Alkyl nitrogen compounds

Other elements give rise to further characteristic functional groups. For example, alkyl nitrogen compounds are amines. The replacement of oxygen in alcohols by sulfur furnishes thiols. 

It has been tentatively suggested that one mechanism underlies the Willgerodt reaction and the Kindler modification of it. A labile intermediate is first formed which has a carbon—carbon bond in the side chain. The scheme is indicated below it postulates a series of steps involving the addition of ammonia or amine (R = H or alkyl), elimination of water, re addition and eUmination of ammonia or amine until the unsaturation appears at the end of the chain then an irreversible oxidation between sulphur and the nitrogen compound may occur to produce a thioamide. 

Although only ppm levels of nitrogen are found in the mid-distillates, both neutral and basic nitrogen compounds have been isolated and identified in fractions boiling below 345°C (12). Pyrroles and indoles account for about two-thirds of the nitrogen. The remaining nitrogen is found in the basic pyridine and quinoline compounds. Most of these compounds are alkylated. 

Azole iV-oxides, iV-imides and iV-ylides are formally betaines derived from iV-hydroxy-, iV-amino- and iV-alkyl-azolium compounds. Whereas iV-oxides (Section 4.02.3.12.6) are usually stable as such, in most cases theiV-imides (Section 4.02.3.12.5) andiV-ylides (Section 4.02.3.12.3) are found as salts which deprotonate readily only if the exocyclic nitrogen or carbon atom carries strongly electron-withdrawing groups. 

Phosphorus-nitrogen compounds containing alkylated amino groups can be cleaved by fluormatmg agents Phenyldifluorophosphine is formed from the reaction of A,MA, lV -tetramethylphenylphosphonous amide and benzoyl fluoride [79] (equation 17). 

An interesting intermediate 30 was proposed to result from the sequential addition of pyridine to tetrachlorocyclopropene (31). Compound 30 represents an alkyl nitrogen ylide with two 1-chloroalkyl pyridinium moieties in the same molecule. Pyridines with electron-withdrawing groups and heterocycles with an electron-deficient nitrogen, for example, pyridine-3-carbaldehyde or quinoline, react with 31 to yield the corresponding mono-substituted products 32a and 32b (83JOC2629) (Scheme 8). 

The rupture of the oxazirane ring at the ON-bond occurring with acid treatment of the alkyl-substituted compounds is probably the result of an electronic shift initiated by the protonated oxygen (arrows as in 21). In principle, a similar rearrangement of the electronic system should also be possible initiated from the nitrogen end (22), Indeed, decomposition products similar to those of the... 

The alkylation of heterocyclic nitrogen compounds with alkyllithium reagents is called Ziegler alkylation. Aryllithium reagents give arylation. The reaction occurs... 

Aldehydes, formates, primary, and secondary alcohols, amines, ethers, alkyl halides, compounds of the type Z—CH2—Z, and a few other compounds add to double bonds in the presence of free-radical initiators/ This is formally the addition of RH to a double bond, but the R is not just any carbon but one connected to an oxygen or a nitrogen, a halogen, or to two Z groups (defined as on p. 548). The addition of aldehydes is illustrated above. Formates and formamides " add similarly ... 

Nitrous acid or alkyl nitrites react with a number of nitrogen compounds to yield tetrazoles. For example, hydrazidines (87), which can be prepared in situ from the corresponding iminoesters, react with nitrous acid or its derivatives to give 1-substituted tetrazoles (88).150-152 This reaction (Eq. 17), is one of the most extensively used methods for the synthesis of... 

Quaternary ammonium salts are organically substituted nitrogen compounds in which the nitrogen atom is pentavalent. Four of the substituents are alkyl, aryl or heterocyclic radicals and the fifth is an anion (a cationic charge). This anion is mostly chloride. Therefore we call them benzalkonium chlorides. 

E. L. Shock (1990) provides a different interpretation of these results he criticizes that the redox state of the reaction mixture was not checked in the Miller/Bada experiments. Shock also states that simple thermodynamic calculations show that the Miller/Bada theory does not stand up. To use terms like instability and decomposition is not correct when chemical compounds (here amino acids) are present in aqueous solution under extreme conditions and are aiming at a metastable equilibrium. Shock considers that oxidized and metastable carbon and nitrogen compounds are of greater importance in hydrothermal systems than are reduced compounds. In the interior of the Earth, CO2 and N2 are in stable redox equilibrium with substances such as amino acids and carboxylic acids, while reduced compounds such as CH4 and NH3 are not. The explanation lies in the oxidation state of the lithosphere. Shock considers the two mineral systems FMQ and PPM discussed above as particularly important for the system seawater/basalt rock. The FMQ system acts as a buffer in the oceanic crust. At depths of around 1.3 km, the PPM system probably becomes active, i.e., N2 and CO2 are the dominant species in stable equilibrium conditions at temperatures above 548 K. When the temperature of hydrothermal solutions falls (below about 548 K), they probably pass through a stability field in which CH4 and NII3 predominate. If kinetic factors block the achievement of equilibrium, metastable compounds such as alkanes, carboxylic acids, alkyl benzenes and amino acids are formed between 423 and 293 K. 

