Amines condensation

Aston MS Refinex Onyx quaternized (cationic) fatty amine condensate... 

The mechanism of the original Knorr pyrrole synthesis entails in situ reduction of the oxime moiety to an amine, condensation with the second carbonyl compound, and cyclization with loss of a second molecule of water to give a pyrrole for example, 10 + 11 to 12. Several studies have demonstrated that different pathways and pyrrole products obtain depending on the substrates. 

In 1911, Ame Pictet and Theodor Spengler reported that P-arylethyl amines condensed with aldehydes in the presence of acid to give tetrahydroisoquinolines. Phenethylamine 6 was combined with dimethoxymethane 7 and HCl at elevated temperatures to give tetrahydroisoquinoline 8. Soon after, the Pictet-Spengler reaction became the standard method for the formation of tetrahydroisoquinolines. 

When the filming amine condenses, the hydrophilic polar radical of the molecule (the head) adsorbs onto the metal surface and the hydrophobic, long chain (the tail) is directed at a 90° angle of inclination away from the metal surface. Provided the feed rate is adequate, the critical concentration is eventually reached and a continuous monomolecular surface film is formed. At this stage, the physical size of the interstices between the polar groups is smaller than the molecules of water, carbon dioxide, or oxygen, and these molecules are thus physically prevented from reaching the metal surface. 

Like alcohols, amines condense with carboxylic acids ... 

Peroxidase and laccase enzymes were used to catalyze the decarboxylation of various tetrahydroisoquinoline-1-carboxylic acids to give high yields of the corresponding 3,4-dihydroisoquinolines (204). Compounds such as 125 (Scheme 29) are derived from Pictet-Spengler ring closure via a-keto acid and aryl amine condensation and are of biogenetic importance. The possible relevance of iso-... 

Hansa yellow org chem Group of organic azo pigments with strong tinting power, but poor opacity in paints used where nontoxIcIty Is Important. han-sa yel o ) Hantzsch synthesis org chem The reaction whereby a pyrrole compound is formed when a p-ketoester, chloroacetone, and a primary amine condense. hansh, sin-tha-sas ... 

The initiating reaction between aldoses and amines, or amino acids, appears to involve a reversible formation of an N-substituted aldosyl-amine (75) see Scheme 14. Without an acidic catalyst, hexoses form the aldosylamine condensation-product in 80-90% yield. An acidic catalyst raises the reaction rate and yet, too much acid rapidly promotes the formation of 1-amino-l-deoxy-2-ketoses. Amino acids act in an autocat-alytic manner, and the condensation proceeds even in the absence of additional acid. A considerable number of glycosylamines have been prepared by heating the saccharides and an amine in anhydrous ethanol in the presence of an acidic catalyst. N.m.r. spectroscopy has been used to show that primary amines condense with D-ribose to give D-ribopyrano-sylamines. ... 

Some of the aldehyde-amine condensation products have been recommended as ingredients of nondetonating, deflagrating, expl compns (similar in properties to black powder) for use in the delay combustion-train devices of fuzes. Other ingredients of such compns are non-explosive, such as alkali metal nitrates and charred carbonaceous compounds(Ref 1)... 

Amines, Condensation With Aromatic Chlorine Compounds. Amines can be condensed with aromatic Cl den vs and the resulting compds... 

J.P.Picard J.L.Boivin, CanjChem 29, 223(1951) CA 45, 9469(1951) 7)R.Renaud L.C.Leitch, CanlChem32, 549(1954) Azomethines or Scniff Bases, See under Aldehyde-Amine Condensation Products,... 

During the formation of aldehydes or ketones with active MnCb, sometimes an amine condenses intramolecularly resulting in the formation of iinines.49... 

A benzylic alcohol is selectively oxidized with Mn02 in the presence of a primary amine. The amine condenses intramolecularly with the resulting aldehyde, leading to the formation of ... 

Mechanistically, this novel process is apparently a Type II MCR, characterized by complex equilibria among the three components and various intermediates, which give the amine condensation products 41 via an irreversible C-C bond-forming step (Scheme 7.7). Thus, condensation between the amine 38 and carbonyl 39... 

Several mechanisms have been reported for pyrazine formation by Maillard reactions (21,52,53). The carbon skeletons of pyrazines come from a-dicarbonyl (Strecker) compounds which can react with ammonia to produce ot-amino ketones as described by Flament, et al. (54) which condense by dehydration and oxidize to pyrazines (Figure 6), or the dicarbonyl compounds can initiate Strecker degradation of amino acids to form ot-amino ketones which are hydrolyzed to carbonyl amines, condensed and are oxidized to substituted... 

The dyes should not contain any inorganic byproducts or diluents. The preferred anionic dyes include salts formed by using ammonia as cation, or special tetraalkylamines, e.g., C.I. Solvent Orange49, (Orange II see Section 5.3) with an amine condensate as cation. 

The Knorr pyrrole synthesis consists of a ketone and amine condensing to give an enamine, followed by intramolecular cyclisation of this enamine onto the remaining ketone. 

Reaction A Sugar-amine condensation Reaction B Amadori rearrangement... 

Reaction G Aldehyde-amine condensation and formation of heterocyclic nitrogen compounds... 

Scheme 2.1 Sugar-amine condensation to form N- substituted glycosylamine...

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