Additional examples

The following additional examples of cognate preparations are given ... 

The proeedure used here to form the i S state illustrates point 3 in the above preseription for determining wavefunetions. Additional examples for eonstrueting wavefunetions for atoms are provided later in this ehapter and in Appendix G. 

As with the atomic systems, additional examples are provided later in this chapter and in Appendix G. 

These Pd-catalysed procedures appear to be preferable to earlier ones in which Cu(I)[3] or Hg(II)[4] were used to induce cyclization. Some additional examples are given in Table 2.3. 

Another category Ic indole synthesis involves cyclization of a-anilino aldehydes or ketones under the influence of protonic or Lewis acids. This corresponds to retro.synthetic path d in Scheme 4.1. Considerable work on such reactions was done in the early 1960s by Julia and co-workers. The most successful examples involved alkylation of anilines with y-haloacetoacetic esters or amides. For example, heating IV-substituted anilines with ethyl 4-bromoacetoacetate followed by cyclization w ith ZnClj gave indole-3-acetate esterfi]. Additional examples are given in Table 4.3. 

Problems 12 2 12 3 and 12 7 offer additional examples of reactions in which only a sin gle product of electrophilic aromatic substitution is possible... 

You will come across numerous examples of qualitative and quantitative methods in this text, most of which are routine examples of chemical analysis. It is important to remember, however, that nonroutine problems prompted analytical chemists to develop these methods. Whenever possible, we will try to place these methods in their appropriate historical context. In addition, examples of current research problems in analytical chemistry are scattered throughout the text. 

Sources providing additional examples of inorganic and organic gravimetric methods include the following texts. 

The titration curve in Figure 9.1 is not unique to an acid-base titration. Any titration curve that follows the change in concentration of a species in the titration reaction (plotted logarithmically) as a function of the volume of titrant has the same general sigmoidal shape. Several additional examples are shown in Figure 9.2. 

A good source for additional examples of the application of all forms of titrimetry is... 

Few potentiometric biosensors are commercially available. As shown in Figures 11.16 and 11.17, however, available ion-selective and gas-sensing electrodes may be easily converted into biosensors. Several representative examples are described in Table 11.5, and additional examples can be found in several reviews listed in the suggested readings at the end of the chapter. 

In most cases, the references include additional examples of the class alcohols. Nitroalkyl esters are known (6—7). 

Molten cryohte dissolves many salts and oxides, forming solutions of melting point lower than the components. Figure 1 combines the melting point diagrams for cryolite—A1F. and for cryohte—NaF. Cryohte systems ate of great importance in the HaH-Heroult electrolysis process for the manufacture of aluminum (see Aluminumand ALUMINUM alloys). Table 5 Hsts the additional examples of cryohte as a component in minimum melting compositions. 

A spectacular example of selective deliydiogenation in the steroid ring system (42) has been attributed to stereoelectronic effects (31) the yield is 80%. Several related steroids also show this chemistry. An extensive review containing many additional examples and a mechanistic discussion is available (23). 

Acid-Gatalyzed Synthesis. The acid-catalysed reaction of alkenes with hydrogen sulfide to prepare thiols can be accompHshed using a strong acid (sulfuric or phosphoric acid) catalyst. Thiols can also be prepared continuously over a variety of soHd acid catalysts, such as seoHtes, sulfonic acid-containing resin catalysts, or aluminas (22). The continuous process is utilised commercially to manufacture the more important thiols (23,24). The acid-catalysed reaction is commonly classed as a Markownikoff addition. Examples of two important industrial processes are 2-methyl-2-propanethiol and 2-propanethiol, given in equations 1 and 2, respectively. 

Additional examples have been reported (5). Disperse dyes which contain an oxazine ring include the yeUow 1,3-dinitro-lOhd-phenoxazine... 

Additional examples of color centers are old Mn-containing glass turned purple by irradiation with the mechanism + e even... 

Enzyme Sta.bihty, Loss of enzyme-catalytic activity may be caused by physical denaturation, eg, high temperature, drying/freezing, etc or by chemical denaturation, eg, acidic or alkaline hydrolysis, proteolysis, oxidation, denaturants such as surfactants or solvents, etc. pH has a strong influence on enzyme stabiHty, and must be adjusted to a range suitable for the particular enzyme. If the enzyme is not sufficiendy stable in aqueous solution, it can be stabilized by certain additives a comprehensive treatment with additional examples is available (27). 

