Amino group compounds

Use of H2 and Pd/C provides the transformation of a nitro into an amino group. Compound 50 cannot be synthesized by treatment with LiAlH4, because the carbamate group would be attacked, too. 

A weakly ionized phenolic hydroxyl group at the 4 -position is essential for optimum hormonal activity. Replacement of the 4 -hydroxyl with an amino group (compound 39 in Table 34.2) ... 

In dry white winemaking, juice extraction methods influence the amino group compound and protein concentration in must. Slow pressing and skin maceration, which favor the extraction of skin constituents, increase their concentration (Dubourdieu et al., 1986). 

Azo-compounds can be obtained by reduction of nitro-compounds, or by oxidation of hydrazo-compounds. They are usually prepared, however, by reacting a phenol or amine with a diazonium salt. The coupling usually takes place in the position para to the hydroxyl or amino group, but if this position is occupied it goes to the ortho position, e.g. 

The procedure is not usually applicable to aminosulphonic acids owing to the interaction between the amino group and the phosphorus pentachloride. If, however, the chlorosulphonic acid is prepared by diazotisation and treatment with a solution of cuprous chloride in hydrochloric acid, the crystalline chlorosulphonamide and chlorosulphonanilide may be obtained in the usual way. With some compounds, the amino group may be protected by acetylation. Sulphonic acids derived from a phenol or naphthol cannot be converted into the sulphonyl chlorides by the phosphorus pentachloride method. 

Compounds containing two primary amino groups attached to a benzene ring can be prepared by the reduction of dinitro compounds and of nitroanilines, usually with tin or stannous chloride and hydrochloric acid or with iron and very dilute hydrochloric acid. / ara-diamines may also be obtained by the reduction of aromatic amino-azo compounds (e.g., p-aminodimethylanihne from methyl orange, see Section IV,78). p-Phenylenediamine may also be prepared from p-nitroacetanilide reduction with iron and acid yields p-amino-acetaniUde,.which may be hydrolysed to the diamine. 

Acetates may also be prepared by adding acetic anhydride to somewhat dilute solutions of compounds containing hydroxyl (or amino) groups in aqueous caustic alkahs. The amount of alkali used should suffice to leave the hquid shghtly basic at the end of the operation, so much ice should be added that a little remains unmelted, and the acetic anhydride should be added quickly. 

Periodic acid has a selective oxidising action upon compounds having two hydroxyl groups or a hydroxyl and an amino group attached to adjacent carbon atoms and is characterised by the cleavage of the carbon - carbon bond (Malaprade reaction) ... 

Other substituents which belong with this group have already been discussed. These include phenol, anisole and compounds related to it ( 5.3.4 the only kinetic data for anisole are for nitration at the encounter rate in sulphuric acid, and with acetyl nitrate in acetic anhydride see 2.5 and 5.3.3, respectively), and acetanilide ( 5.3.4). The cations PhSMe2+, PhSeMe2+, and PhaO+ have also been discussed ( 9.1.2). Amino groups are prevented from showing their character ( — 7 +717) in nitration because conditions enforce reaction through the protonated forms ( 9.1.2). 

The 3-amino group brings a second nucleophilic center in these structures thus 2-imino-3-amino-4-methyl-4-thia201ine (409) reacts with methyl diloroformate to give the bicyclic compound (410) (Scheme 234). Other thiazolo-s-triazoles of the [3.2-l>] type have been obtained by... 

The amino group on sulfur in 133 may be replaced by substituted amines with evolution of ammonia to give compounds such as 134 (Scheme 68) (316). 

However, prior protective acetylation of the amino group leads to a good yield of the 5-nitro compound [2-acetamido-4-methyl-5-nitroselenazole, m.p. 185 C (19)j. Similarly. 2-diethylamino-4-methy)-selenazole with nitric acid gives the. 5-nitro derivative [vellow needles, m.p. 93°C (26)],... 

Compounds of this type possess a definite Aj-selenazoline structure, while homologous compounds with at least one labile hydrogen on the 2-amino group can exist as a tautomeric equilibrium (Scheme 64). 

Amino groups rank rather low in seniority when the parent compound is identified for naming purposes Hydroxyl groups and carbonyl groups outrank ammo groups In these cases the ammo group is named as a substituent... 

Dipeptide (Section 27 7) A compound in which two a amino acids are linked by an amide bond between the amino group of one and the carboxyl group of the other... 

Historically, the discovery of one effective herbicide has led quickly to the preparation and screening of a family of imitative chemicals (3). Herbicide developers have traditionally used combinations of experience, art-based approaches, and intuitive appHcations of classical stmcture—activity relationships to imitate, increase, or make more selective the activity of the parent compound. This trial-and-error process depends on the costs and availabiUties of appropriate starting materials, ease of synthesis of usually inactive intermediates, and alterations of parent compound chemical properties by stepwise addition of substituents that have been effective in the development of other pesticides, eg, halogens or substituted amino groups. The reason a particular imitative compound works is seldom understood, and other pesticidal appHcations are not readily predictable. Novices in this traditional, quite random, process requite several years of training and experience in order to function productively. 

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