Anhydrone

Two absorbents are required, one for water vapour, the other for carbon dioxide. The absorbents for water vapour which are generally employed are (a) anhydrous calcium chloride (14-20 mesh), (b) anhydrous calcium sulphate ( Drierite or Anhydrocel ), and (c) anhydrous magnesium perchlorate ( Anhydrone ). Both (b) and (c) are preferable to (a) (c) absorbs about 50 per cent of its weight of water, but is expensive. Anhydrous calcium chloride usually contains a little free lime, which will absorb carbon dioxide also it is essential to saturate the U-tube containing calcium chloride with dry carbon dioxide for several hours and then to displace the carbon dioxide by a current of pure dry air before use. 

Uses.. Anhyd Mg perchlorate has found widespread use as a drying agent under the trade names Anhydrone and Dehydrite. This use has been reviewed in a book by G.F. Smith (Ref 6). 

The use of the perchlorate as desiccant in a drybag where contamination with organic compounds is possible is considered dangerous [1], Magnesium perchlorate ( Anhydrone ) was inadvertently used instead of calcium sulfate (anhydrite) to dry an unstated reaction product before vacuum distillation. The error was realised and all solid was filtered off. Towards the end of the distillation, decomposition and an explosion occurred, possibly owing to the presence of dissolved magnesium perchlorate, or more probably to perchloric acid present as impurity in the salt [2]. 

As known (Addison and Logan 1964), anhydrons nitrates exhibit oxidizing properties. Their oxidizing activity increases from ionic nitrates with alkali and alkali-earth metal cations to covalent nitrates with transient metal cations. Oxidation reactions result in the formation of nitrogen-containing oxides. Depending on the kind of a nitrate salt and reaction conditions, one of these oxides can be predominant. Organic snbstrates can evidently serve as reductant. 

H-l,3-ditellurole. Under an atmosphere of argon, 0.23 g (2.4 mmol) of trimethylsily-lacetylene are dissolved in 5 mL dry tetrahydrofuran. The solution is cooled to -70°C. n-Butyl lithium (1.0 mL, 2.4 M, 24 mmol) is dropped into the stirred solution. Then 0.20 g (2.0 mmol) of tellurium powder is added. The mixture is warmed to 20°C and kept at this temperature for 2 h. To this mixture, cooled again to -70°C, is added a solution of 0.35 g (2.0 mmol) of chloroiodomethane in 1 mL of tetrahydrofuran. The mixture is stirred for 15 min and then quenched with 50 mL water. The product is extracted with three 15 mL portions of dichloromethane. The combined extracts are washed with brine, dried with anhydrous sodium sulphate and filtered. The filtrate is concentrated to give trimethylsilylethynyl chloromethyl tellurium as a pale-yellow oil. Tellurium powder (0.125 g, 1.0 mmol) is added to 2 mL of a 1 M solution (2.0 mmol) of lithium triethylborohydride in ethanol. The mixture is stirred at 20°C for 2 h under an atmosphere of argon. Then 2 mL of 1 M sodinm ethoxide in ethanol are added followed by 0.27 g (1.0 mmol) of trimethylsilylethynyl chloromethyl tellurium dissolved in 2 mL dimethylformamide. The mixture is stirred for 15 h at 20°C, then diluted with 25 mL water and extracted with three 15 mL portions of dichloromethane. The combined extracts are dried with anhydrons sodinm snlphate, fdtered and the filtrate concentrated. The residue is chromatographed on silica gel with hexane/dichloromethane (1 1) as mobile phase. The fractions containing the prodnct are concentrated and recrystallized from methanol 65% yield, m.p. 85°C. 

Synonyms of this drug are diampres, cyclotheriam, anhydron, and others. 

Formula Mg(C104)2 MW 223.21 forms several hydrates including a stable hexahydrate, Mg(C104)2 6H2O Synonyms Anhydrone Dehydrite... 

Synonym Amyl Nitrite Iso-Amyl Nitrite Amyl Sulthydrate Amyl Thioalcohol N-Amyltrichlorosilane Anesthesia Ether Anhydrone... 

MAGNESIUM PERCHLORATE Anhydrone, Dehydrlte, Magnesium perchlorate, anhydrous, Magnesium perchlorate hexahydrate Oxidizing Materisl, II 1 0 0 oxy... 

Dehydrite or Anhydrone should not be used because of the danger of sulfuric acid spraying into it. Drierite is much more efficient than calcium chloride. 

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