Nitrogen-containing quinolines

Employing Jefferey s ligandless conditions, Larock and Babu (87TL5291) synthesized quinolines and other nitrogen-containing heterocycles via the intramolcular Heck reaction strategy as exemplified by reaction 144 145. This reaction is similar to the Mori-Ban indole... 

Fragment ions Nitrogen-containing heterocyclics, such as pyridines, quinolines, and acridines, lose HCN and/or H2CN from their molecular ions. 

Reaction of 3-benzamido-2,5-dioxo-5,6,7,8-tetrahydro-(2ff)-l-benzopyrans 58 with nitrogen-containing nucleophiles (amines and hydrazines) provides the corresponding quinolin-2-(l//)-ones 59 <96H(43)809>. 

AO is also effective in metabolizing a wide range of nitrogen-containing heterocycles such as purines, pyrimidines, pteridines, quinolines, and diazanaphthalenes (95). For example, phthalazine is rapidly converted to 1-phthalazinone by AO and the prodrug, 5-ethynyl-2-(l//)-pyrimidone, is oxidized to the dihydropyrimidine dehydrogenase mechanism-based inhibitor, 5-ethynyluracil, by AO (Fig. 4.40) (96). 

The Balz-Schiemann synthesis can be applied not only to substituted anilines but also to aminobiphcnyls1,131 or amino-substituted fused polyaromatic compounds, such as naphthalene,1114,119,129 anthracene,136 phenanthrene,1135 acenaphthene,133 fluorene,1,131,134 benzanthracene,130 136 pyrene,136 chrysene,136 fluoranthene,131 fluorenone,1,131 anthra-quinone,1,137,139,140 benzanthrone,1,117,118 phenanthraquinone,138 or xanthone.132 Fluorinated pyridines,1,141"146 methylpyridincs,126,147 149 pyridinecarboxylic acids,150 quinolines,1,151 isoquinolines,152 quinazolone,1 thiazoles,153,154 isothiazoles,156 benzothiazoles,157 thiadiazoles,155 and thiophenes154 can also be obtained from the corresponding aminated heterocycles. Modified Balz-Schiemann methods are recommended for amino nitrogen-containing heterocycles, the diazonium salts of which are rather water-soluble and unstable (a violent explosion was reported for pyridine-3-diazonium tetrafluoroborate).159 These new techniques have also been specially adapted for pyrazol-, imidazol-, or triazolamines which fail to react under classical conditions.158... 

This reaction will work with other nitrogen containing heterocycles such as quinoline. 

A variety of heterocyclic systems have been used for forming merocyanines. The more usual nitrogen-containing heterocycles involved include benzimidazole, quinoline, ben-zothiazole, benzoselenazole, thiazole, thiazoline and indolenine. Among the more useful carbonyl-containing heterocycles are derivatives of 2-pyrazolin-5-one, 2-thiobarbituric acid, rhodanine and hydantoin. 

Alkaloids are often classified according to the nature of the nitrogen-containing structure, e.g. pyrrolidine, piperidine, quinoline, isoquinoline, indole, etc, though the structural complexity of... 

After studying various nitrogen-containing compounds, we found that the zinc alkoxide of 2-methyl-l-(3-quinolyl)propan-l-ol 5 (Fig. 1) catalyzes the enantioselective formation of itself with the same configuration in the reaction between quinoline-3-carbaldehyde and z-P Zn to produce the product 5 in high ee (up to 94% ee) [58]. In addition, the 5-carbamoyl-3-pyridyl alkanol 6 (Fig. 1) can act as an efficient autocatalyst to catalyze its own production in a highly enantioselective manner (up to 86% ee) [59]. 

Polycyclic aromatic nitrogen compounds, such as quinoline, indole, acridine, and carbazole, are the main nitrogen-containing compounds in oil fractions, and monocyclic pyridine and pyrrole as well as anilines are present in coal tar (Scheme 11). Saturated cyclic amines are found as products of ring hydrogenation of the compounds shown in Scheme 11 after HDN. Aliphatic amines are rarely found in fuels and only in low concentrations after HDN since their nitrogen atoms are easily removed. 

A two-site model was used as well by Shih et al. (102) for the HDN of quinoline. They assumed not only pseudo-first-order kinetics but also that all nitrogen-containing species, including ammonia, have the same adsorption equilibrium constant this is clearly not the case (77). 

The compounds best known for their bitter taste belong to the alkaloids and glycosides. Alkaloids are basic nitrogen-containing organic compounds that are derived from pyridine, pyrrolidine, quinoline, isoquinoline, or purine. Quinine is often used as a standard for testing bitterness (Figure 7-13). 

---