Carbazole is a non-basic nitrogen compound, whose removal via hydrotreating is limited by its low reactivity. The removal of nitrogen by hydrotreatment involves a number of steps that take place on the catalyst surface. The weak interaction of neutral nitrogen compounds with catalysts precludes carbazole and its derivatives from being denitro-genated and makes them the most recalcitrant components in HDN of gas oils [308], In fact, it has been found that the nitrogen content of hydrotreated gas oil from Athabasca bitumen was composed primarily of alkyl carbazoles [309],... 

Several species of the genus Pseudomonas have been isolated that degrade carbazole and its alkyl derivatives and a variety of other microorganisms have been reported to mineralize non-basic nitrogen compounds, including species of Bacillus, Xanthomonas, Burkholderia, Comamonas, Beijerinckia, Mycobacterium, and Serratia [310],... 

A two phase process, in which the feedstock (e.g., petroleum) was mixed with water and an organic solvent to improve denitrogenation of aromatic nitrogen compounds [102], led to an improvement of the process. Additionally, a surfactant was used to increase the interfacial area. Carbazole and quinoline and their alkyl derivatives were used as primary compounds for demonstration. The biocatalyst is used in resting stage and is continuously fed to the system to keep the reaction rate at an acceptable level. It was observed that quinoline was hardly removed under the conditions at which carbazole was decomposed and assimilated. 

Similar to nitrogen compounds, electron-rich sulfur compounds, such as the sulfides, with the lone pair of electrons on the sulfur atom, are oxidized to sulfoxides and, further, to sulfones by the H202/titanosilicate sytem (218,232, 233). Table XXXI (232) illustrates typical conversions and product selectivities for various sulfides for the reactions catalyzed by TS-1. Bulky sulfides such as alkyl, phenyl sulfides are relatively unreactive because of their steric exclusion from the pores of TS-1. Diphenyl sulfide could not be oxidized at all. As the diffusivity and, hence, the conversion of the sulfide decreases, the further oxidation of the primary product (sulfoxide) becomes more competitive, leading to increased formation of the corresponding sulfone (Table XXXI) ... 

The OPLS parameters (charges and Lennard-Jones terms) were obtained primarily via Monte Carlo simulations with particular emphasis on reproducing the experimental densities and heats of vaporization of liquids. Those simulations were performed iteratively as part of the parametrization, so better agreement with experiment is obtained than in previous studies where the simulations were usually carried out after the parametrization. Once the OPLS parametrization was completed, further simulations were also performed in order to test the new set of parameters in the calculation of other thermodynamic and structural properties of the system, besides its density and its heat of vaporization. Parameters have now been generated, among others, for water, alkanes, alkenes, alcohols, amides, alkyl chlorides, amines, carboxylic esters and acids, various sulfur and nitrogen compounds, and nitriles. A protein force field has been established as well. 

Chloroanisole Polychlorobiphenyls Chlorodibenzo-p-dioxins and chlorodibenzofurans Basic nitrogen compounds Alkyl and aryl phosphates... 

Quaternary fluorinated alkyl ammonium compounds The fluorine-containing cationic surfactants of quat type with the general formula C F2 , 1-S02-NH-CH2-CH2-CH2-N (CH3)3 X (n = 8) (Fig. 2.12.1(d)) were examined by FIA—MS using APCI and ESI in the positive and negative modes. The APCI(- -/—) ionisation resulted in a dealkylation at the nitrogen with ions at m/z 585 or 583, respectively. The alkyl chain of this compound contained the moiety C8Fi7. The ions generated under APCI conditions were characterised as dealkylation products—m/z 585 [M — CH2]+ or m/z 583 [M — H— CH3] —as reported in the literature [35,37]. 

II. CORRELATIONS OF ENTHALPIES OF FORMATION OF ALKYL NITROGEN-CONTAINING COMPOUNDS... 

Indeed, the choice of a nitrogen compound to be used as carrier in such O-alkyl prodrugs is not restricted to benzamides. Other amides were examined, e.g., phthalimide, succinimide, and saccharin. Thus, the saccharin prodrug of estradiol (11.50, R = 17/J-estradiol) underwent rapid nonenzymatic hydrolysis in rat and human plasma [85]. Administration of the prodrug to rats led to an impressive fivefold increase in the oral bioavailability of estradiol, and it was approximately nine times more potent orally, based on the 50% effective dose. 

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