Functional groups amino

The amino functional group is not commonly encountered in steroid synthesis except perhaps in steroidal alkaloids. However, certain elimination reactions have been shown to have theoretical and limited preparative importance, largely due to the efforts of McKenna and co-workers. The Hofmann rule for 2 elimination predicts that alkaline elimination of quaternary ammonium salts will occur towards the carbon carrying the most hydrogen atoms cf. the converse Saytzeff orientation, above). In cyclohexyl systems, the requirement for diaxial elimination appears to be important, as in other 2 eliminations, and the Hofmann rule frequently is not obeyed [e.g., (116) (117)]. 

Figure 33-2. Tautomerism of the oxo and amino functional groups of purines and pyrimidines.

C17-0106. Putrescine, a substance with a vile odor, has two basic amino functional groups, as shown in the line... 

It has been demonstrated by Hauser and coworkers that 8-amino-ethyl ferrocene ( 3) undergoes reactions typical of the amino functional group. 

In 3, the amino functional group is two methylene units removed from the ferrocene nucleus. It appears from the instantaneous and quantitative formation of h from 3 that this feature minimizes steric effects and also enables 3 to undergo the Schotten-Baumann reaction readily without the classical a-metallocenylcarbenium ion effects providing any constraints. The IR spectrum of showed the characteristic N-H stretch at 3320 cm" (s), the amide 1 (carbonyl) stretch at 1625 an - -(s), the amide II (N—H) stretch at 1540 cm (s), and the amide III band at 1310 cm 1(m). In addition, characteristic absorptions of the ferrocenyl group were evident at 1100 and 1000 cm l (indicating an unsubstituted cyclopentadienyl ring) and at 800 cm"l. 

It is well established that primary amino-functional groups, particularly aliphatic ones, react instantaneously with isocyanates to form ureas at ambient temperature. Indeed this was observed when 6-aminoethylferrocene (3) and freshly distilled phenylisocyanate were shaken vigorously. A yellow precipitate separated out immediately. Elemental analysis and an IR spectrum of the product indicate this compound to have the structure 6. ... 

Not all drugs contain functional groups that lend themselves readily to prodrug derivatization. A case in point is the carbonic anhydrase inhibitors such as acetazolamide, ethoxzolamide, and methazolamide. Although the amino functional group of their sulfonamide moiety can be methylated, the resulting analogs... 

Acetyltransferases catalyze the acetylation of amino, hydroxyl, and thiol functional groups. Acetylation of hydroxy and thiol groups is comparatively rare and of much less importance in alkaloid metabolism than reactions with amino functional groups. The types of amines that are acetylated include arylamines (the major route of metabolism in many species), aliphatic amines, hydrazines, sulfonamides, and the a-amino group of cysteine conjugates. The purification, physical properties, and specificity of the N-acetyltransfereases have been reviewed (116-118). 

T The compound has several types of quaternary ammonium and amino functional group. 

This triiodinated synthon has an amino functional group (A) that is potentially reactive with the chloride functional groups of the acid (B). The amino functional group is protected in the form of a phthalimido group. 

Some functional groups can be introduced into polymers by conversion of one functional group to another. For example, pendant or end-group halogens can be displaced by nucleophilic substitution to yield hydroxyl or amino functional groups. 

Potentiometric titration studies were used to obtain values for the two ionization constants of dorzolamide hydrochloride. The first of these yielded pK, = 6.35, corresponding to the secondary amino functional group. The second ionization corresponded to sulfonamido group, for which pK 2 ... 

From numerous studies, it has now been established that the amino functional groups (—NH2) is essential for the activity. In addition, the following structural features have to be present in sulpha drugs for the optimum antibacterial activity. 

Gas chromatographic separation of -agonist residues is generally complicated by the necessity of derivatization of their polar hydroxyl and amino functional groups. Silyl derivatives are preferentially prepared by treating sample extracts with N,0-bis(trimethylsilyl)trifluoroacetamide (470,471,473,475,483, 487), N-metliyl-N-(trimethylsilyl)trifluoroacetamide (482) or N-methyl-N-(tert-butyldimethylsilyl)trifluoroacetamide (473, 487). Pentafluoropropionic anhydride (481), phosgene (484), trimethylboroxine (480), methyl- and butylboronic acid (489), or a combination of N,O bis(trimethylsilyl)trifluoroacetamide with... 

POMs can he immobilized onto anion-exchange resins and surface-modified metal oxides with quaternary ammonium cation- or amino-functional groups via anion-exchange. Jacobs and coworkers tethered Venturello s catalyst [P04(W0(02)2)4]3-on a commercially available nitrate-form resin with alkylammonium cations and have carried out the epoxidation of allylic alcohols and terpenes with this supported catalyst [166, 167]. The regio- and diastereoselectivity of the parent homogeneous catalysts were preserved in the supported catalyst. For bulky alkenes, the reactivity of the POM catalyst was superior to that of Ti- 3 zeolite with a large pore size. The catalytic activity of the recycled catalyst was maintained completely after several cycles. 

It is shown [100] that polyhalide derivatives of iron and manganese porphyrin catalysts applied on Si02 and polymeric matrices via their amino functional group were successfully synthesized. 

Release of peptides with ammonia might work only on homemade membranes. Commercially available membranes with amino functional groups often have other than ester bonds between the spacer and cellulose. For such membranes the use of additional linkers might be necessary (e.g., thioester (66), HMB linker (67), Rink linker (68)). 

The epoxy dispersion can be reacted into the latex polymer either by reacting the epoxy with a functionalized latex (carboxyl or amino functional groups) or by use of an epoxy with an epoxy coreactant or curing agent. In the latter case, the epoxy will react with the coreactant and form a network within the latex polymer network. 

Derivatization of non-volatile polar or thermally sensitive compounds to enhance their volatility and stability prior to chromatography is a well-established technique. Compounds containing hydroxyl, carboxyl and amino functional groups can be readily reacted with appropriate reagents to convert these polar groups into much less polar methyl, trimethylsilyl or trifliioroacetyl derivatives of greater volatility. Fatty acids. Carbohydrates. 

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