Baryta Water

When trigonelline is heated in closed tubes with baryta water at 120°, it gives rise to methylamine, whilst similar treatment with hydrochloric acid at 260° furnishes methyl chloride and nicotinic acid (pyridine-3-carboxylic acid), indicating that it is the methylbetaine of nicotinic acid. 

When heated with mineral acids Z-cocaine is hydrolysed into Z-ecgonine (p. 96), benzoic acid and methyl alcohol and a like change takes place with baryta water. If the alkaloid is boiled with water, methyl alcohol is split off and a new base, benzoyl-Z-ecgonine is formed, which in turn can be hydrolysed by acids or alkalis into Z-ecgoninc and benzoic acid. Cocaine is, therefore, methylbenzoyl-Z-ecgonine. 

Tropacocaine (Benzoyl-ili-tropeine), CuHj gOgN, was discovered by Giesel in Java coca leaves and has since been found in Peruvian coca. Its preparation from the former source has been described by Hara and Sakamoto, It crystallises in needles, m.p. 49°, is insoluble in water, but soluble in alcohol, ether or dilute ammonia and is generally prepared by benzoylating /t-tropine, and purified as the hydrochloride. Its alcoholic solution is alkaline and optically inactive. The hydrochloride forms needles, m.p. 271° (dec.), and the hydrobromide leaflets. The aurichloride separates in minute yellow needles, m.p. 208°, from hot aqueous solutions the picrate has m.p. 238-9°. When heated with hydrochloric acid or baryta water the alkaloid is hydrolysed to benzoic acid and -tropine. ... 

Phenyl-ethyl isothiocyanate. CgHj,(C.2H4)N C S, has been found in the oils of reseda root, nasturtium, and some varieties of Brassica. It is an oil of powerful odour, yielding a thiourea, melting at 137°. The latter body, when treated with silver nitrate and baryta water, yields phenyl-ethyl-urea, melting at 111° to 112°. 

Methyl Ethyl Ketone. 1 mole (20 g) of methylacetoacetic ester are refluxed with 250 cc of baryta water (saturated) until the oily layer disappears. Distill on a water bath to 90°. Stir violently or shake for three hours with a saturated solution of sodium bisulfate, and collect the crystals and distill with an excess of dilute sulfuric acid at 90°. The distillate is dried over calcium chloride and distilled again, retaining the fraction at 79-82°. Yield 70% theoretical (7 g). 

The next operation consists in the reconversion of the esters into the amino acids. In the case of the lower boiling fractions, this reconversion is effected by boiling the esters with five to six voluiiies of water under a reflux condenser for six to seven hours, until the alkaline reaction has disappeared in the case of the higher boiling fractions, which contain the esters of aspartic and glutamic acids, the reconversion is effected by boiling with baryta water for one and a half to two hours hydrolysis by water alone only converts these esters into their acid esters. Phenylalanine ester is converted into its hydrochloride by evaporation to dryness with hydrochloric acid. 

Serine.—Its ester is contained in the fractions which distil between ioo° and 130° at O 5 mm. The mixed esters contained in this fraction are treated with a small quantity of water and then with five to six volumes of petroleum ether, which precipitates serine ester as an oil the oil is then shaken up with petroleum ether to remove admixtures as far as possible and is hydrolysed with baryta water. On removal of the baryta it crystallises when the solution is concentrated, and it is purified by treatment with alcohol, which dissolves other substances which are also present, and recrystallisation from water. Its )8-naph-thalene sulpho-derivative. 

The liquid is now neutralised with baryta, and barium nitrate is added, so long as a precipitate of barium sulphate is formed this is filtered off and washed. The filtrate is concentrated to 300 c.c. and treated with silver nitrate, as before, till a test drop gives a yellow colour with baryta when this occurs it is exactly neutralised with baryta, and from a burette small quantities of baryta are added till the silver salt of histidine is completely precipitated this is determined by taking out a drop when the precipitate has settled and testing with ammoniacal silver solution if a precipitate easily soluble in excess of ammonia be formed, when the two liquids come together, histidine is still present and more baryta water must be added, until it is completely thrown out, when it is filtered off, stirred up with water, again filtered off and washed out. 

The product mixture is filtered to remove insoluble CaS04. The aqueous solution of hypophosphorous acid is concentrated under reduced pressure. Concentrated baryta water may be used instead of calcium hydroxide. 

Co(NH3)8](OH)3, the parent substance from which the hexammino-salts are derived, is obtained in aqueous solution by treating the corresponding sulphate, [Co(NH3)8]2(S04)3.5H20, with baryta water,... 

The hydroxo-compoimd of the series, dihydroxo-diainmino-platinum, [Pt(NH3)2(QH)2], is formed by treating the sulphato-derivative with baryta water. A solution is obtained which is strongly alkaline, liberates ammonia from ammonium salts, absorbs carbon dioxide, and precipitates metallic salts. From the solution the hydroxide may be easily crystallised.1... 

Heated with baryta water in an atmosphere of nitrogen, carbon disulphide yields barium hydrosulphide, which is subsequently converted into sulphate by contact with the air (see p. 264) 5... 

Carbon disulphide may be estimated gravimetrically by treatment with baryta water (see p. 262), whereby barium sulphide is produced, which is then oxidised and weighed as sulphate.2... 

A clear, colorless liquid, of strongly alkaline reaction. Baryta water contains 3.3 per cent of crystallized barium hydroxide, Ba(OII)2 4- 8H20. 

The tests to be made arc those given under Barium Hydroxide. But for each gram of crystallized barium hydroxide, 30 cc. of baryta water arc to be taken. The quantitative determination is made as follows. 

Quantitative Determination. — Titrate 50 cc. of baryta water with normal hydrochloric acid, using methyl orange as the indicator. At least 10.5 cc. of normal hydrochloric acid should be required to produce the red end-point. 

Dissolve l gm. of litmus in 3(X) ee. of hot water, and add, drop by (Imp, dilute sulphuric add until the liquid acquires a red color. Then boil for ten minutes in order to expel completely the carbon dioxide. Should (lie red color pass into blue (luring the boiling, the color is restored by again adding dilute, sulphuric acid. Now add baryta water, drop by drop, until a violet color develops, sot aside to deposit,... 

Barium Vanadite forms two hydrates, BaV409.4H20 and BaV409. 5Ii20, which are obtained by the action of excess of baryta water on a solution of vanadyl dichloride.2 They are brown, amorphous substances, easdy soluble in nitric and hydrochloric acids. 

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