Ammonia and related compounds

(a) Probable form of the potential energy curve for NH3. (b) The two possible configurations for the molecule NH3 or Naic. 

The structure of the molecule of hexamethylenetetramine, N4(CH2)e. N atoms are shaded and H atoms omitted. This molecule, based on a tetrahedral group of N atoms, should be compared with those of Be40(CH3C00)6, P4O6, and P4O10, Figs. 11.1 and 19.7. 

Three pyramidal bonds are formed by N in hexamethylenetetramine, N4(CH2)fi (Fig. 18.2), which has been studied many times, in the crystalline state by X-ray and neutron diffraction and in the vapour by electron diffraction. In the molecule in the crystal C-N, 1 476 A, C-H, 1-088 A, NCN, 113-6°, and CNC, 107-2° 

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Atoms, ions and particles that have a deficiency of electrons are called electrophiles, and will seek out areas of high electron density, i.e. the 8 of the O of the CO bond. Such reagents are quite numerous in chemistry and are very useful. The ones particularly useful for carbonyl compounds include the negatively polarised parts of H-CN (hydrogen cyanide) H-NH2 (ammonia and related compounds) and Na HSO (sodium hydrogensulfite) (Figure 7.2.5). 

Nitrogen oxides Sulphur compounds Carbon dioxide and monoxide Ammonia and related compounds... 

Ammonia and Related Compounds The Haber-Bosch process for the synthesis of ammonia involves the reaction below ... 

Pyrans and related compounds react with ammonia to give pyridines. A commercially useful example is the reaction of dehydroacetic acid (derived from diketene) with ammonia to give 2,6-dimethyl-4-pyridinone [7516-31 -6] via 2,6-dimethyl-4-pyridinone-3-carboxyhc acid [52403-25-5]. Chlorination of the pyridone gives clopidol [2971-90-6] (56), a coccidiostat (72,73). 

Aminoanthraquinone and Related Compounds. l-Amiuoanthraquiuone [82-45-1] (17) is the most important iatermediate for manufacturiag acid, reactive, disperse, and vat dyes. It has been manufactured from anthraquiaone-l-sulfonic acid [82-49-5] (16) by ammonolysis of the sulfo group with aqueous ammonia ia the presence of an oxidising agent such as nitroben2ene-3-sulfonic acid. 

Diaminoanthraquinone and Related Compounds. Leuco-l,4-diaminoanthraquinone [81-63-0] (leucamine) (32) is an important precursor for 1,4 diaminoanthraquinone [128-95-0] (33) and is prepared by heating 1,4-dihydroxyanthraquinone (29) with sodium dithionite in aqueous ammonia under pressure. 

The original commercial source of E was extraction from bovine adrenal glands (5). This was replaced by a synthetic route for E and NE (Eig. 1) similar to the original pubHshed route of synthesis (6). Eriedel-Crafts acylation of catechol [120-80-9] with chloroacetyl chloride yields chloroacetocatechol [99-40-1]. Displacement of the chlorine by methylamine yields the methylamine derivative, adrenalone [99-45-6] which on catalytic reduction yields (+)-epinephrine [329-65-7]. Substitution of ammonia for methylamine in the sequence yields the amino derivative noradrenalone [499-61-6] which on reduction yields (+)-norepinephrine [138-65-8]. The racemic compounds were resolved with (+)-tartaric acid to give the physiologically active (—)-enantiomers. The commercial synthesis of E and related compounds has been reviewed (27). The synthetic route for L-3,4-dihydroxyphenylalanine [59-92-7] (l-DOPA) has been described (28). 

Isothiazole itself is best prepared by the reaction between propynal, ammonia and sodium thiosulfate (see Section 4.17.9.3). A wide range of substituted mononuclear isothiazoles can be obtained by oxidative cyclization of y-iminothiols and related compounds (see Section 4.17.9.1.1). Substituents at the 3-position need to be in place before cyclization, but 4-substituents are readily introduced by electrophilic reagents (see Section 4.17.6.3), and 5-substituents via lithiation (see Section 4.17.6.4). 

Nitroenamines and related compounds have been used for synthesis of a variety of heterocyclic compounds. Rajappahas summarized the chemistry of nitroenamines (see Section 4.2).140 Ariga and coworkers have developed the synthesis of heterocycles based on the reaction of nitropyridones or nitropyrimidinone with nucleophiles. For example, 2-substituted 3-nitro-pyridines are obtained by the reaction of l-methyl-3,5-dinitro-2-pyridones with ketones in the presence of ammonia (Eq. 10.82).141... 

Model experiments have shown the rates of evaporation of volatiles from vegetated areas. The flux of ammonia and related amino compounds from... 

Many different solvent developers have been used in the separation of sugars and related compounds. Three of these, phenol-water, collidine-water, and 1-butanol-acetic acid-water,27 also commonly employed in the resolution of amino acid mixtures, are widely used. Other commonly used solvent developers are 1-butanol-ammonia-water, 1-butanol-ethanol-water,27 1-butanol-pyridine-water,61 ethyl acetate-acetic acid-water, and ethyl acetate-pyridine-water.26... 

The metallic elements dissolve in liquid ammonia and related amines (e.g. ethylamine C2H5NH) to give solutions which contain solvated electrons in addition to cations. In some solvents there is evidence for equilibria involving alkali anions M-. The solutions are useful reducing agents for the preparation of unusually low oxidation states (e.g. [Ni°(CN4]4-) including anionic compounds of the alkali elements themselves. 

Finally, the formation of derivatives of pyridine from 5-hydroxymethylfurfural and related compounds on treatment with ammonia 0 may be considered in this section on the furan ring. 5-Hydroxymethyl-furfural itself gives 2-hydroxymethyl-5-hydroxypyridine (XLIV) with ammonia, which is presumably formed by opening of the ring in the intermediate aldehyde-ammonia compound followed by closure to give the 6-membered ring. 

Klemer, Almuth. See Micheel, Fritz. Kochetkov, N. K., and Chizhov, O. S., Mass Spectrometry of Carbohydrate Derivatives, 21, 39-93 KORT, M. J., Reactions of Free Sugars with Aqueous Ammonia, 25,311-349 Kowkabany, George N., Paper Chromatography of Carbohydrates and Related Compounds, 9, 303-353 KRANTZ, John C Jr. See Carr, C. Jelleff. 

Ammonia Borane and Related Compounds as Hydrogen Source Materials... 

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