solution can be determined by reaction with 4-(p-nitroben25l)pyridine [1083-48-3] and potassium carbonate [584-08-7]. Quantitative determination is carried out by photometric measurement of the absorption of the blue dye formed (367,368). Alkylating reagents interfere in the determination. A iridine traces in the air can be detected discontinuously by absorption in Folin s reagent (l,2-naphthoquinone-4-sulfonate) [2066-93-5] (369,370) with subsequent chloroform extraction and hplc analysis of the red dye formed (371,372). The detection limit is ca 0.1 ppm. Nitrogen-specific thermal ionisation detectors can be used for continuous monitoring of the ambient air. 

Oil Expressed as oil or chloroform extractable matter, ppmw Scale, sludge and foaming in boilers impedes heat exchange undesirable In most processes Baffle separators, strainers, coagulation and filtration, diatomaceous earth filtration... 

The melt is cooled to 0°, 50 ml. of 10% aqueous sodium hydroxide solution is added, and the mixture is extracted with four 50-ml. portions of chloroform. The combined chloroform extracts are washed with two 25-ml. portions of water, and these in turn are extracted with 10 ml. of chloroform. The organic layers are combined and dried partially over anhydrous sodium sulfate. The solvent is removed by distillation on the steam bath, and the residue is distilled at reduced pressure from a 50-ml. distilling flask. After a fore-run of about 4 g. (Note 3), b.p. 60-70°/ 1.5 mm. (bath temperature taken up to 125°), the cyanoethyl-aniline is collected at 115-120°/0.01 mm. The product solidifies in the form of colorless plates, m.p. 48-51° (Note 4). The yield is 10.5-11.4 g. (72-78%) (Note 5). 

The collected solid is extracted twice with 400-500 ml. portions of boiling chloroform, the combined extracts are used to extract the aqueous filtrates contained in the separatory funnel, and the extraction is repeated with several fresh 500-ml. portions of chloroform. The combined chloroform extracts are then given preliminary drying over anhydrous sodium sulfate and evaporated to dryness by distillation under reduced pressure. The residue is transferred to a 2-1. Erlenmeyer flask and dissolved in... 

A detailed procedure for the use of MCPBA recently appeared in Reagents for Organic Synthesis by Fieser and Fieser. The commercially available MCPBA (Aldrich) is 85% pure the contaminant, m-chlorobenzoic acid, can be removed by washing with a phosphate buffer of pH 7.5. The epoxidation is usually performed as follows a solution of 3 -acetoxy-5a-androst-16-ene (2.06 g, 6.53 mmoles) in 25 ml of chloroform (or methylene dichloride) is chilled to 0° in a flask fitted with a condenser and drierite tube and treated with a solution of commercial MCPBA (1.74 g, 20% excess) in 25 ml chloroform precooled to the same temperature. The mixture is stirred and allowed to warm to room temperature. After 23 hr (or until TLC shows reaction is complete) the solution is diluted with 100 ml chloroform and washed in sequence with 100 ml of 10% sodium sulfite or sodium iodide followed by sodium thiosulfate, 200 ml of 1 M sodium bicarbonate and 200 ml water. The chloroform extract is dried (MgS04) and evaporated in vacuo to a volume of ca. 10 ml. Addition of methanol (10 ml) followed by cooling of the mixture to —10° yields 0.8 gof 16a,17a-epoxide mp 109.5-110°. Additional product can be obtained by concentration of the mother liquor (total yield 80-90%). 

A solution of hydrazoic acid (prepared from about 30 g sodium azide) in ca. 200 ml chloroform is prepared in a well-ventilated hood. Cholesterol (15 g) is dissolved in the hydrazoic acid solution and 3.5 ml of triethylamine is added. The reaction mixture is then stirred at room temperature while 7 g of A-chlorosuccinimide is added. The reaction mixture is allowed to stand overnight and then the chloroform solution is washed successively with dilute sodium bisulfite, dilute soldium bicarbonate solutions and finally with water. The chloroform extract is then dried (Na2S04) and the solvent removed in vacuo. The residue is crystallized from ethanol to yield ca. 8.5 g of (101) in colorless needles mp 138-139°. The chloro azide is reduced to the aziridine by lithium aluminum hydride according to the foregoing procedure. 

