Potassium carbonate removal

Dibromobutane (from 1 4-butanediol). Use 45 g. of redistilled 1 4-butanediol, 6-84 g. of purified red phosphorus and 80 g. (26 ml.) of bromine. Heat the glycol - phosphorus mixture to 100-150° and add the bromine slowly use the apparatus of Fig. Ill, 37, 1. Continue heating at 100-150° for 1 hour after all the bromine has been introduced. Allow to cool, dilute with water, add 100 ml. of ether, and remove the excess of red phosphorus by filtration. Separate the ethereal solution of the dibromide, wash it successively with 10 per cent, sodium thiosulphate solution and water, then dry over anhydrous potassium carbonate. Remove the ether on a water bath and distil the residue under diminished pressure. Collect the 1 4-dibromobutane at 83-84°/12 mm. the yield 3 73 g. 

Hydrolysis (or saponification) of n-butyl acetate. Boil 4-5 g. of n-butyl acetate (Section 111,95) with 50 ml. of 10 per cent, sodium hydroxide solution under reflux until the odour of the ester can no longer be detected (about 1 hour). Set the condenser for downward distiUation and coUect the first 10 ml. of distillate. Saturate it with potassium carbonate, aUow to stand for 5 minutes, and withdraw all the Uquid into a small pipette or dropper pipette. AUow the lower layer of carbonate solution to run slowly into a test-tube, and place the upper layer into a small test-tube or weighing bottle. Dry the alcohol with about one quarter of its buUr of anhydrous potassium carbonate. Remove the alcohol with a dropper pipette and divide it into two parts use one portion for the determination of the b.p. by the Siwoloboff method (Section 11,12) and convert the other portion into the 3 5-dinitrobenzoate (Section III, 27) and determine the m.p. 

Boil 2 g. of the ester with 30 ml. of 10 per cent, sodium or potassium hydroxide solution under reflux for at least 1 hour. If the alcohol formed is water (or alkali) soluble, the completion of the hydrolysis will be indicated by the disappearance of the ester layer. Distil ofiF the liquid through the same condenser and collect the first 3-5 ml. of distillate. If a distinct la3 er separates on standing (or upon saturation of half the distillate with potassium carbonate), remove this layer with a capillary dropper, dry it with a little anhydrous potassium carbonate or anhydrous calcium sulphate, and determine the b.p. by the SiwoloboflF method... 

Benzoyl piperidine. In a 1-litre three-necked flask, equipped with a mechanical stirrer, separatory funnel and a thermometer, place 85 g. (99 ml.) of redistilled piperidine (b.p. 105-108°) and a solution of 53 g. of sodium hydroxide in 400 ml. of water. Stir the mixture and introduce during the course of 1 hour 140 g. (115-5 ml.) of redistilled benzoyl chloride maintain the temperature at 35-40°, Cool to room temperature and extract the benzoyl piperidine with ether. Wash the ethereal solution with a little water to remove any dissolved sodium hydroxide, and dry with anhydrous potassium carbonate. Remove the ether on a water bath and distil the residue under diminished pressure (Fig. II, 20, 1). Collect the benzoyl piperidine at 184—186°/15 mm. it is an almost colourless viscous liquid and crystallises on standing in colourless needles m.p. 46°. The yield is 170 g. 

Reduction of A-nitrosomethylaniline. Into a 1 litre round-bottomed flask, fitted with a reflux condenser, place 39 g. of A-nitroso-methylaniline and 75 g. of granulated tin. Add 150 ml. of concentrated hydrochloric acid in portions of 25 ml. (compare Section IV.34) do not add the second portion until the vigorous action produced by the previous portion has subsided, etc. Heat the reaction mixture on a water bath for 45 minutes, and allow to cool. Add cautiously a solution of 135 g. of sodium hydroxide in 175 ml. of water, and steam distil (see Fig. II, 40, 1) collect about 500 ml. of distillate. Saturate the solution with salt, separate the organic layer, extract the aqueous layer with 50 ml. of ether and combine the extract with the organic layer. Dry with anhydrous potassium carbonate, remove the ether on a water bath (compare Fig. II, 13, 4), and distil the residual liquid using an air bath (Fig. II, 5, 3). Collect the pure methylaniline at 193-194° as a colourless liquid. The yield is 23 g. 

