Green Reagent

Before coupling, excess nitrous acid must be destroyed. Nitrite can react with coupling components to form nitroso compounds causiag deHterious effects on the final dyestuff. The presence of nitrite can be detected by 4,4 -diamiQO-diphenyHnethane-2,2 -sulfone [10215-25-5] (Green reagent) or starch—iodide. Removal of nitrite is achieved by addition of sulfamic acid or urea [57-13-6], however, sulfamic acid [5329-14-6] has been more effective ia kinetic studies of nine nitrous acid scavangers (18). 

MACB = 5-chloro-2-(methylamino)benzo-phenone 227 Macrolide antibiotics 195 Magnesium cations 144,145, 311, 312 Malachite green reagent 45 Malathion 362... 

Hydrogen peroxide is the ultimate green reagent because water is the only by-product, so no inorganic salts are produced in its reaction. 

In conclusion, we reiterate that photoinitiated reactions have a dramatic advantage with respect to thermal reactions, since light is the green reagent par excellence. If we consider the possibihty that such reactions will be apphed in the foreseeable future, and in particular whether they will contribute to the development of green chemistry, we can conclude that there are both indisputable advantages and difficult to solve problems. 

Industry, in fact, has a major interest in these diesters as building blocks for nylon 6,6 and nylon 7,7 in the production of polyesters and polyamides. However, their present synthesis raises an environmental concern. For instance, the oxidation of cyclohexanone by nitric acid (for the preparation of adipic acid), accounts for more than 10% of the total yearly release of N2O, which is among the main gases responsible for the greenhouse effect. The reaction of Scheme 4.14 represents an eco-friendly alternative synthesis of a,(i)-diesters which uses green reagents and, relevantly, has a 100% atom economy. The overall process is mechanistically described as a retro-Claisen condensation. 

III) compounds are especially attractive as green reagents and catalysts for organic synthesis. Bismuth(III) compounds are remarkably nontoxic, relatively air and moisture stable, and easy to handle. The contributions from our laboratory in the last 5 years in the field of applications of bismuth(III) compounds as catalysts are presented. 

We must define goals for green research and to consider evaluation criteria for green reagents. 

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