Nitrogen containing aromatics

Figure 15.8 Pyridine and pyrimidine are nitrogen-containing aromatic heterocycles with tt electron arrangements much like that of benzene. Both have a lone pair of electrons on nitrogen in an sp2 orbital in the plane of the ring.

D. S. Treybig and R. G. Martinez. Compositions prepared from hydrocarbyl substituted nitrogen-containing aromatic heterocyclic compounds, an aldehyde and/or ketone and an amine. Patent US 4871848, 1989. 

Polarography of nitrogen containing aromatic compounds, values of the halfwave potential for the first reduction wave in dimethylformamide, tetraethyl-... 

MFor reviews of substitution on pyridines and other six-membered nitrogen-containing aromatic rings, sec Comins ... 

Figure 9. H3 antagonists derived from histamine-like scaffolds and substituted nitrogen containing aromatic heterocycles.

Four crystalline forms of the tricyclic nitrogen-containing aromatic molecule acridine (38) have been characterized (Lowde et al., 1953 Phillips, 1954). Form I is an orthorhombic hydrate, forms II and III are monoclinic, and form IV is orthorhombic. 

Greco [40] determined optimal extraction conditions for the recovery of nitrogen-containing aromatic compounds from soil. 

Schultz, T.W., Moulton, B.A. (1985) Structure-activity relationships for nitrogen-containing aromatic molecules. Environ. Toxicol. Chem. 4, 353-359. 

Because of the lack of the back-biting capability of the rigid aromatic diynes, their homopolycyclotrimerizations are not as easy to control as those of their congeners of flexible aliphatic diynes. Nevertheless, high molecular weight hb-PAs could be obtained in quantitative yields from the homopolycyclotrimerizations of nitrogen-containing aromatic diyne (59-65) catalyzed by... 

Itoh N, Izumi Y, Yamada H (1987) Haloperoxidase-catalyzed halogenation of nitrogen-containing aromatic heterocycles represented by nucleic bases. Biochemistry 26 282-289... 

The third system, the RT molten salt (class 3), is always a combination of organic salts R+X and aluminum halide A1X3 (R+ is usually a nitrogen-containing aromatic compound such as pyridinium, imidazolium, etc.). The properties of the ionic liquid are determined by the mole ratio of these components (l/m) according to the following reactions [455] ... 

N0TE Nitrogen containing aromatic compounds must be saturated before the nitrogen can be removed. 

A great number of publications deal with the reaction of nitration [7-20], At the same time, volumes literature on nitro heterocycles has not been systematized until the present time. Direct nitration of some five-membered heterocycles such as pyrroles, furans, thiophenes, pyrazoles, imidazoles, and thiazoles has been discussed by Katritzky [21, 22], Some synthetic routes to nitrated six-membered nitrogen-containing aromatic heterocycles [23], as well as the nitration of oxo-pyrimidines and -imidazoles [24], and quantum-chemical studies of the nitration of benzazoles [25] have been reported. 

The question about which of the imine or enamine forms dominates in the gas phase when both tautomers can equilibrate has been examined in a series of articles dealing with more complex nitrogen-containing aromatic compounds21-25. 

Some other capsules have been described in which both complimentary functions, carboxylic acids and nitrogen-containing aromatic rings, are respectively attached to the rims of two bowl-shaped molecules. Reinhoudt has prepared selfassembling, multi-hydrogen bonding molecular capsules in which a calix[4]arene substituted with four carboxylic functions at the upper rim interacts with a complimentary calix[4]arene with four pyridines attached to the lower rim. These capsules have been identified by H-NiMR, IR and VPO measurements but encapsulation properties have not been reported [106]. 

Experimental Zero-Field Splittings of Some Nitrogen-Containing Aromatic Compounds in Their Phosphorescent Triplet State3... 

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