Amino aromatic

C) Amino-aromatic sulphonic acids. Sulphanilic acid. 

Amino-aromatic carboxylic acids Unsaturated aromatic acid... 

C) AMINO AROMATIC SULPHONIC ACIDS. Sulphanilic or p-amino-benzene sulphonic acid, NH2CJH4SO3H. 

These salts are by far the most readily prepared derivatives (having sharp m.ps.) of the amino-aromatic sulphonic acids. 

Amino Aromatic Sulphonic Acids. Benzylthiouronium salts (p. 384). 

Amino aromatic sulphonic acid (sulphanilic acid)... 

Synthesis and Properties. Polyquinolines are formed by the step-growth polymerization of o-aminophenyl (aryl) ketone monomers and ketone monomers with alpha hydrogens (mosdy acetophenone derivatives). Both AA—BB and AB-type polyquinolines are known as well as a number of copolymers. Polyquinolines have often been prepared by the Friedlander reaction (88), which involves either an acid- or a base-catalyzed condensation of an (9-amino aromatic aldehyde or ketone with a ketomethylene compound, producing quinoline. Surveys of monomers and their syntheses and properties have beenpubhshed (89—91). 

Chromone, 2-alkylamino-5,8-dimethoxy-synthesis, 3, 717 Chromone, 2-amino-aromaticity, 3, 714 tautomerism, 3, 644... 

An unusual by-product was obtained in small yield in palladium-catalyzed reduction of 2-amino-4,5-dimethoxyindanone hydrochloride, The reduction was done in two stages first, a rapid absorption of 1 mol of hydrogen at 38 C to give the amino alcohol, and then a much slower reduction in the presence of HCIO4 at 70 "C. The rearranged by-product was shown to arise from attack of acid on the amino alcohol (50), Resistance to hydrogenolysis is characteristic of / -amino aromatic alcohols (56), a fact that makes reduction of aromatic oximino ketones to amino benzyl alcohols a useful synthetic reaction. 

Toxicophores [33] (polycyclic aromatic and polycyclic planar systems, nitro-and amino-aromatics). 

Any nitro- or amino-aromatic compound may be considered a potential source of interference until demonstrated otherwise. For example, DN-111 in benzene was processed in the usual manner. During the reduction step a pink color developed which was insoluble in petroleum ether addition in proper sequence of the dye-producing reagents resulted in the development of a deep purple color within 10 minutes. 

A chiral catalyst consisting of Irans-RuC]2(xy]binap)(daipen) and (CH3)3COK in 2-propanol effects asymmetric hydrogenation of a-, / -, and y-amino aromatic ketones [128]. Hydrogenation of 2-(dimethylamino)acetophenone catalyzed by the (R)-XylBINAP/(R)-DAIPEN-Ru complex [(R,R)-31D] gives the R amino alcohol in 93% ee (Fig. 32.36). The optical yield is increased up to 99.8%, when... 

Burley, S. K., and Petsko, G. A. (1986). Amino-aromatic interactions in proteins. FEBS Lett. 203, 139-143. 

Note In order to ensure that the extinctions recorded exclusively refer to folic acid (I), and also that they do not necessarily include a contribution from a free-primary-amino-aromatic-moiety obtained from a decomposition product, a blank estimation is always performed with the unreduced solution and an appropriate correction is applied. The colour thus corresponds to a definite quantity of C16H19OfiN7. Thus, we have ... 

Figure 4.46 (a) Charge transfer in excited states of hydroxy- and amino-aromatics, (b) Xanthone offers two potential protonation sites... 

High yields and enantiopurity have been realized by a highly diastereoselective MPV reduction of protected a-amino aromatic ketones using catalytic amounts of aluminium isopropoxide. The high anti selectivity resulted from the chelation of the (g) nitrogen anion to the aluminium. In contrast, high syn selectivity was obtained with a-alkoxy ketones and other compounds via Felkin-Ahn control.354... 

A pharmaceutical intermediate was initially produced at a scale of 500 kg (product) per batch in a 2.5 m3 reactor. The reaction was the condensation of an amino-aromatic compound with an aromatic chloride to form a di-phenyl amine by elimination of hydrochloric acid. This acid was neutralized in situ by sodium carbonate, forming water, sodium chloride, and carbon dioxide. The manufacturing procedure was very simple The reactants were mixed at 80 °C, a temperature above the melting point of the reaction mass. Then the reactor was heated with steam in the jacket to a temperature of 150 °C. At this temperature, the steam valve had to be closed and the reaction left to proceed for a further 16 hours. During this time, the temperature increased to a maximum of 165 °C. Several years later, the batch size was increased to 1000 kg per batch in a 4 m3 reactor. Two years after this a further increase to 1100 kg was decided. 

Fig. 20. Schematic view of the antihyperlipoproteinemic compound bezafibrate bound to deoxyhemoglobin A in the central cavity of the tetramer. The protein-ligand interactions include an amino-aromatic interaction involving asparagine-108 and an aromatic-aromatic interaction involving tryptophan-37, . Reproduced with permission from Perutz et al. (1986).

Like the other weakly polar interactions, amino-aromatic interactions are a mechanism of protein-ligand binding. Perutz et al. (1986) described a series of X-ray crystallographic studies of drugs and peptides bound to deoxy-Hb A. They characterized an amino-aromatic interaction between the 8+ N8—H group of asparagine-108 with the 8 7r-electron cloud of one of the phenyl rings of bezafibrate (see Fig. 20). 

Fig. 25. Stereodrawings of the two conformations of arginine-45 of carbon monoxy-myoglobin from sperm whale, (a) Conformation I, which is comparable to the conformation normally observed in metmyoglobin from sperm whale, (b) Conformation 2, which is stabilized by an amino-aromatic interaction between arginine-45 and phenylalanine-43.

Fic. 26. Amino-aromatic sandwich detected in bovine pancreatic trypsin inhibitor. The side chain of tyrosine-34, indicated by its van der Waals surface, is sandwiched between the main-chain N—H group of glycine-37 and ND2—H amino group of asparagine-44. The distance between the two hydrogen atoms is 5.2 A. 

Quenching of triplet states of aromatic hydrocarbons and carbonyl compounds by inorganic anions (I-, Br , NOj, Cl-) Quenching of excited aromatic molecules by aromatic hydrocarbons, nitriles, methoxy- and amino-aromatics Quenching of excited aromatic molecules by methoxy and amino-aromatics Quenching of excited cyanoanthracenes, by aromatic hydrocarbons, methoxy-aromatics and sulfides... 

---