Calcium double layer carbon

To obtain a maximum yield of the acid it is necessary to hydrolyse the by-product, iaoamyl iaovalerate this is most economically effected with methyl alcoholic sodium hydroxide. Place a mixture of 20 g. of sodium hydroxide pellets, 25 ml. of water and 225 ml. of methyl alcohol in a 500 ml. round-bottomed flask fitted with a reflux (double surface) condenser, warm until the sodium hydroxide dissolves, add the ester layer and reflux the mixture for a period of 15 minutes. Rearrange the flask for distillation (Fig. II, 13, 3) and distil off the methyl alcohol until the residue becomes pasty. Then add about 200 ml. of water and continue the distfllation until the temperature reaches 98-100°. Pour the residue in the flask, consisting of an aqueous solution of sodium iaovalerate, into a 600 ml. beaker and add sufficient water to dissolve any solid which separates. Add slowly, with stirring, a solution of 15 ml. of concentrated sulphuric acid in 50 ml. of water, and extract the hberated acid with 25 ml. of carbon tetrachloride. Combine this extract with extract (A), dry with a httle anhydrous magnesium or calcium sulphate, and distil off the carbon tetrachloride (Fig. II, 13, 4 150 ml. distiUing or Claisen flask), and then distil the residue. Collect the wovaleric acid 172-176°. The yield is 56 g. 

Mix 40 g (51ml, 0.67 mol) of propan-2-ol (isopropyl alcohol) with 460 g (310 ml) of constant boiling-point hydrobromic acid in a 500-ml flask fitted with a double surface condenser, add a few boiling chips and distil slowly (1-2 drops per second) until about half of the liquid has passed over. Separate the lower alkyl bromide layer (70 g), and redistil the aqueous layer when a further 7 g of the crude bromide will be obtained (1). Shake the crude bromide in a separatory funnel successively with an equal volume of concentrated hydrochloric acid (2), water, 5 per cent sodium hydrogen carbonate solution and water, and dry with anhydrous calcium chloride. Distil from a 100-ml flask the isopropyl bromide passes over at 59 °C. The yield is 66 g (81%). The p.m.r. spectrum (CC14, TMS) shows signals at 51.70 (d, 6H, Me2CH—) and 4.21 (sept, 1H, —CH—). 

First, 20 g of shell are cleaned thoroughly by sonication in double-distilled water. The outer layers of the shell are dissolved in 2M HCl, and then the remainder of the shell is dissolved completely in 6M HCl. Because of the amount of calcium carbonate present in the shell, the pH of the solution is raised during this step. It is thus necessary to evaporate the samples to 20 mL in a rotary evaporator. (Complete dryness is not possible, because of the hydroscopic property of the CaCl2 formed.) The sample is resuspended in 250 mL of 6M HCl and is hydrolyzed for 24 hr. The sample is brought nearly to dryness again in a rotary evaporator, is diluted with double-distilled water, and is desalted as described above. 

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