Secondary containment

Desipramine [50-47-5] (35) and nortriptyline [72-69-5] (36) are demethylated derivatives and principal metaboHtes of (32) and (33), respectively. Both compounds possess less sedative and stronger psychomotor effects than the tertiary amine counterparts, probably because tricycHcs containing secondary amine groups generally show greater selectivity for inhibiting the reuptake of norepinephrine compared with the reuptake of serotonin. Protriptyline [438-60-8] (37), a stmctural isomer of nortriptyline, is another important secondary amine that displays a similar clinical profile. 

The Sierra product line contains secondary and minor elements. Sierrablen products, ie, blends of Osmocote with uncoated nutrients for quicker... 

It has been found " that those derivatives of 3-aminopropan-l-ol react most readily which contain secondary amino and hydroxyl groups as in the original formation of (1). The reaction can be catalyzed by alkaline reagents, e.g., small amounts of potassium hydroxide. 

These differences have been attributed to various factors caused by the introduction of new structural features. Thus isopentane has a tertiary carbon whose C—H bond does not have exactly the same amount of s character as the C—H bond in pentane, which for that matter contains secondary carbons not possessed by methane. It is known that D values, which can be measured, are not the same for primary, secondary, and tertiary C—H bonds (see Table 5.3). There is also the steric factor. Hence, it is certainly not correct to use the value of 99.5 kcal mol (416 kJ mol ) from methane as the E value for all C—H bonds. Several empirical equations have been devised that account for these factors the total energy can be computed if the proper set of parameters (one for each structural feature) is inserted. Of course these parameters are originally calculated from the known total energies of some molecules that contain the structural feature. 

Sulfonic esters are most frequently prepared by treatment of the corresponding halides with alcohols in the presence of a base. The method is much used for the conversion of alcohols to tosylates, brosylates, and similar sulfonic esters. Both R and R may be alkyl or aryl. The base is often pyridine, which functions as a nucleophilic catalyst, as in the similar alcoholysis of carboxylic acyl halides (10-21). Primary alcohols react the most rapidly, and it is often possible to sulfonate selectively a primary OH group in a molecule that also contains secondary or tertiary OH groups. The reaction with sulfonamides has been much less frequently used and is limited to N,N-disubstituted sulfonamides that is, R" may not be hydrogen. However, within these limits it is a useful reaction. The nucleophile in this case is actually R 0 . However, R" may be hydrogen (as well as alkyl) if the nucleophile is a phenol, so that the product is RS020Ar. Acidic catalysts are used in this case. Sulfonic acids have been converted directly to sulfonates by treatment with triethyl or trimethyl orthoformate HC(OR)3, without catalyst or solvent and with a trialkyl phosphite P(OR)3. ... 

NMR line broadening is a suitable kinetic method for determining activation parameters for Co—C bond homolysis, and gave A//- values in the range 18-22.5 keal mol for a selection of Co(Por)R complexes containing secondary or tertiary alkyl groups.Bond dissociation enthalpies and entropies for several... 

Physical separation of granulometric fractions by sedimentation and ultracentrifugation could also help in constraining weathering rates at local scale. The fine fractions are useful when they exclusively contain secondary minerals, that is, when they are not polluted by... 

Figure 9.3 Chemical stmctures for the phosphorous-containing secondary antioxidants Naugard 524 (A) tris(nonylphenyl)phos-phite (B) and Irgafos P-EPQ (C). After Brandolini et al. [49]. Reprinted from Spectroscopy, 7(3), AJ. Brandolini et al., 34-39, Copyright (1992), with permission from IOS Press...

The general metabolism of sulfur, extensively described in many texts of biological sciences, is not considered in this article some topics (e.g. metallo-enzymes) are discussed elsewhere in this volume (Chapter 11.2). Our focus is on sulfur-containing secondary metabolites in microorganisms and plants. In view of the vast literature, we can only provide an eclectic account citing recent work where possible. 

Overview of Structural Types for Sulfur-Containing Secondary Metabolites... 