Such groups a to a pyridine-like nitrogen atom are expected to undergo Michael additions. Examples are known in the imidazole series. 

Additional examples of acid- and base-catalyzed reactions of this type are giveh 1ft equations (23)-(32). 

A 1 1 adduct from diphenylsulfilimine and a benzoylacetylene underwent an intramolecular cyclization reaction to give an isoxazole in good yield (equation 40). Similarly, the 1 1 adduct from iodoazide and chalcone gave 3,5-diphenylisoxazole (equation 41). These two approaches to regiospecific isoxazole synthesis are of little practical significance. Additional examples of the (OCCCN) reaction are given in equations (42) and (43). 

The intermediate sulfenic acid derived from a penicillin sulfoxide has been trapped by a large assortment of reagents and, in one case, the sulfenic acid itself has been isolated (74JA1609). Only some of these products will be discussed here, and the reader is referred to the cited reviews (especially B-80MI51102) for additional examples. 

Appleton and Waddington [40] present experimental evidence that pulse duration also affects residual strength in OFHC copper. Samples shock loaded to 5 GPa for 1.2 ps pulse duration exhibit poorly developed dislocation cell structure with easily resolvable individual dislocations. When the pulse duration is increased to 2.2 ps (still at 5 GPa peak stress) recovered samples show an increase in Vickers hardness [41] and postshock electron micrographs show a well-developed cell structure more like samples shock loaded to 10 GPa (1.2 ps). In the following paragraphs we give several additional examples of how pulse duration affects material hardness. 

This type of severe air pollution damage has occurred several times in the past. If care is not taken, additional examples will be documented in the future. 

This chapter provides examples of these strategies, and the process life cycle discussions in Chapters 4 through 6 include additional examples. 

Section 4.3 on Process Development includes additional examples of opportunities for process minimization or intensification, including ... 

An additional example of Eq. (2.2) is the distribution function commonly used in solvent extraction ... 

Monomeric thiazyl halides can be stabilized by coordination to transition metals and a large number of such complexes are known (Section 7.5). In addition, NSX monomers undergo several types of reactions that can be classified as follows (a) reactions involving the n-system of the N=S bond (b) reactions at the nitrogen centre (c) nucleophilic substitution reactions (d) halide abstraction, and (e) halide addition. Examples of each type of behaviour are illustrated below. 

A kinetic scheme that is fully consistent with experimental observations may yet be ambiguous in the sense that it may not be unique. An example was discussed earlier (Section 3.1, Consecutive Reactions), when it was shown that ki and 2 in Scheme IX may be interchanged without altering some of the rate equations this is the slow-fast ambiguity. Additional examples of kinetically indistinguishable kinetic schemes have been discussed.The following subsection treats one aspect of this problem. 

C. Other Methods of Enamine Formation O. Additional Examples of Enamine Formation... 

An enamine was obtained in the synthesis of coronaridine (648) by aluminum hydride reduction of a bridged lactam, followed by dehydration on alumina. Additional examples of enamine formation by reduction of enamides (649) and thioenamides (650) were reported. 

As described in Section 1.7.1, the utility of the Wenker reaction is limited to substrates without labile functionalities because of the involvement of strong acid and then strong base. The Fanta group prepared a variety of aziridines by taking advantage of the Wenker reaction.For example, 6-aza-bicyclo[3.1.0]hexane (14) was produced from the ring-closure of ( )-rra s-2-aminocyclopentanol hydrochloride (13). In a similar fashion, sulfate ester 16 was prepared from A-methyl dl-trans- >-ssmnoA-hydroxytetrahydrofuran (15). Subsequent treatment of sulfate ester 16 with NaOH then delivered aziridine I . " Additional examples of Wenker aziridine synthesis may also be found in references 15-17. 

Additional examples of the reactivity of the 4-position in thiophenes with —I-j-M-substituent in the 3-position are provided by the bromination of 3-thiophenecarboxylic acid to 2,4,5-tribromothio-phenecarboxylic acid and the recent diacetylation of 2,5-dimethyl-thiophene by Goldfarb et who used the swamping catalyst... 

Comparison of the ortho and para indirect deactivation in 155 and 156 with that in 151 and 152 would reveal the relative effectiveness of the two effects and the influence of the ring-position. Additional examples of deactivation are ortho indirect in 2-chloro-6-methoxy-pyrazine ortho direct in 4-chloro-5-methoxypyrimidine para direct in 2-chloro-5-methoxypyrimidine ortho and para indirect in the... 

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