Bromo-4-methoxy-A-homo-estra-2,4,5(10)-trien-17-one (44 0. 2g), is dissolved in formic acid, 2 ml of boron trifluoride etherate is added and the mixture is stirred vigorously at 0° for 2 hr. A brown mass ca. 0.12 g) is obtained after evaporation of the solvents at reduced pressure. This material is diluted with water and extracted with chloroform. The chloroform extracts are washed successively with water and saturated salt solution, dried over anhydrous magnesium sulfate and evaporated at reduced pressure to give 95 mg of a product which is purified by filtration through a column of neutral alumina and crystallization of the residue after evaporation of the solvent from ethyl acetate-petroleum ether. The resulting A-homo-estra-l(10),2,4a-triene-4,17-dione (45), mp 143-146°, is identical to the tropone (45) prepared from monoadduct 17-ketone (43a). 

Bromo-A-homo-estra-4y5 0)-diene-3, l-dione (49). A solution of silver perchlorate (0.55 g, 5 mole-eq) in acetone (2 ml) is added to a refluxing solution of monoadduct (48 0.28 g) in acetone (30 ml) containing water (0.5 ml). After being heated at reflux for 25 min the reaction mixture is cooled and the precipitated silver bromide is removed by filtration, yield about 0.11 g. The filtrate is diluted with water (500 ml) and is thoroughly extracted with chloroform. The chloroform extracts are washed with water and saturated salt solution, dried over anhydrous magnesium sulfate, and evaporated at... 

A-Homo-estra-, 4, )-triene-3, l-dione (50). A solution of bromo ketone (49 0.2 g), silver perchlorate (0.5 g) and 20% aqueous acetone (30 ml) is heated at reflux with stirring for 30 min and then allowed to cool to room temperature. The mixture is filtered to remove precipitated silver bromide (ca. 0.19 g) and the filtrate is diluted with water (200 ml) and then extracted with chloroform. The chloroform extracts are washed, successively with water, 5% sodium bicarbonate solution, water and saturated salt solution. After being dried over anhydrous magnesium sulfate, the solvents are removed at reduced pressure to give a solid. Recrystallization from ethyl acetate gives A-homo-estra-l,4,5(10)-triene-3,17-dione (50 0.17 g) mp 193-197°. 

Cyclohexanedione (5) 2,5-Dicarbethoxy-l,4-cyclohexanedione (10 g) is suspended in a solution of 34 g of 85 % phosphoric acid, 250 ml of water, and 5 ml of ethanol in a 500-ml round-bottom flask. The mixture is refluxed for 5 days (or until all the solid material has dissolved), cooled, and extracted six times with 100-ml portions of chloroform (or better, continuously extracted with chloroform). The combined chloroform extracts are dried (sodium sulfate) and the solvent is removed (rotary evaporator). The residue on distillation affords 1,4-cyclohexanedione, bp 130-133720 mm. The product solidifies and may be recrystallized from carbon tetrachloride, mp 11-19°. 

In a 500-ml round-bottom flask fitted with a condenser, and a heating mantle is placed a mixture of 25 g of diethyl 5-(l -carboxy-2 -oxocyclohexyl)valerate, 70 g of barium hydroxide, and 200 ml of methanol, and the mixture is refluxed for 24 hours. After cooling, the mixture is acidified (pH 4) by cautious addition of cold 10% aqueous hydrochloric acid. The acidified solution is saturated with sodium chloride and then extracted three times with 100-ml portions of chloroform. The combined chloroform extracts are dried (anhydrous magnesium sulfate) and evaporated. On vacuum distillation, the residue affords the product (about 15 g), bp 176-17870.5 mm. 

