Funnels: filter separatory

Weigh 20 g of the plant sample into an Erlenmeyer flask and add 40 mL of 1 N HCl and 160 mL of acetonitrile. Shake the flask for 30 min at 300 strokes min using a shaker. Filter the aqueous acetonitrile extract through a No. 4 Kiriyama funnel filter paper. Wash the residue on the filter with 100 mL of acetonitrile. Combine the filtrates and remove acetonitrile with a rotary evaporator. Transfer the residue with 20 mL of saturated aqueous sodium chloride solution into a separatory funnel, extract the solution with 3 x 30 mL of n-hexane-ethyl acetate (9 1, v/v), and collect the organic phase in a flask. Dry with anhydrous sodium sulfate and remove the combined organic phase with a rotary evaporator. Transfer the residue into the Eppendorf tube with a... 

Concentrate the extracts to about 40 mL at 60 °C under reduced pressure in a rotary evaporator. Transfer the concentrate into a 250-niL separatory funnel, rinse the evaporation flask with 100 mL of aqueous 10% sodium chloride solution and then with 50 irL of dichloromethane, and add the rinsates to the separatory funnel. After shaking the separatory funnel, filter the lower organic phase over anhydrous sodium sulfate into a 250-mL evaporation flask. Repeat partitioning with a second portion of 50 irL of dichloromethane and combine the organic phases. Evaporate the solvent with a rotary evaporator at 40 °C. 

These metal rings come in various diameters to support filter funnels and separatory funnels. Often these support rings are coated in plastic to provide the cushion between metal and glass. 

The reaction mixture described above i.s cooled to 25° and carbonated by adding freshly crushed Dry Ice. The temperature falls rapidly when carbonation is complete. Ethanol (100 ml.) is added dropwisc (and cautiously) to destroy unreacted sodium after which 350 ml. of distilled water is added, also cautiously. The aqueous solution is separated in a separatory funnel, filtered and acidulated with 230 ml. of concentrated hydrochloric acid. The gray crystalline solid, 150 g., is filtered off, taken up in hot water, treated with decolorizing charcoal, filtered, and allowed to recrystallize as long white needles, m.p. 153-153.5°. Tins acid is not very soluble in hot water and is u.sually recrystallized batchwise from 2500 ml. of water in a 4-liter beaker. The mother liquor is recycled. 

In practice, it is best to purify a quantity, say one Winchester quart bottle, of technical 0 720 ether to cover the requirements of a group of students. The Winchester quart of ether is divided into two approximately equal volumes, and each is shaken vigorously in a large separatory funnel with 10-20 ml. of the above ferrous solution diluted with 100 ml. of water. The latter is removed, the ether transferred to the Winchester bottle, and 150-200 g. of anhydrous calcium chloride is added. The mixture is allowed to stand for at least 24 hours with occasional shaking. Both the water and the alcohol present are thus largely removed. The ether is then filtered through a large fluted filter paper into another clean dry Winchester bottle (CAUTION all flames in the vicinity must be... 

Sulphuric acid method. Place 20 g. of commercial cycZohexanol and 0-6 ml. of concentrated sulphuric acid in a 150 or 200 ml. round-bottomed or bolt head flask, add 2-3 chips of porous porcelain, and mix well. Fit the flask with a fractionating column, a Liebig condenser, adapter and filter flask receiver as in Section 111,10 (1). Heat the flask in an air bath (Fig. II, 5, 3) at such a rate that the temperature at the top of the column does not rise above 90° alternatively, an oil bath, heated to a temperature of 130-140°, may be used. Stop the distillation when only a small residue remains and the odour of sulphur dioxide is apparent. Transfer the distillate to a small separatory funnel. 

Equip a 1-litre three-necked flask with a powerful mechanical stirrer, a separatory funnel with stem extending to the bottom of the flask, and a thermometer. Cool the flask in a mixture of ice and salt. Place a solution of 95 g. of A.R. sodium nitrite in 375 ml. of water in the flask and stir. When the temperature has fallen to 0° (or slightly below) introduce slowly from the separatory funnel a mixture of 25 ml. of water, 62 5 g. (34 ml.) of concentrated sulphuric acid and 110 g. (135 ml.) of n-amyl alcohol, which has previously been cooled to 0°. The rate of addition must be controlled so that the temperature is maintained at 1° the addition takes 45-60 minutes. AUow the mixture to stand for 1 5 hours and then filter from the precipitated sodium sulphate (1). Separate the upper yellow n-amyl nitrite layer, wash it with a solution containing 1 g. of sodium bicarbonate and 12 5 g. of sodium chloride in 50 ml. of water, and dry it with 5-7 g. of anhydrous magnesium sulphate. The resulting crude n-amyl nitrite (107 g.) is satisfactory for many purposes (2). Upon distillation, it passes over largely at 104° with negligible decomposition. The b.p. under reduced pressure is 29°/40 mm. 

