Cuprous arsenite

Nitrophenylarsonic acid has been prepared by heating p-nitrobenzenediazonium chloride with arsenious acid in hydrochloric acid, by the action of -nitrobenzenediazonium chloride on sodium arsenite, by the action of sodium arsenite on sodium -nitrobenzeneisodiazo oxide, by the diazotization of -nitro-aniline in acetic acid in the presence of arsenic chloride and cuprous chloride, and by the reaction of -nitrobenzenediazonium borofluoride with sodium arsenite in the presence of cuprous chloride. ... 

To estimate arsenite and arsenate when present together, the former may first be determined in a portion of the solution by titration with iodine in the presence of sodium bicarbonate. Another portion is acidified strongly with hydrochloric acid, some ferrous sulphate and potassium bromide are added and the whole of the arsenic is distilled off as chloride and collected in water.2 The reduction may also be accomplished by cuprous chloride.3 The arsenious acid in the aqueous distillate is determined as above and the arsenic acid found by difference. 

In general, the Rosenmund reaction is carried out by heating one mole of trisodium or tripotassium arsenite with one mole of aromatic halide in boiling aqueous ethanol solution. Certain minor modifications of this procedure have been employed. If the aromatic halide contains an addic group (e.g., o-bromophenylarsonic add), no ethanol is necessary.82 Copper powder, as well as cuprous chloride, is sometimes employed as catalyst, but the value of either is uncertain.82- 86 Reactions of bromo-benzene and p-br omo acetophepo ne must be run in sealed tubes at temperatures of 150-2000.88 87 82... 

Bart reaction. (Scheller modification Star-key modification). Formation of aromatic arsonic acids by treating aromatic diazonium compounds with alkali arsenites in the presence of cupric salts or powdered silver or copper in the Scheller modification, primary aromatic amines are diazotized in the presence of arsenious chloride and a trace of cuprous chloride. 

The preparation of this compound has been reported by Jacobs et al. [30] and by Ruddy and Starkey [31], An aqueous solution of 4-nitrobenzenediazonium boro-tetrafluoride (36) is treated with sodium arsenite in the presence of sodium hydroxide and cuprous chloride to give disodium 4-nitrobenzenearsonic acid, which is acidified with hydrochloric acid to afford nitrasone in 71-79% yields [31],... 

Copper is an essential element, being active in many enzymes and hemocyanin. Copper is an essential nutrient element to animals and plants. However, high Cu accumulation in animals and plants can be toxic. Copper is found in three oxidation states including cupric (+2), cuprous (+1), and elemental Cu (0). Cu+ and Cu + are the most important forms and are involved in oxidation-reduction reactions in soils and sediments (Figure 12.7). Cu+ and Cu + can exist in aqueous systems, although the latter is much more dominant. Copper is widely distributed in nature in its elemental state and in the form of sulfide, arsenite, chloride, and carbonates. The earth s crust on an average contains approximately 50 ppm copper. Soil and sediment contain approximately... 

This reaction was first reported by Bart in 1910. It is the synthesis of arylarsenic acids from aromatic diazonium compounds with alkali arsenites in the presence of cupric salts, powdered silver, or copper. Therefore, this reaction is generally known as the Bart reaction. In addition, the reaction between aromatic diazonium and arsenious chloride in the presence of trace amounts of cuprous chloride is referred to as the Scheller modification. Besides the Scheller modification, the Sakellarios modification is the reaction between sulfanilamide and phenyldisodium arenite. ... 

---