Arsonic adds

The BiochemicEil Action of Arsonic Adds EspeciEilly as Phosphate Ansilogues Henry B. F. Dixon... 

Three methods for the preparation of aromatic arsonic adds are de- scribed in this review. By far the most widely applicable of these is the Bart reaction, which involves the interaction of a diazonium salt with an inorganic arsenic compound. In the original Bart process 1 and most of its modifications an alkali arsenite is used, as shown in the following equation. 

Alkyl Groups. As expected, all three toluidines give toluenearsonic acids in good yields (45-55%). From the o-, m-, and p-aminobenzyl alcohols the corresponding arsonic adds result in yields of 12-20%.2S When the reaction is applied to 2-hydroxy-4-mtro-5-alkylanilines,24 the yield of arsonic acid decreases as the length of the side chain is increased. o-Butylphenylarsonic acid is obtained by the Bart method in only a 12% yield.26 "... 

Nitro Groups. Nitroanilines are converted to the corresponding arsonic adds in the following yields ... 

When o-iodoaniline is subjected to the Bart reaction two products result, o-phenylenediarsonic add in 20% yield, together with a lesser amount of o-iodophenylarsonic acid.29 The o-iodophenylarsonic acid first formed reacts with another molecule of sodium arsenite (Rosenmund reaction) to produce the diarsonic acid. The conversion of 2,4-, 2,5-, and 3,4-dichloroaniline to the corresponding arsonic adds takes place in yields of 60-70%.88... 

Sulfo and Sulfamido Groups. It has been shown that sulfanilic acid can be converted into p-sulfophenylarsonic acid (25-45%).49 60 By the ordinary Bart reaction p-sulfamidophenylatsonic acid (25%) may be prepared,60 although a better yield (57%) is obtained by a modified Scheller reaction.18 Apparently, metanilic acid and naphthionic acid will not yield the corresponding arsonic adds.18 61 Although m-sulfamido-phenylarsonic add is not available by the usual procedure it can be prepared in a 58% yield by the method of Scheller.18... 

General Experimental Procedure. A mixture of the amine, 0.1 mole in 250 cc. of absolute alcohol, with 10 g. of sulfuric acid and 28 g. of arseni-ous chloride, cooled to 0°, is diazotized with a saturated aqueous solution of the calculated amount of sodium nitrite (starch-iodide end point). Then, and not before, 1 g. of cuprous bromide is added the mixture is thoroughly stirred, warmed to 60° until no more nitrogen is evolved, and then distilled with steam. The separated arsonic add is recrystallized. 

Meyer,81 in 1883, developed a very interesting and useful method of preparing aliphatic arsonic adds from alkyl halides and. trisodium arsemte... 

The electrochemistry of the mono addic analogues of arsonic adds, the arsinic acids, has been explored to a much smaller extent than that of the arsonic acids (Section II.D). This is despite the fact that dimethylarsinic add (cacodylic acid), and especially its... 

With regard to the mechanism, Jacobson et td. proposed that the arsonic acid catalyst is transformed to the perarsonic add by hydrogen peroxide, the perarsonic add being the active oxidant (Scheme 4.5) [29]. This may well be the case for arsonic add-catalyzed epoxidations performed in 1,4-dioxane as solvent When using fluorinated alcohols as solvent, we believe that reversible ester formation is involved in the mechanism (Scheme 4.7). This assumption is based on ESI-MS studies of the reaction mixtures [23]. 

Preparative aspects. Since bonds between carbon and arsenic, antimony and bismuth are stable to water they may be made in aqueous solution. Thus, alkyl arsonic adds RAs(OH)2 may be prepared by the Meyer reaction between sodium arsenite and alkyl halides ... 

Dihydro-3-methyl-5-oxo-l-phenyl- D-00439 l -pyrazol-4-yl)azo phenyl arsonic add, 9CI... 

Arsonic adds. Benzenearsonlc aold precipitates uranium (IV) In a weakly acidic solution, pH 1-3. Tltanlxan and cerium (IV) are partially precipitated. Thorium, zirconium, hafnium, tin (IV), nlobltun, and tantalum are qumtltatlvely precipitated. 

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