Modifications reduction

The executive knew she was in trouble when her salary underwent a modification reduction adjustment of 50 percent. 

The reductive amination process has been modified for the preparation of A-unsubstituted aminophosphonic acids (Scheme 5.88). ° Thus, the use of benzylamine in reaction with phosphonylated aldehydes increases chemospecificity, reaction rates, and yields. Aminobenzylphosphonates are isolated in yields of around 85% and then converted to aminoalkylphosphonates. Subsequent catalytic hydrogenation followed by acid hydrolysis and purification gives aminoalkylphosphonic acids.Together with its modifications, reductive amination is one of the most useful and general methods available for the preparation of a wide variety of aminoalkylphosphonic acids from phosphonylated aldehydes. 

Thus, substantial polymer molecular weight modification (reduction) is seen to be a consequence of deliberate stoichiometric reactant imbalance via MDI deficiency. This not only represents a method of thermoplastic polyurethane elastomer molecular weight control but also demonstrates what inadvertent reactant imbalance can do to the polymerization and the polymer product. 

The synthon (51) is derived from the optically active C22-allenic apocarotenal 49 which is prepared via a Wittig condensation of the Ci5-allenic aldehyde 23b with the Cv-skeleton phosphonium chloride 48 (Scheme 10). The compound 23b (97% e.e.) is synthesized starting from the TMS ether 47 of 36 through intermediates 4 and 31 according to the known route (Scheme 7), with minor modifications. Reduction of the aldehyde group in 49 (a mixture of (IIZ)- and (1 l )-isomers) with NaBH4, followed by acetylation, yields the acetate 50, which is converted into the sulphone 57 by heating under reflux with sodium sulphinate in propan-2-ol and water. 

The various 3-keto analogs also can be used to give regioselective modifications. Reduction of 3-ketosucrose with sodium borohydride exclusively gives al-losucrose [110] (reaction 4.105). Reaction of the keto group with hydroxylamine... 

Improving the cetane number by additives results in better engine behavior, as would be predicted by the combustion mechanisms in the diesel engine (noise reduction, better operating characteristics, particularly when cold). Nevertheless, concerning certain items such as pollution emissions, it may be better to obtain a higher cetane number rather by modification of the... 

In an effort to counteract the accuracy reduction of the impulse method in a resonance situation, a modification to the impulse method is proposed in [7]. There, the term is replaced by 17 ° (.4(2 )), where A x) represents... 

Method B (Huang - Minion modification of Wolff - Kishner reduction)... 

The procedure for the Clemmensen reduction is somewhat different from that previously described (Sections III,9, and IV,6) the chief modification of moment is the use of toluene. The concentration of organic material in the aqueous layer is considerably reduced this results in less high b.p. products being formed, thus leading to a better yield of a purer product,... 

Chapters 9, 10 and 11 describe methods for substitution directly on the ring with successive attention to Nl, C2 and C3. Chapters 12 and 13 are devoted to substituent modification as C3. Chapter 12 is a general discussion of these methods, while Chapter 13 covers the important special cases of the synthesis of 2-aminoethyl (tryptaminc) and 2-aminopropanoic acid (tryptophan) side-chains. Chapter 14 deals with methods for effecting carbo cyclic substitution. Chapter 15 describes synthetically important oxidation and reduction reactions which are characteristic of indoles. Chapter 16 illustrates methods for elaboration of indoles via cycloaddition reactions. 

Another modification of this process was reported in 1988 (84). In this process, a precondensate of THPC and urea, plus excess urea, are neutralized to a pH of about 5.7, and the buffer salt is added. The fabric is then given a standard pad-dry-cure process followed by oxidation and laundering. The principal advantage of this modification is a reduction in both formaldehyde vapors and phosphine-like odors released during processing (84). 

For the Verneuil growth of mtile and strontium titanate it is necessary to maintain strongly oxidizing conditions to prevent excessive reduction of TF+ to Tk+. This is achieved by adding a third outer tube carrying extra oxygen to the Verneuil torch (Fig. 1) in the tricone modification. Annealing in O2 at about 1100°C is subsequently used to achieve full oxidation. 

In the past, all grades of refined ferromanganese were made by various modifications of multistep silicon reduction processes. Depending on the carbon content desired in the product, a manganese ore and lime mixture was allowed to react with the silicon in silicomanganese or low carbon silicomanganese in an open, electric-arc furnace. The equilibrium reaction is... 

Ingredient Additions and Substitutions. Processed meat products have the greatest opportunity for fat reduction for modification because their composition can be altered by reformulation with a fat replacement (see Fat replacers). 

In the last few years several modifications to the traditional mixed acid nitration procedure have been reported. An adiabatic nitration process was developed for the production of nitrobenzene (9). This method eliminated the need to remove the heat of reaction by excessive cooling. The excess heat can be used in the sulfuric acid reconcentration step. An additional advantage of this method is the reduction in reaction times to 0.5—7.5 minutes. 

The Faux process is a modification of the Bechamp reaction that was discovered in 1854. It has been used for the reduction of nitrobenzene to aniline using metallic iron ... 

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