Arsonic acid

0 metal constants were also reported but are not included in the 

Other references 60DA,61GK, 66NV,66RS 

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Arylarsonic acids have usually a very low solubility in cold water. They are however amphoteric, since with, for example, sodium hydroxide they form sodium salts as above and with acids such as hydrochloric acid they form salts of the type [CaHjAsCOHljlCl. Both types of salt are usually soluble in water, and to isolate the free acid the aqueous solution has to be brought to the correct pH for most arsonic acids this can be achieved by niaking the solution only just acid to Congo Red, when the free acid will usually rapidly separate. 

Arsonic acids, like carboxylic and sulphonic acids (pp. 349, 353), usually give crystalline benzylthiouronium salts. Add just sufficient dilute aqueous sodium hydroxide dropwise with shaking to a suspension of 0 5 g. of phenylarsonic acid in 10 ml. of water to give a clear solution. Then add 0 5 g. of benzylthiouronium chloride dissolved in 10 ml. of water. Filter off the precipitated benzylthiouronium salt, wash with water and dry m.p. 114-117° it tends to dissociate on attempted recrystallisation. 

The conversion of an aromatic diazonium compound into the corresponding arsonic acid by treatment with sodium arsenite in the presence of a catalyst, such as copper or a copper salt, is called the Bart reaction. A modification of the reaction employs the more stable diazonium fluoborate in place of the diazonium chlorid.i. This is illustrated by the preparation of />-nitrophenylarsonic acid ... 

Acetarsone. Acetarsone (3-acetamido-4-hydroxyphenyl arsonic acid) (13), also known as acetarsol, stovarsol, and Ehrlich 594, forms white prisms from water. 

Good yields of phenylarsine [822-65-17, C H As, have been obtained by the reaction of phenylarsenic tetrachloride [29181-03-17, C H AsCl, or phenyldichloroarsine [696-28-6], C3H3ASCI25 with lithium aluminum hydride or lithium borohydride (41). Electrolytic reduction has also been used to convert arsonic acids to primary arsines (42). Another method for preparing primary arsines involves the reaction of arsine with calcium and subsequent addition of an alkyl haUde. Thus methylarsine [593-52-2], CH As, is obtained in 80% yield (43) ... 

A large number of polymeric substances, (RAs) or (ArAs), are also known (113). They are usually prepared by the reduction of arsonic acids with hypophosphorous acid (100,114) or sodium dithionite (115). Most of these polymers have not been well characterized. An insoluble, purple material, poly(methylarsinidene) [26403-94-1], (CH As), prepared by the interaction of methylarsine and a dihalomethylarsine, however, has been shown by an x-ray investigation to have a ladderlike polymeric stmcture in which the inter-mng distances correspond to one-electron bonds (116) ... 

Arsonic and Arsinic Acids. The arsonic acids, compounds of the type RAsO(OH)2, are among the most important organic arsenicals. The ahphatic arsonic acids are generally prepared by the Meyer reaction ie, heating an alkyl haUde with As O in alkaline solution ... 

Where X is Br or Q, the free acids may be obtained by acidification of the alkaline solution, but where X is I, the acids must be isolated as salts to avoid reduction of the arsonic acids by HI. Rather than using alkyl haUdes, alkyl or dialkyl sulfates or alkyl arenesulfonates can be used. Primary alkyl haUdes react rapidly and smoothly, secondary haUdes react only slowly, whereas tertiary haUdes do not give arsonic acids. AHyl haUdes undergo the Meyer reaction, but vinyl hahdes do not. Substituted alkyl haUdes can be used eg, ethylene chlorohydrin gives 2-hydroxyethylarsonic acid [65423-87-2], C2H2ASO4. Arsinic acids, R2AsO(OH), are also readily prepared by substituting an alkaU metal arsonite, RAs(OM)2, for sodium arsenite ... 

A better method involves the use of silver salts of arsonic acids ... 

Carbarsone (Amebarsone) was once widely used for the treatment of intestinal amebiasis. Like other arsonic acids, however, carbarsone may cause skin rashes and even damage to the vision. Although it is stiU available for medicinal use, it is really obsolete as an amebicide because less toxic and more effective nonarsenicals are now available (174). 

More extensive catenation occurs in the cyc/o-polyarsanes (RAs) which can readily be prepared from organoarsenic dihalides or from arsonic acids as follows ... 

Arsonic acids RAsO(OH)2 are amongst the most important organoarsonium compounds. Alkyl arsonic acids are generally prepared by the Meyer reaction in which an alkaline solution of AS2O3 is heated with an alkyl halide ... 

Aryl arsonic acids can be made from a diazonium salt by the Bart reaction ... 

Triazolo[4,5-/i]quinoline 143 and triazolo[4,5-/i]quinoline-5-arsonic acid 144 were isolated from mother liquors after reduction and bis-diazotization of 5,7-dinitro-8-(4-toluenesulfone)aminoquinoline in the presence of cupric sulfate with trisodium arsenite (32JCS2196). 

Arsinsaure, /. arsonic acid, arsinic acid (better translated arsonic acid when referring to compounds of the formula RAsO(OH)a). Art,/, kind, sort, type, species, variety nature manner, way race, breed pi, manners (Biol.) species. (Used as a suffix to give a generic meaning as, Pecharten, pitches, kinds of pitch.)... 

C14H14CINO4 3412-99-5) see Chloroquine (4-chlorophenyl)arsonic acid (C(,H(,AsC10, 5440-04-0) see Acetarsol a-chloro-u-phenylbenzeneacetic acid l-methyI-4-piperidi-nyl ester... 

Concerning anthropogenic sources, methyl arsenic compounds such as methyl arsonic acid and dimethylarsinic acid have been used as herbicides, and were once a significant source of environmental residues. Dimethyl-arsinic acid (Agent Blue) was used as a defoliant during the Vietnam War. 

Hydroxy-3,5-dinitrobenzene arsonic acid 1-Nitrobutane (iii) Ammonium nitrate... 

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