Decant the liquid layer into a 2 5 litre flask, and dissolve the sodium derivative of acetylacetone in 1600 ml. of ice water transfer the solution to the flask. Separate the impiue ethyl acetate layer as rapidly as possible extract the aqueous layer with two 200 ml. portions of ether and discard the ethereal extracts. Treat the aqueous layer with ice-cold dilute sulphimic acid (100 g. of concentrated sulphiu-ic acid and 270 g. of crushed ice) until it is just acid to htmus. Extract the diketone from the solution with four 200 ml. portions of ether. Leave the combined ether extracts standing over 40 g. of anhydrous sodium sulphate (or the equivalent quantity of anhydrous magnesium sulphate) for 24 hours in the ice chest. Decant the ether solution into a 1500 ml. round-bottomed flask, shake the desiccant with 100 ml. of sodium-dried ether and add the extract to the ether solution. Distil off the ether on a water bath. Transfer the residue from a Claisen flask with fractionating side arm (Figs. II, 24, 4r-5) collect the fraction boiling between 130° and 139°. Dry this over 5 g. of anhydrous potassium carbonate, remove the desiccant, and redistil from the same flask. Collect the pure acetji-acetone at 134r-136°. The yield is 85 g. 

The vinyl ether may be further purified by dissolving it in 15 ml of dry ether and adding a solution of 0.25 g of lithium aluminum hydride in 10 ml of dry ether. The mixture is refluxed for 30 minutes, and excess hydride is destroyed by addition of ethyl acetate (1 ml). Ice-cold dilute (0.5 N) sulfuric acid (25 ml) is gradually added to the cooled mixture, the ethereal layer is rapidly separated, the aqueous layer is extracted once with 10 ml of ether, and the combined ethereal solution is washed once with water and dried over potassium carbonate. Removal of the solvent, followed by distillation of the residue affords about 85% recovery of the pure vinyl ether, bp 102-10376 mm, 1.5045. 

Place 47 g (0.5 mol) of phenol, 60.5 g (0.5 mol) of allyl bromide (Expt 5.54), 69.1 g (0.5 mol) of anhydrous potassium carbonate and 100 ml of acetone in a 250-ml, two-necked round-bottomed flask fitted with a reflux condenser and sealed stirrer unit, and boil on a steam bath for 8 hours with stirring. Pour the reaction mixture into 500 ml of water, separate the organic layer and extract the aqueous layer with three 20 ml portions of ether. Wash the combined organic layer and ether extracts with 2 m sodium hydroxide solution, and dry over anhydrous potassium carbonate. Remove the ether with a rotary evaporator and distil the residue under reduced pressure. Collect the allyl phenyl ether, b.p. 85°C/19mmHg the yield is 57 g (85%). 

Dissolve 29 g of potassium hydroxide in 27 ml of water contained in a beaker or conical flask, and cool the solution to about 20 °C in ice-water. Pour the solution into a 250-ml reagent bottle, and add 32 g (30 ml, 0.3 mol) of pure benzaldehyde (1) cork the bottle securely and shake the mixture vigorously until it has been converted into a thick emulsion. Allow the mixture to stand overnight or for 24 hours in the stoppered bottle. Add just sufficient water (about 105 ml) to dissolve the potassium benzoate. Pour the liquid into a separatory funnel, rinse out the bottle with about 30 ml of ether and add this ether to the solution in the funnel. Shake the solution in order to thoroughly extract the benzyl alcohol with the ether, separate the lower aqueous solution and carry out two further extractions each with about 25 ml of ether. Save the aqueous solution. Combine the ether extracts and distil the ether from a water bath (rotary evaporator) until the volume is about 25 ml. Cool and shake the ether solution twice with 5 ml portions of saturated sodium metabisulphite solution in order to remove any benzaldehyde which may be present. Separate the ethereal solution, wash it with 10 ml of 10 per cent sodium carbonate solution (to ensure complete removal of the bisulphite), then with 10 ml of water, and dry with anhydrous magnesium sulphate or anhydrous potassium carbonate. Remove the ether (Fig. 2.98 50-ml distilling flask) on a water bath, and distil the residual liquid from an air bath replace the water condenser by an air condenser or empty the water completely from the condenser jacket. Collect the benzyl alcohol at 204-207 °C (the pure compound boils at 205.5 °C). The yield is 13 g (86.5%). 

In the molten carbonate process a molten eutectic mixture of lithium, sodium, and potassium carbonates removes sulfur oxides from power plant stack gases. The resulting molten solution of alkali metal sulfites, sulfates, and unreacted car bonate is regenerated in a two-step process to the alkali carbonate for recycling. Hydrogen sulfide, which is evolved in the regeneration step, is converted to sulfur in a conventional Claus plant. A 10 MW pilot plant of the process has been constructed at the Consolidated Edison Arthur KiU Station on Staten Island, and startup is underway. 

---