Arsinic acids R2AsO

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 ... 

Similar reactions on alkyl or aryl arsonites yield the arsinic acids R2AsO(OH) and Ar2AsO(OH). Arsine oxides are made by alkaline hydrolysis of R3ASX2 (or Ar3AsX2> or by oxidation of a tertiary arsine with KMn04, H2O2 or I2. 

E. Reduction of Arsinic Acids, R2AsO(OH), R = Alkyl, Aryl. 470... 

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