Arsonous acid esters

These As-O bonded species are related by the fact that they contain arsenic in the +3 oxidation state and have one organo substituent bonded to the arsenic. The general formulas are as follows arsonous acids, RAs(OH)2 arsonous acid anhydrides, RAsO arsonous acid esters, RAs(OR )2-... 

By analogy with the arsonous acid esters, the arsinous acid esters form in the reaction of monohaloarsines with sodium alkoxides (equation 134). The alcoholysis of the diarsoxanes in the presence of copper sulfate also produces arsouous acid... 

Arsonic acid ester Pyrolysis temperature (°C) Pyrolysis product Reference... 

The pyrolysis of arsonic acid esters results in low yields of arsenic(III) esters. 

Condensation of the bis(2-aminoethyl)arsonous acid ester (126) with acetylacetone in the presence of a trace of formic acid gave (127) in 58% yield <87CZ273>. 

Arsonous acid esters from arsine oxides... 

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... 

More recently, studies were undertaken to recover tin from gravity tailings at the San Rafael tin mine in Peru. During these studies, a highly effective collector mixture [5] consisting of succinamate phosphoric ester and sodiumhylenesulponate was established. This mixture was more effective than sulphosuccinamate alone, or arsonic acid. 

Chemical Name 3-Hydroxypropylene ester of 3-acetamido-4-hydroxydithiobenzene-arsonous acid... 

A very closely related type of spiro-oxyarserane, (102-106j7nas been synthesized124 by an extension of the known reactions of tetracoordi-nated arsenic compounds, namely, the reaction of arsenic and arsonic acids and esters with glycols.128... 

It has already been noted that the esters of arsinous and arsonous acids disproportionate of heating. The formation of As(OR)3 in the pyrolysis of arsonic acid derivatives is thought to be the product of the secondary disproportionation reaction of the primary product RAs(OR)2-... 

The pyrolysis of organoarsenic compounds containing the arsenyl moiety has some limited preparative applications [arsenyl (As=0) by analogy with phosphoryl (P=0)]. The compounds are based on the arsonic acid RAs(0)(0H)2, the arsinic acid R2As(0)0H and the arsine oxide R3As=0 structures. The acids are in interesting contrast with the phosphorus series. The phosphonic and phosphinic esters are prepared from the phosphorus(III) precursors via the Arbuzov synthesis. This synthetic route fails with the arsenic analogues, and further, if an alkyl halide or a salt is added in the pyrolysis of arsonic or arsinic acid esters a retro-Arbuzov reaction takes place . ... 

Spirocyclic structures (98) have been assigned to the esters produced from glycols and aryl- or alkyl-arsonic acids.672... 

The reaction of 1,2-xylylenedithiol with ar enic(III) halides and various dialkyl esters of aryl-arsonic acids under anhydrous conditions gives the corresponding halo- or aryl-substituted dithi-arsepins (112), respectively <88izvi82>. As found for the analogous dioxarsepins, halo substituents reduce conformational lability. 

I.r. and Raman data for methyl- and ethyl-arsonic acids RAsOgHg are discussed in terms of Q symmetry for the skeleton, and strong peaks at 2820 and 2350 cm i indicate that fairly strong hydrogen-bond formation occurs. Data are also given for the alkali-metal salts and the methyl and ethyl esters. The presence of a skeleton with C, symmetry is also the basis for... 

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]. 

A number of esters of arsonic and arsinic acids have been prepared. One method involves the oxidation of dialkyl alkylarsonites with selenium dioxide ... 

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