Basic nitrogen functionality

Coal-derived asphaltene contains more hydroxyl and pyrrolic groups in addition to ether-oxygen or basic nitrogen functions. 

Basic nitrogen species present on the surface of activated carbons or carbon fibers, like in the case of H2S, were found to enhance the sulfur dioxide uptake. Polyacrylonitrile (PAN)-based activated carbon fibers are examples of good adsorbents for SO2 removal [82, 92]. Although role of nitrogen present in the carbon matrix was not emphasized by Lee and coworkers [93] in their studies of SO2 adsorption on PAN-based activated carbon fibers, [93] Kawabuchi and coworkers noticed a significant increase in the sorption capacity when activated carbon fibers were modified with pyridine and basic nitrogen functionalities were introduced to the surface [93]. Pyridine provided basic functionality, which increased catalytic removal of SO,. . 

From other information concerning the molecular structure, such as isotope peak calculations, exact mass measurements, or spectral or chani-cal evidence, the presence or absence of nitrogen may be known. A compound known to be a steroid, for example, must have an even molecular weight. On the other hand, a substance that becomes water soluble under acidic conditions must contain at least one basic nitrogen function in this case, the molecular weight may be odd or even, depending on the number of nitrogen atoms actually present. 

As shovm above, the attachment of the aromatic ring to the carbon chain bearing the basic nitrogen may be accomplished through an ester or an amide configured in either direction. A simple ether linkage fulfills this function in yet another compound that exhibits local anesthetic activity. Thus, alkylation of the mono potassium salt of hydroquinone with butyl bromide affords the ether (77) alkylation of this with w-C3-chloropropyl)morpholine affords pramoxine (78)... 

A change in the pK of the molecule by elimination of the acidic enol function and inclusion of basic nitrogen leads to a marked change in biologic activity. That agent, chromonar (13) shows activity as a coronary vasodilator. Alkylation of ethyl acetoacetate with 2-chlorotriethylamine affords the substituted ketoester (10). Condensation with resorcinol in the presence of sulfuric acid affords directly the substituted coumarin (11). 

Compounds containing a basic nitrogen, such as 2-chloroaniline. may function as their own hydrogen-halide acceptor (4). The rate of reduction is greatly retarded by added hydrogen chloride. 

Results and data gathered on mass spectroscopy of various indole alkaloids have been summarized by Hesse (320). The derivation of the characteristic fragments of indolo[2,3-a]quinolizidines has been interpreted by Gribble and Nelson (321), who investigated C-3, C-5, C-6, C-20, and C-21 deuterated derivatives of octahydroindolo[2,3-a]quinolizine (1). Kametani et al. have observed and proved, with labeled compounds, a methyl transfer from the ester function of reserpine derivatives to the basic nitrogen atom during mass-spectroscopic measurement (322). 

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