Arsonic acids, aromatic, preparation

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 ... 

In general, primary aromatic amines can be converted into the corresponding arsonic acids by the Bart reaction or by one of its modifications. This method has been used to prepare arsonic acids of the benzene, naphthalene, fluorene, and anthraquinone series as well as of a number... 

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... 

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

Aromatic arsonic acids are generally prepared by the Bart reaction from an aromatic diazonium salt and sodium arsenite ... 

The Bart reaction is successful with a wide variety of aromatic and heterocycHc amines. A variation in which an aromatic amine, in the presence of arsenic trichloride, is dia2oti2ed in an organic solvent (the ScheUer reaction) has also found wide appHcation. Both arsonic and arsinic acids can be prepared by the ScheUer reaction which often gives better yields than the Bart reaction with electron-attracting substituents on the aromatic ring. For the commercial preparation of 4-aminophenylarsonic acid [98-50-0] (arsaniUc acid), C HgAsNO, and 4-hydroxyphenylarsonic acid [98-14-6] C H AsO, the Bnchamp reaction is used ... 

The Preparation op Aromatic Arsonic and Arsinic Acids by the Bart, Bechamp, and Rosenmund Reactions—Cliff S. Hamilton and Jack F. Morgan 415... 

Baeyer-Villiger oxidation of alkyl- and aryl-substituted C -C, cycloalkanones, steroid ketones and branched chain aliphatic ketones is catalysed by arsonated polystyrene resins [53], Larger size cycloalkanones and linear ketones react much slower. Water miscible and immiscible solvents can be used. With the latter, the resin behaves as an effective catalyst and a phase-transfer agent (triphase catalysis). The same compounds are also epoxidation catalysts. More recently, a method for the preparation of phenols by the oxidation of aromatic aldehydes and ketones has been reported. The most convenient catalysts are nitro-substituted arylseleninic acids and corresponding diselenides [54]. 

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