Containing two nitrogens

In these three cases, ligands containing two nitrogen atoms appear to produce results similar or often superior to most of the other type of ligands. Although a review was published on this area five years ago, the recent results are of considerable practical interest and an updated review seems perfectly justified. 

Most of us have had to endure the discomfort of dentai work, be it repairing cavities or more eiaborate orai surgery. Dentists reduce the discomfort immenseiy by the use of a iocai painkiiier. Novocain, to biock the nerves in the mouth. Novocain is a weak base containing two nitrogen atoms. A reiated anaigesic, iidocaine (aiso known as Xyiocaine), is sufficientiy strong that appiying it to the skin causes the nerves in the immediate area to shut down temporariiy. 

Urea, which contains two nitrogens, is synthesized in the liver from aspartate and carbamoyl phosphate, which in turn is produced from ammonium ion and carbon dioxide by mitochondrial carbamoyl phosphate synthetase. The urea cycle and the carbamoyl phosphate synthetase reaction are shown in Figure 1-17-2. 

Diazocines are eight-membered heterocycles containing two nitrogen atoms. The A-nitro and A-nitroso derivatives of 1,5-diazocines are energetic materials with potential for use in high-energy propellants. 

Aromatic heterocycles containing two nitrogen atoms are best reduced by catalytic hydrogenation. Other reduction methods may cleave some of the rings. Even catalytic hydrogenation causes occasional hydrogenolysis. 

A series of tranquilizers, drugs that relieve anxiety and nervous tension without impairing consciousness, have a benzene ring fused to a seven-membered ring containing two nitrogens. As a group they are called benzodiazepines. The two most successful are diazepam (Valium ) and chlordiazepoxide (Librium ) introduced in 1964 and 1960, respectively. Flurazepam (Dalmane ), first used in 1970, is a hypnotic. 

An example of the use of GC with nitrogen selective detection is in the quantification of bupivacaine in plasma. Bupivacaine contains two nitrogen atoms in its structure which makes it a good candidate for this type of analysis. The limits of detection which can be achieved with a nitrogen selective detector for this compound are much better than methods based on flame ionisation detection, which are much less selective. 

The basic chemical structure of the benzodiazepines consists of a benzene ring coupled to a seven-member heterocyclic structure containing two nitrogens (di-azepine) at positions 1 and 4 (Fig. 30.1). Of the 2,000 benzodiazepines that have been synthesized, approximately 15 clinically useful compounds are on the market in the United States (Table 30.1). 

Azole antifungal drugs are synthetic compounds with broad-spectrum fungistatic activity. Azoles can be divided into two groups the older imidazole agents, in which the hve-member azole nucleus contains two nitrogens, and the newer triazole compounds, fluconazole and itraconazole, in which the azole nucleus contains three nitrogens. 

Pyrazole and Imidazole. These are five-membered ring heterocycles containing two nitrogens, one basic and one neutral. Two common forms are pyrazole (1,2-diazole) and imidazole (1,3-diazole) both are prone to aromatic hydroxylation. 

A. Dinitrogen monoxide, sulfur hexafluoride, and dichlorine octoxide. Notice that none of these compounds contain any metals, which means that they re most certainly molecular compounds. The first compound contains two nitrogen atoms and one oxygen atom, so it s called dinitrogen monoxide. The second compound contains one sulfur and six fluorines. Because sulfur is the first named element, you don t need to include a mono- prefix. You simply name the compound sulfur hexafluoride (rather than monosulfur hexafluoride ). Using the same methods, the third compound is named dichlorine octoxide. 

The various topics discussed in this book have up to this point been arranged as far as possible on the basis of chemical structure compounds that contain one oxygen and one nitrogen atom have, for example, as a general rule preceded those that contain two nitrogen atoms. The fact that virtually all of the entities that follow show CNS activity combined with the circumstance that phenothiazines comprise a large part of this section require a departure from that approach. The serendipitous discovery of the antipsychotic activity of the phenothiazines in the early 1950s virtually opened the modern era of medicinal chemistry. These will thus be discussed at the outset to preserve historical perspective. 

Pyrimidine is a six-membered aromatic heterocyclic compound that contains two nitrogen atoms, separated by a carbon atom, in the ring. Nucleic acids, DNA and RNA, contain substituted purines and pyrimidines. Cytosine, uracil, thymine and alloxan are just a few of the biologically significant modified pyrimidine compounds, the first three being the components of the nucleic acids. 

Only one kind of six-membered ring system containing two nitrogens and one sulfur has been prepared from thiourea-type starting materials, namely 1,3,5-thiadiazines. The first report of this sort of preparation is that of Fromm and Weller,65 who in 1908 found that the thiourea... 

Containing one nitrogen, one oxygen—other compounds Benzyl isocyanate, 30 N-Methyl-N,0-bis(trimethylsilyl)-hydroxylamine, 187 Norephedrine, 200 Potassium f-butoxide, 252 Vinyltrimethylsilane, 343 Containing one nitrogen, one sulfur N-Methyl-o-aminothiophenol, 184 Containing two nitrogens Pivaldehyde, 249... 

Containing two nitrogens, one oxygen N-Methyl-N,0-bis(trimethylsilyl)-hydroxylamine, 187 Containing one oxygen—tetrahydro-furans... 

Containing one nitrogen, one oxygen Dichlorotris(triphenylphosphine)-ruthenium(II), 107 Potassium t-butoxide, 252 Containing two nitrogens Dichlorotris(triphenylphosphine)-ruthenium(II), 107 Trimethylamine N-oxide, 325... 

The selected examples of six-membered heterocyclic rings containing two nitrogen atoms are based on the pyrimidine [(73), 1,3-diazabenzene], pyrazine [(74), 1,4-diazabenzene] and quinoxaline [(75), benzopyrazine] systems. 

It is interesting to note that the anthracene-oil-base fraction contains heterocyclic compound types containing two nitrogens (33). This appears to be the first report of numerous SjH2N+ZN2 comPounc s i-n coal liquids. Minor amounts of dinitrogen compounds have been previously observed in these materials (34). 

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