Arsenious acid esters

Arsenious oxide is soluble in a number of organic liquids. Thus, 100 parts of absolute alcohol dissolve at 15° C. 0-025 part, and at boiling point 3-402 parts of the octahedral form. The solubility is increased by the addition of water. The vitreous modification dissolves to the extent of 1-060 parts per 100 at 15° C. and addition of water decreases the solubility. Esters of arsenious acid may be obtained by heating, with stirring, a mixture of the oxide and an alcohol in the presence of a hydrocarbon such as benzene, toluene or xylene.7... 

Formic and oxalic acids and their salts in the presence of mineral acid reduce arsenic acid and arsenates the reaction is accelerated by boiling.10 Tartaric acid does not appear to form complexes with arsenic acid 11 such as are formed with arsenious acid. Certain sugars, namely fructose and less rapidly sucrose, but not glucose, maltose or lactose, form labile esters of arsenic acid during fermentation in the presence of this acid the reaction is purely a chemical one and not biochemical.12... 

Catalysts having a very acid nature such as metaphosphoric acid, arsenious acid, boric acid, or salts of these acids have been proposed. The addition of copper as such or as the formate serves to promote the reaction.190 Reaction chambers extremely resistant to corrosion must be tised. Catalysts such as zinc arsenite. or zinc or chromium metaphosphatc having a highly acidic nature are claimed to be effective in the formation of organic acids from carbon monoxide and alcohols at temperatures of about 300° C. and a pressure of 200 atmospheres. Even with such acidic catalysts considerable quantities of esters are stated to be formed.101... 

Other methods which have been used for preparing these esters of substituted arsenious acids are illustrated by the following processes 333, 335, 338, 339, 340) ... 

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