Crude 5 -butyramldo-2 -(2,3-apoxypropoxy)acetophenone (16 g), isopropylamine (20 g) and ethanol (100 ml) were heated together under reflux for 4 hours. The reaction mixture was concentrated under reduced pressure and the residual oi) was dissolved in N hydrochloric acid. The acid solution was extracted with ethyl acetate, the ethyl acetate layers being discarded. The acidic solution was brought to pH 11 with 2 N aqueous sodium hydroxide solution end then extracted with chloroform. The dried chloroform extracts were concentrated under re-... 

The acetic acid solution was poured into water (100 ml) and extracted with chloroform. The chloroform extracts were washed in turn with water, saturated sodium bicarbonate solution and water, dried and evaporated in vacuo. The residual gum was triturated with ether and a white crystalline solid (1.16 grams) isolated by filtration. Recrystallization from ether (containing a small amount of acetone)-petroleum ether gave 9a-fluoro-110,21-dihydroxy-160-methyl-1 7a-valeryloxypregna-1,4-diene-3,20-dione (871 mg) as fine needles. 

The mixture is heated at reflux for two hours with continual agitation and there is then added dropwise a solution of 2-methyl-3-dimethylaminopropyl chloride in an equal volume of Xylene. The mixture is then heated for fifteen hours, after which time it is cooled and decomposed by the cautious addition of ice water. The layers are separated and the aqueous layer extracted with ether. The combined organic layers are next extracted with 10% hydrochloric acid and the acidic extracts then rendered alkaline by the addition of ammonium hydroxide. The precipitated oil is extracted three times with chloroform. The chloroform extracts are dried and concentrated in vacuo, the residue being distiiled to yield the product. 

The resulting slurry was extracted with four 300 ml portions of chloroform. The aqueous phase was discarded. The combined chloroform extract was washed once with 100 ml of saturated aqueous sodium chloride solution and the sodium chloride phase was discarded. The chloroform phase was evaporated to dryness under vacuum on a 50° to 60°C water bath and an equal volume of methanol was added to the residue and the resulting solution heated at reflux for 1 hour. The methanol solution was evaporated to dryness under vacuum on a 50° to 60°C water bath. The residue was a clear pale yellow viscous oil. An equal volume of water and 10 ml of 37% aqueous HCI was added and the resultant was shaken until the oil dissolved and a white solid (more 0jPO) remained in suspension. The suspension was filtered through a sintered glass mat at pH 1 to 2 and the solid discarded. 

The ethyl p-chlorophenoxyisobutyrate may be obtained by heating a mixture of 206 parts of dry p-chlorophenoxyisobutyric acid, 1,000 parts of ethanol and 40 parts of concentrated sulfuric acid under reflux during 5 hours. The aicohol is then distilled off and the residue is diluted with water and extracted with chioroform. The chloroform extract is washed with sodium hydrogen carbonate solution, dried over sodium sulfate and the chloroform removed by distillation. The residue is distilled under reduced pressure and there is obtained ethyl p-chlorophenoxyisobutyrate, BP 148° to 150°C/20 mm. 

When addition is complete the mixture is heated under reflux during 5 hours and then the acetone is removed by distillation. The residue is dissolved in water, acidified with hydrochloric acid and the mixture extracted with chloroform. The chloroform extract is stirred with sodium hydrogen carbonate solution and the aqueous layer is separated. The alkaline extract is acidified with hydrochloric acid and filtered. The solid product is drained free from oil on a filter pump, then washed with petroleum ether (BP 40° to 60°C), and dried at 50°C. The solid residue, MP 114° to 116°C, may be crystallized from methanol (with the addition of charcoal) to give p-chlorophenoxyisobutyric acid, MP 118° to 119°C. 

