Medicines Magnesium compounds

Some magnesium compounds are important over-the-counter medicines. For example, milk of magnesia is a suspension of magnesium hydroxide (Mg[OH]2) in water. This creamy liquid suspension is used as an antacid to neutralize excess acid in the stomach. Another magnesium compound remedy is Epsom salts, which are used to treat certain skin rashes. Discovered in Epsom, England, in 1618, these are crystals of magnesium sulfate evaporated from water. 

Optically active 3-amino-2-hydroxycarboxylic acid derivatives are often key components of medicinally important compounds. The synthesis of isopropyl (2i ,35)-3-amino-4-cyclo-hexyl-2-hydroxybutyrate (126) (Scheme 28) takes advantage of a [2 + 2]-cycloaddition reaction of the chiral imines 123, prepared from 63, to assemble the important diastereomeric azetidinone 124 as the crucial precursor for completion of this novel synthesis. Protection of the hydroxy group of 63 as either the TBS ether 119 or the tert-buty ether 120, followed by a DIBAL reduction at —78 °C, produces smoothly one of the aldehydes 121 or 122. Condensation of these aldehydes with either di-p-anisylmethylamine or benzylamine in the presence of anhydrous magnesium sulfate affords the four possible chiral imines 123a—d (Scheme 26). 

Because of its extreme insolubiUty, barium sulfate is not toxic the usual antidote for poisonous barium compounds is to convert them to barium sulfate by administering sodium or magnesium sulfate. In medicine, barium sulfate is widely used as an x-ray contrast medium (see Imaging TECHNOLOGY X-RAY technology). It is also used in photographic papers, filler for plastics, and in concrete as a radiation shield. Commercially, barium sulfate is sold both as natural barite ore and as a precipitated product. Blanc fixe is also used in making white sidewall mbber tires or in other mbber appHcations. 

Magnesium-containing compounds are often common everyday medicines. What makes milk of magnesia an effective antacid ... 

Interestingly, in a situation where either magnesium stearate or stearic acid forms a component in the formulation, the organic medicinal compound which is acidic (amobarbital) cannot be extracted with NaOH solution for obvious reason that sodium stearate shall also be extracted along with the salt of the organic acid. Therefore, instead a saturated solution of Ba(OH)2 is employed thereby the insoluble precipitate of barium stearate may be discarded by filtration. 

In addition to the use of chlorine as an antiseptic for swimming pools and drinking water, large amounts are used during industrial processes that produce paper, plastics, textiles, dyes, medicines, insecticides, solvents, and some paints. Following are some of the more important compounds of chlorine used in industries hydrochloric acid (HCl + H O), table salt (NaCl), chloroform (CHCL ), carbon tetrachloride (CCy, magnesium chloride (MgCl ), chlorine dioxide (CIO ), potassium chloride (KCl), and lithium chloride (LiCl). 

Magnesium bromide occurs in sea water, surface and subterranean brines, and salt deposits. It is an electrolyte component in certain dry cells. In medicine, it is a sedative and anticonvulsant for treatment of nervous disorder. It also is used in organic synthesis forming several addition compounds. 

Aluminium oxide is the oldest ceramic material used in medicine. Bauxite and corundum are the main natural sources of aluminium oxide. Bauxite is a mixture of diaspore, gibbsite, iron hydroxides, clay minerals and quartz. It is formed by the tropical weathering of silicate rocks during which quartz and the elements sodium, calcium, magnesium and potassium are largely washed away. This is the reason why the remaining material becomes richer in the resistant elements titanium, iron and aluminium. The latter is extracted from this mixture in the form of aluminium hydroxide. In its turn this compound is converted into aluminium oxide by heating the mixture to 1200-1300 °C, this is called calcination. The hydroxide is thus made anhydrous. 

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