Arsonic acids synthesis

Rosenmund reaction for synthesis of arsonic acids, 2, 10 Rosenmund reduction, 4, 7... 

Several methods are available for the synthesis of cycloarsoxanes (a) hydrolysis of organoarsenic(III) dihalides RASX2 (X = Cl, Br, I), (b) reduction of arsonic acids RAsO(OH)2 and (c) oxidation of primary arsines RASH2 or cyclopolyarsines (RAs) . The tetramer cyclo-(MeAsO)4 exhibits the boat-chair conformation, whereas the mesityl derivative cyclo-(MesAsO)4 adopts the crown conformation (Figure 11.24). The As-O bond distances are in the range 1.77-1.82 A, typical for single bonds. 

A related synthesis of the C—As bond was used (106) in the synthesis of the natural compound (see 6) trimethylarsonioacetate, Me3As+— CH2—COO", by treating ethyl bromoacetate with trimethylarsine. Although this reaction has not been used to make arsonic acids, it could conceivably be adapted for this by replacing the methyl groups with more labile alkyl groups. 

In the Rosenmund synthesis salts of arsonic acids are obtained by treatment of aryl halides with sodium or potassium arsenite.8... 

It was not until thirty-eight years later that this method of synthesis was applied to the aromatic series. Rosenmund,8 in 1921, prepared phenyl-arsonic acid (in low yield) and o-carboxyphenylarsonic acid (44% yield) from tripotassium arsenite and bromobenzene and o-bromobenzoic acid, respectively. Since that time only one other arsonic acid, o-phenylene-diarsonic acid,29 82 has been obtained in good yields by Rosenmund s method. From two other aromatic bromides, p-bromobenzoic add and... 

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 . ... 

Serves SV, Tsivgoulis GM, Sotiropoulos DN, loannou PV, Jain MK (1992) Synthesis of (R)-and (S)-l, 2-diacyloxypropyl-3-arsonic acids optically active arsonoKpids. Phosphorous Sulfur Silicon 71 99-105... 

The synthesis of arsonic acids by the Bart reaction is a domain of classical arsenic chemistry (Section 6.26.4.1.3.1.1), for example (22) (23) (Scheme 2) <22LA(429)55> (see also <1863CR(56)1172, 21CB438, 25BRP261026)). 

The main application of mercury derivatives has been to the synthesis of heterocyclic arsenicals. Thus diphenylene oxide-1-arsonic acid and pyridyl-3-arsonic acid have been isolated following oxidation of the initial reaction products obtained from arsenic trichloride and the appropriate heterocyclic mercury chloride 114,115). Furan and thiophene derivatives have been similarly prepared 116,117,118). 

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