A solution of 1.0 g of A -3,11-diketo-20-cyano-21-acetoxy-pregnene in 10 cc of benzene is treated with 1.0 g of osmium tetroxide and 0.43 g of pyridine. After standing at room temperature for 18 hours, the resulting solution is treated successively with 50 cc of alcohol, and with 50 cc of water containing 2.5 g of sodium sulfite. The mixture is stirred for 30 hours, filtered, and the filtrate acidified with 0.5 cc of acetic acid and concentrated to small volume in vacuo. The aqueous suspension is then extracted four times with chloroform, the chloroform extracts are combined, washed with water and concentrated to dryness in vacuo. Recrystallization of the residue from acetone gives 3,11,20-triketo-17(a)-21-dihydroxy-pregnane MP 227° to 229°C. This compound is then treated with acetic anhydride and pyridine for 15 minutes at room temperature to produce 3,11,20-triketo-17(a)-hydroxy-21-acetoxy-pregnane or cortisone acetate. 

In an initial step, dibenzo[a,d] cyclohepten-5-one is reacted with the Grignard reagent of 3-di-methylaminopropyl chloride and hydrolyzed to give 5-(3-dimethylaminopropyl)-dibenzo[a,d] -[1,4] cycloheptatriene-5-ol. Then 13 g of that material, 40 ml of hydrochloric acid, and 135 ml of glacial acetic acid is refluxed for 314 hours. The solution is then evaporated to dryness in vacuo and added to ice water which is then rendered basic by addition of ammonium hydroxide solution. Extraction of the basic solution with chloroform and removal of the solvent from the dried chloroform extracts yields the crude product which when distilled in vacuo yields essentially pure 5-(3-dimethylaminopropylidene)-dibenzo[a/f ] [ 1,4] cycloheptatriene, BP 173°C to 177°C at 1.0 mm. 

Dione 21-Acetate To a stirred solution of 500 mg of 9o-fluoro-11(3,21-dihydroxy-16-methyl-1,4,16-pregnatriene-3,20-dione 21-acetate in 5 ml of benzene and 5 ml of chloroform are added 0.50 ml of t-butyl hydroperoxide and 0.1 ml of a 35% methanolic solution of benzyl-trimethyl ammonium hydroxide. After 18 hours at room temperature, water is added and the mixture thoroughly extracted with chloroform. The chloroform extract is washed with saturated aqueous sodium chloride and dried over magnesium sulfate. Evaporation of the Solvent and crystallization of the residue from acetone-ether gives Bo-fluoro-... 

The methanol is evaporated with agitation. The residue is dissolved in 1.5 liters water and is repeatedly extracted with chloroform. The combined chloroform extracts are evaporated to dryness, and the residue is recrystalllzed from carbon tetrachloride. 80 g of 2-amlno-5-methoxyethoxypyrimidine of MP 80°C to 81 °C are obtained. 

IB) 21-Chloro-90i-fluoro- -pregnene-11 160l,170i-triol-3,2Q-d ane 16,17-acetonlde A solution of 200 mg of the acetonide 21-mesylate from part (A) and 900 mg of lithium chloride in 25 ml of dimethylformamide is kept at 100°C for 24 hours. The mixture is poured on ice, extracted with chloroform and the chloroform extract washed with water and dried over sodium sulfate. Evaporation of the solvent in vacuo furnishes the crystalline chloride, which after recrystallization from acetone-ethanol has a melting point about 276°C to 277°C. 

After chilling to -t-12°C, additional methanol (35 ml) and a concentrated aqueous ammoniurt hydroxide solution (1.4M) (100 ml) are added and stirring is continued for 2 hours at a temperature maintained at from -t-5° to -H5°C. The organic layer is separated and solvent is stripped from the aqueous layer at water aspirator pressure at a temperature below 40°C. The residue is extracted several times with chloroform and the chloroform extracts are combined with the separated oil. Chloroform is removed at water aspirator pressure at a temperature below 35°C to leave crude q-amino- -methylmercaptobutyronitrile (methionine nitrile) in 88% yield (68 g) as a clear, somewhat viscous oil. 

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