Carbon boil reaction

Reaction with sodium carbonate. Boil about 0 5 g. of 0- and of />-nitrophenol in turn with Na2C03 solution, using the method described in Section 5, p. 336, and note the evolution of CO2. 

The manufacture of a related compound is first described. 28.1 parts of p-chloro-benzhy-dryl bromide are heated to boiling, under reflux and with stirring, with 50 parts of ethylene chlorohydrin and 5.3 parts of calcined sodium carbonate. The reaction product is extracted with ether and the ethereal solution washed with water and dilute hydrochloric acid. The residue from the solution in ether boils at 134° to 137°C under 0.2 mm pressure and is p-chloro-benzhydryl-(/3-chloroethyl) ether. 

Precipitate with aq. ammonia. Evaporate the soln. down to about 100 c.c., and filter the ot liquid so as to remove calcium sulphate. The cone. soln. is sat. with ammonium alum and allowed to stand for some time. The mixed crystals of potassium, rubidium, and oeesium alums and of lithium salt are dissolved in 100 c.c. of distilled water and recrystal-lized. The recrystallization is repeated until the crystals show no spectroscopic reaction for potassium or lithium. The yield naturally depends on the variety of lepidolite employed. 100. grms of an average sample gives about 10 grms. of crude crystals and about 3 grms. of the purified caesium and rubidium alums. For the purification of caesium and rubidium salts, see the chlorides. The mother-liquors are treated with an excess of barium carbonate, boiled, and filtered. The filtrate is acidified with hydrochloric acid, and evaporated to dryness. The residue is extracted with absolute alcohol in which lithium chloride is soluble, and the other alkali chlorides are sparingly soluble. 

Place 1.55 g (0.0675 mol) of clean sodium in a 250-ml round-bottomed flask equipped with a reflux condenser. Add 40 ml of absolute alcohol (or rectified spirit). If all the sodium has not disappeared after the vigorous reaction has subsided, warm the flask on a water bath until solution is complete. Cool the mixture and add 10 g (0.066 mol) of p-hydroxyacetanilide. Introduce 15 g (8 ml, 0.1 mol) of ethyl iodide slowly through the condenser and reflux the mixture for 45-60 minutes. Pour 100 ml of water through the condenser at such a rate that the crystalline product does not separate if crystals do separate, reflux the mixture until they dissolve. Then cool the flask in an ice bath collect the crude phenacetin with suction and wash with a little cold water. Dissolve the crude product in 80 ml of rectified spirit if the solution is coloured, add 2 g of decolourising carbon, boil and filter. Treat the clear solution with 125 ml of hot water and allow to cool. Collect the pure phenacetin at the pump and dry in the air. The yield is 9.5 g (80%), m.p. 137 °C. 

Notice that each value of AG° refers to one mole of 02 or Cl2 as appropriate. Notice also that were it not for the reducing effect of the carbon, the reaction would not be possible. (There are several metal oxides, for example those of copper, iron and zinc, which may be chlorinated by chlorine alone.) The TiCl4 is a volatile, essentially covalent liquid with a boiling point of 136°C, which must be of high purity if a high quality titanium product is to be obtained. 

Acid carbonates are compounds of both a metal and hydrogen in combination with the carbonate radical. They are formed by the action of an excess of carbonic acid on a normal carbonate. This reaction, however, can be reversed by boiling off the carbonic acid as carbon dioxide and water. 

Excellent yields of annelated 4-thioxopyrimidin-2-ones have been obtained by condensing oaminonitriles with carbonyl sulfide (24 hr in boiling etha-nolic sodium ethoxide). Thus, 2-amino-3-cyanothiophene (see 11) gave 4-thioxothieno[2,3-d]pyrimidin-2-one (135), and 3-amino-4-cyanopyrazole (see 15) formed 4-thioxopyrazolo[3,4-rf]pyrimidin-6-one (see 16). The reaction is thought to follow the course of the above carbon disulfide reaction.190... 

LDNR is generally prepared from 2,4-dinitroresorcinol and soluble lead salt (nitrate or acetate) via the sodium salt (introduced as sodium carbonate). The reaction is carried out in hot or boiling water [8-10, 14, 15]. 

This produces sufficient concentrations of magnesium and calcium ions to render the water hard. The above reaction is readily reversed by boiling the water when the magnesium and calcium ions responsible for the hardness are removed as the insoluble carbonate. 

If the hydrogencarbonate is in solution and the cation is Ca or Mg. the insoluble carbonate is precipitated this reaction may be used, therefore, to remove hardness in water by precipitation of Ca or Mg ions.) The ease of decomposition of hydrogencar-bonates affords a test to distinguish between a hydrogencarbonate and a carbonate carbon dioxide is evolved by a hydrogencarbonate, but not by a carbonate, if it is heated, either as the solid or in solution, on a boiling water bath. 

Reactions of Picric Acid, (i) The presence of the three nitro groups in picric acid considerably increases the acidic properties of the phenolic group and therefore picric acid, unlike most phenols, will evolve carbon dioxide from sodium carbonate solution. Show this by boiling picric acid with sodium carbonate solution, using the method described in Section 5, p. 330. The reaction is not readily shown by a cold saturated aqueous solution of picric acid, because the latter is so dilute that the sodium carbonate is largely converted into sodium bicarbonate without loss of carbon dioxide. 

SULPHANILAMIDE. (Reaction C.) Add 15 g. of the above thoroughly drained sulphonamide to 10 ml. of concentrated hydrochloric acid diluted with 20 ml. water, and boil the mixture gently under reflux for i hour. Then add 30 ml. of water and heat the mixture again to boiling, with the addition of a small quantity of animal charcoal. Filter the boiling solution, and add powdered sodium carbonate in small quantities to the filtrate with stirring until all eflFervescence ceases and the sulphanilamide is precipitated as a white powder. Cool the mixture thoroughly and filter oflF the sulphanilamide at the pump, wash with water and dry. Yield, ca. 10 g. 

Di-n-amyl ether. Use 50 g. (61 5 ml.) of n-amyl alcohol (b.p. 136-137°) and 7 g. (4 ml.) of concentrated sulphuric acid. The calculated volume of water (5 ml.) is collected when the temperature inside the flask rises to 157° (after 90 minutes). Steam distil the reaction mixture, separate the upper layer of the distillate and dry it with anhydrous potassium carbonate. Distil from a 50 ml. Claisen flask and collect the fractions of boiling point (i) 145-175° (13 g.), (ii) 175-185° (8 g.) and (iii) 185-190° (largely 185-185-5°) (13 g.). Combine fractions (i) and (u), reflux for 1 hour in a small flask with 3 g. of sodium, and distil from the sodium amyloxide and excess of sodium this yields 9 5 g. of fairly pure n-amyl ether (iv). The total yield is therefore 22 - 5 g. A perfectly pure product, b.p. 184 185°, is obtained by further distillation from a Little sodium. 

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