Nitrogen-containing compounds cyclic

Nitrogen compounds are also effective as nucleophiles in the anodic oxidation of silyl-substituted ethers. The electrochemical oxidation in the presence of a carbamate or a sulfonamide in dry THF or dichloromethane results in the selective cleavage of the C-Si bond and the introduction of the nitrogen nucleophile at the carbon (Scheme 21) [55]. Since a-methoxycarbamates are useful intermediates in the synthesis of nitrogen-containing compounds [44], this reaction provides useful access to such compounds. Cyclic silyl-substkuted ethers such as 2-silyltetrahydrofurans are also effective for the introduction of nitrogen nucleophiles. The anodic oxidation in the presence of a carbamate or a... 

The only cationic surfactant (Fig. 23) found in any quantity in the environment is ditallow dimethylammonium chloride (DTDMAC), which is mainly the quaternary ammonium salt distearyldimethylammonium chloride (DSDMAC). The organic chemistry and characterization of cationic surfactants has been reported and reviewed [330 - 332 ]. The different types of cationic surfactants are fatty acid amides [333], amidoamine [334], imidazoline [335], petroleum feed stock derived surfactants [336], nitrile-derived surfactants [337], aromatic and cyclic surfactants [338], non-nitrogen containing compounds [339], polymeric cationic surfactants [340], and amine oxides [341]. 

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. 

Nucleoside (Section 27.1) A component of a nucleic acid containing a sugar, either ribose or 2 -deoxyribose, and a base, a cyclic nitrogen-containing compound. 

The structures of the most important bases are drawn on p. 36. They are all cyclic, nitrogen-containing compounds. The hydrogen atoms with the circles around them indicate the specific nitrogen in each base that is bonded to a sugar molecule. 

Many different types of nitrogen-containing compounds have been shown in oil shale. Poulson and co-workers reported that pyridines and pyrroles were major types of nitrogen compounds in shale oil. Cyclic amides and anilides were proposed as possible additional types of nitrogen compounds in shale oil. Van Meter and co-workers found benzonitriles in shale oil naphtha. Brown and co-workers identified alkylpyr-idines, cycloalkanopyridines, alkylanilines, quinolines, tetrahydroquinolines, and tetrahydroisoquinolines in... 

The hydrogenation of cyclic nitrogen containing compounds proceeds very slowly and with a very low conversion. This reaction proceeds in four steps shown in the reaction equation (6.49). 

Reactions of Nitrogen-containing Compounds. - Irradiation of cyclic nitrocompounds in base (i.e. as the nitronate anion) leads to ring-expansion [e.g. 

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