Plants of the genus Allium, e.g. garlic Allium sativum), leek Allium amp-eloprasum), and onion Allium cepa), produce a bewildering variety of sulfur compounds. Selenium analogs for some of these have also been found (Section 11.1.3.6). Much work has focused on garlic (contains more than 100 such materials) and onion.56,66,67 Key compounds for formation of the Allium sulfur-containing secondary metabolites are sulfoxides of cysteine derivatives,... 

When the alkyl substituent contains secondary C-H bonds, both ring and side chain oxidation at the secondary C-H bond occur. Thus, ethylbenzene gives... 

Correlations between surface species and emitted secondary ions are based on characterization of the surface adlayer by adsorption and thermal desorption measurements. It is shown that the secondary ion ratios RuC+/Ru+ and R CTVRuJ can be quantitatively related to the amount of nondesorbable surface carbon formed by the dissociative adsorption of ethylene. In addition, emitted hydrocarbon-containing secondary ions can be directly related to hydrocarbon species on the surface, thus allowing a relatively detailed analysis of the hydrocarbon species present. The latter results are consistent with ejection mechanisms involving intact emission and simple fragmentation of parent hydrocarbon species. 

In this paper we have shown that a direct quantitative relationship can be established between the RuC+/Ru+ and Ru2C+/Ru2 ion ratios in SIMS and the surface carbon formed by the ethylene/ Ru(001) interaction at 323 K. We have also shown that a direct relationship can be established between emitted hydrocarbon-containing secondary ions in SIMS and the small amounts of hydrocarbon species formed by the ethylene/Ru(001) interaction. The results are furthermore consistent with an ejection mechanism involving intact emission and simple fragmentation of the parent hydrocarbon species. Finally, the results of this study provide a relatively detailed description of the behavior of the rather small amounts of hydrocarbon species produced by the ethylene/ Ru(001) interaction, thus illustrating the potential of SIMS for investigating surface reactions. 

Pore size distribution data obtained from adsorption isotherms and from mercury porosimetric measurements show that in addition to the micropores characteristic of the parent zeolite, the DAY zeolites contain secondary pores with radii of 1.5nm (supermicropores) and lOnm (mesopores) (36,47). The secondary pores in USY-B have a radius of 5nm. It was also shown that the micropore volume of DAY amounts to about 75 percent of that of NaY (36). Due to dealumination and the formation of secondary pores, the total pore volume of DAY is considerably larger than that of NaY zeolite (0.56 vs. 0.29 cc/g). 

Di (l carbethoxyethyl) phosphorofluoridate (XV) was readily produced by the action of sodium fluoride on the corresponding phosphorochloridate obtained from di-(l -carbethoxyethyl) hydrogen phosphite, which in turn was obtained by the action of phosphorus trichloride on ethyl lactate. Although (XV) contained secondary groupings, it was found to be relatively nontoxic and to produce only slight myosis in the pupils of the eyes of rabbits and guinea-pigs. 

Tris(2,2 -bipyridine)ruthenium(UI) complex ions (44) produce a chemiluminescence in the presence of amino acids in a FTA system. Amino acids containing secondary amino groups have the strongest response LOD 20 pmol for proline to 50 nmol for... 

Besides the effect of solvent polarity, the C=C rotation in many push-pull ethylenes is sensitive to acid catalysis (143). This is probably explained by protonation of the acceptor groups, for example, the oxygen atoms in C=0 groups (16), which increases their acceptor capacity. Small amounts of acids in halogenated solvents, or acidic impurities, may have drastic effects on the barriers, and it is advisable to add a small quantity of a base such as 2,4-lutidine to obtain reliable rate constants (81). Basic catalysis is also possible, but it has only been observed in compounds containing secondary amino groups (38). 

Purifications of the methanolic extract of adults and larvae of the New Guinean species Epilachna signatipennis led to the isolation and structure determination of three nitrogen-containing secondary metabolites choline (24), L-hypaphorine (25), and signatipennine (26) (Fig. 5). From a biosynthetic... 

Fig. 5 Nitrogen-containing secondary metabolites found in Epilachna signatipennis...

Perhaps most conspicuous by their absence from the list (cf. Table VIII) are the alkaloids. These substances, generally defined as nitrogen-containing secondary metabolites, are common plant products and usually have distinct physiological activities. Nevertheless, to date no reports seem to have appeared concerning the presence (or absence) of alkaloids as Gossypium metabolites. 

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