Into a 500 ml. three-necked flask, provided with a mechanical stirrer, a gas inlet tube and a reflux condenser, place 57 g. of anhydrous stannous chloride (Section 11,50,11) and 200 ml. of anhydrous ether. Pass in dry hydrogen chloride gas (Section 11,48,1) until the mixture is saturated and separates into two layers the lower viscous layer consists of stannous chloride dissolved in ethereal hydrogen chloride. Set the stirrer in motion and add 19 5 g. of n-amyl cyanide (Sections III,112 and III,113) through the separatory funnel. Separation of the crystalline aldimine hydrochloride commences after a few minutes continue the stirring for 15 minutes. Filter oflF the crystalline solid, suspend it in about 50 ml. of water and heat under reflux until it is completely hydrolysed. Allow to cool and extract with ether dry the ethereal extract with anhydrous magnesium or calcium sulphate and remove the ether slowly (Fig. II, 13, 4, but with the distilling flask replaced by a Claisen flask with fractionating side arm). Finally, distil the residue and collect the n-hexaldehyde at 127-129°. The yield is 19 g. 

Place 125 ml. of concentrated ammonia solution (sp. gr. 0-88) in a 600 ml. beaker and surround the latter with crushed ice. Stir the ammonia solution mechanically, and introduce the n-caproyl chloride slowly by means of a suitably supported separatory funnel with bent stem. The rate of addition must be adjusted so that no white fumes are lost. The amide separates immediately. Allow to stand in the ice water for 15 minutes after all the acid chloride has been introduced. Filter oflF the amide at the pump use the flltrate to assist the transfer of any amide remaining in the beaker to the Alter (2). Spread the amide on sheets of Alter or drying paper to dry in the air. The crude n-capro-amide (30 g.) has m.p. 98-99° and is sufficiently pure for conversion into the nitrile (Section 111,112) (3). Recrystallise a small quantity of the amide by dissolving it in the minimum volume of hot water and allowing the solution to cool dry on filter paper in the air. Pure n-caproamide has m.p. 100°. 

Separate the ketone layer from the water, and redistil the lattCT rmtil about one third of the material has passed over. Remove the ketone after salting out any dissolved ketone with potassium carbonate (5). Wash the combined ketone fractions four times with one third the volume of 35-40 per cent, calcium chloride solution in order to remove the alcohol. Dry over 15 g. of anhydrous calcium chloride it is best to shake in a separatory funnel with 1-2 g. of the anhydrous calcium chloride, remove the saturated solution of calcium chloride as formed, and then allow to stand over 10 g. of calcium chloride in a dry flask. Filter and distil. Collect the methyl n-butyl ketone at 126-128°. The yield is 71 g. 

Method 1. Arrange the flask containing the reaction mixture for steam distillation as in Fig. II, 40, 1. Proceed with the steam distillation until crystals of p-dibromobenzene appear in the condenser. Change the receiver and continue with the distillation until all the p-dibromobenzeiie has passed over from time to time run out the water from the condenser so that the crystals melt and run down into the receiver. Reject the residue in the flask. Transfer the first distillate to a separatory funnel, wash it with a httle water, and dry the lower layer with a little anhydrous magnesium sulphate or anhydrous calcium chloride filter. Distil slowly from a small distilling flask use a wire gauze or an air bath (Fig. II, 5, 3). Collect the fraction which passes over at 150-170° pour the residue (R), while it is still hot, into a small beaker or porcelain basin for the isolation of p-dibromobenzene. Redistil the fraction of b.p. 150-170° and collect the bromobenzene at 154-157° (3). The yield is 60 g. 

Method 2. Transfer the dark-coloured reaction product to a separatory funnel and shake successively with water, with sufficient 5-10 per cent, sodium hydroxide solution to ensure that the washings are alkaline to litmus, and finally with water. Dry with anhydrous magnesium sulphate or calcium chloride. Filter through a fluted filter paper into a small distilling flask and distil slowly. Collect the crude bromobenzene at 150-170° pour the residue whilst still hot into a small porcelain basin. Redistil the hquid of b.p. 150-170° (3) and collect the bromobenzene at 154-157° the yield is about 60 g. 

Transfer 30 g. of the hydrochloride to a 500 ml. separatory funnel, add 100 ml. of water and shake until a thin paste of uniform consistency is obtained add 10 per cent, aqueous sodium hydroxide solution in the cold with shaking until the whole mass has become bright green (the colour of the free base) and the mixture has an alkaUne reaction. Extract the free base by shaking with two 60 ml. portions of benzene (1). Dry the combined benzene extracts with a Uttle anhydrous potassium carbonate, and filter into a distiUing flask fitted with a water condenser. Distil off about half of the benzene, and pour the residual hot benzene solution into a beaker. Upon cooUng, the p-nitrosodimethylaniUne erystallises in deep green leaflets. Filter these off and dry them in the air. The yield of p-nitrosodimethylaniUne, m.p. 85°, from the hydrochloride is almost quantitative. 

---