Metal residue after hydrochloric acid reaction

A mixture of 1.0 g of 6,6,9-trimethyl-9-azabicyclo[3.3.1 ] nonan-3/3-ol, methyl 0i,0i-di-(2-thienyD-glycollate and 30 mg of metallic sodium is heated at 80°C to 90°C for about 2 hours under reduced pressure. After cooling, ether is added to the reaction mixture. The mixture is extracted with 10% hydrochloric acid. The aqueous layer is alkalified with sodium carbonate and reextracted with ethyl acetate. The extract is washed with water, dried and concentrated to dryness. The residue thus obtained is treated with hydrogen chloride by conventional manner. 2.0 g of the 0i,0i-di-(2-thienyl)glycollate of 6,6,9-trimethyl-9-azabicyclo-(3.3.1 ] nonan-3/3-ol hydrochloride are obtained. Yield 83%. 

This 0 -benrylmercaptopropionylglycine (60 g) is dissolved in 400 ml of liquid ammonia, kept at about -50 C, and 12g of sodium metal is gradually added thereto. After the reaction, excess ammonia is removed therefrom, the residue is dissolved in water, washed with ether and the residual aqueous layer is adjusted to pH 1 with hydrochloric acid and concentrated in vacuo in a stream of hydrogen sulfide. The crystalline residue is dried and recrystallired from ethyl acetate to give 25 g of 0 -mercaptopropionylglycine of melting point 95°C to 97°C. 

The obtained in (1) above were dissolved in 500 ml of liquid ammonia and 21.1 g of metallic sodium were added slowly with stirring. After completion of reaction, 59.4 g of ammonium chloride were added and thereafter the ammonia was removed by distillation. Water was added to the residue to dissolve the solid. The resulting water layer was separated, washed with ethyl acetate, and acidified with hydrochloric acid under cooling. The precipitates thus obtained were extracted with ethyl acetate. The extract was washed with water, dried over sodium sulfate and evaporated to dryness. The product weighed 43.6 g, representing a yield of 88%. After recrystallization from ethyl acetate, the desired compound, melting at 139°-140°C, was obtained. [[Pg.692]

The suitability of filter paper for ordinary pharmaceutical purposes may be determined by the application of a few simple tests. Distilled water which has been passed through the paper should leave no residue on evaporation, showing that the paper contains no soluble mineral sub stances. Similarly diluted hydrochloric acid, after passing through, the filler paper, should give none of the reactions of the alkaline earths, while the paper should not blacken with ammonium sulphide, proving the absence of many of the metals nor should it be colored by a solution of salicylic acid, wbich would indi-... 

The Shell Chlorine Process. The catalyst developed by Shell consists of a mixture of copper(II) chloride and other metallic chlorides on a silicate carrier [202]. The reaction of the stoichiometric mixture of hydrogen chloride and air takes place in a fluidized-bed reactor at ca. 365 °C and 0.1-0.2 MPa. The yield is 75%. The water condenses out from the gas stream, and the hydrogen chloride is removed by washing with dilute hydrochloric acid. After the residual gas has been dried with concentrated sulfuric acid, the chlorine is selectively absorbed, e.g., by disulfur dichloride. After desorption and liquefaction, the chlorine has a purity > 99.95 %. 

The monazite sand is heated with sulfuric acid at about 120 to 170°C. An exothermic reaction ensues raising the temperature to above 200°C. Samarium and other rare earths are converted to their water-soluble sulfates. The residue is extracted with water and the solution is treated with sodium pyrophosphate to precipitate thorium. After removing thorium, the solution is treated with sodium sulfate to precipitate rare earths as their double sulfates, that is, rare earth sulfates-sodium sulfate. The double sulfates are heated with sodium hydroxide to convert them into rare earth hydroxides. The hydroxides are treated with hydrochloric or nitric acid to solubihze all rare earths except cerium. The insoluble cerium(IV) hydroxide is filtered. Lanthanum and other rare earths are then separated by fractional crystallization after converting them to double salts with ammonium or magnesium nitrate. The samarium—europium fraction is converted to acetates and reduced with sodium amalgam to low valence states. The reduced metals are extracted with dilute acid. As mentioned above, this fractional crystallization process is very tedious, time-consuming, and currently rare earths are separated by relatively easier methods based on ion exchange and solvent extraction. 

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