A Betti reakció alkalmazásai = New applications of the Betti reaction

A háromkomponensű módosított Mannich reakcióban aldehid komponensként szalicilaldehidet alkalmazva 1-[aminometil-(2-hidroxifenil)]-2-naftolt állítottunk elő, melyből dominó gyűrűzárási reakciók segítségével naftoxazino[3,4-c][1,3]benzoxazin származékokat szintetizáltunk, míg alifás aldehidek alkalmazásával 1-aminoalkil-2-naftol-származékokat szintetizáltunk. Az aminonaftol származékokat ekvivalens mennyiségű X-szubsztituált benzaldehidekkel reagáltatva 1-alkil-3-aril-naftoxazinokat szintetizáltunk, melyek CDCl3-ban, 300 K-en háromkomponensű gyűrű-lánc tautomer elegy formájában voltak jelen. A módosított Mannich reakcióban, dihidroizokinolin származékok, mint gyűrűs iminek alkalmazásával 1-(hidroxinaftil)-izokinolin származékokat állítottunk elő, melyeknek formaldehides, foszgénes, p-nitro-benzaldehides valamint p-klór-fenilizotiocianátos gyűrűzárásával különböző 8-szubsztituált naftoxazino[4,3-a][1,3]izokinolinokat szintetizáltunk. A háromkomponensű módosított Mannich reakcióban királis aminkomponensként az (R)-(+)-1-(1-naftil)-etilamin, illetve az (R)-(+)-1-(2-naftil)-etilamin alkalmazásával új nemracém aminonaftolokat állítottunk elő, melyeket királis katalizátorként alkalmazva, a választott benzaldehid dietil-zink modellreakcióban akár 92 %-os enentioszelektivitást is el tudtunk érni. A tudományos kutatómunkából 4 megjelent és 2 közlésre előkészített publikáció született, az eredményeket pedig 6 nemzetközi és 2 hazai konferencián mutattuk be. | Through the use of salicylaldehyde in the three-component modified Mannich reaction, 1-[aminomethyl-(2-hydroxyphenyl)]-2-naphthol was prepared, and then transformed through domino ring-closure reactions to naphthoxazino[3,4-c][1,3]benzoxazine derivatives. Another new extension of the Betti reaction is the use of aliphatic aldehydes, whereby novel 1-aminoalkyl-2-naphthol derivatives were prepared. The reactions of these aminonaphthols with X-substituted benzaldehydes led to 1-alkyl-3-aryl-naphthoxazines, which proved to be three-component tautomeric mixtures in CDCl3 at 300 K. When dihydroisoquinolines were reacted with 2- or 1-naphthol, the 1-(hydroxynaphthyl)isoquinoline derivatives obtained were readily transformed to the corresponding 8-substituted-naphthoxazino[4,3-a][1,3]isoquinolines via their ring closures with formaldehyde, phosgene, p-nitrobenzaldehyde and p-chlorophenyl isothiocyanate. The application of (R)-(+)-1-(1-naphthyl)ethylamine and (R)-(+)-1-(2-naphthyl)ethylamine as chiral amines furnished new, non-racemic aminonaphthols, depending on the reaction conditions, when these aminonaphthols were used as chiral catalysts in the addition of diethylzinc to benzaldehyde, the ee values of the main enantiomer could be increased up to 92%. This research work has so far resulted in 4 publications and a further 2 are already under preparation for publication. The results have been presented at 8 conferences held in different countries

TRAGLAST DER VERSTEIFTEN, SCHUBBEANSPRUCHTEN STEGBLECßES (EXPERIMENTELLE UNTERSUCHUNGEN UND NÄHERUNGSBERECHNUNG)

In the years 1982-83 in the Department of Steel-Structures of the Technical Uni- versity of Budapest altogether 14 experiments were carried out to investigate the postcritical behaviour of armed, shear stressed web plate and to gain more information about the influence of the stiffness parameters of the longitudonal rib. The results of these experiments and a new method for calculation are described in the article

Synthesis of Bioactive Aminomethylated 8-Hydroxyquinolines via the Modified Mannich Reaction

8-hydroxyquinoline (oxine) is a widely known and frequently used chelating agent, and the pharmacological effects of the core molecule and its derivatives have been studied since the 19th century. There are several synthetic methods to modify this core. The Mannich reaction is one of the most easily implementable examples, which requires mild reaction conditions and simple chemical reagents. The three components of the Mannich reaction are a primary or secondary amine, an aldehyde and a compound having a hydrogen with pronounced activity. In the modified Mannich reaction, naphthol or a nitrogen-containing naphthol analogue (e.g., 8-hydroxyquinoline) is utilised as the active hydrogen provider compound, thus affording the formation of aminoalkylated products. The amine component can be ammonia and primary or secondary amines. The aldehyde component is highly variable, including aliphatic and aromatic aldehydes. Based on the pharmacological relevance of aminomethylated 8-hydroxyquinolines, this review summarises their syntheses via the modified Mannich reaction starting from 8-hydroxyquinoline, formaldehyde and various amines

Syntheses, transformations and applications of aminonaphthol derivatives prepared via modified Mannich reactions

A special alteration is the three-component modi fi ed Mannich reaction (mMR), in which formaldehyde is replaced by an aromatic aldehyde, the secondary amine by ammonia, and the C e H acid by an electron-rich aromatic compound such as 1- or 2-naphthol, quinolinol or isoquinolinol. Based on this, it can be interpreted as a formal Mannich reaction. Starting from ammonia, benzaldehyde, and 2-naphthol in this mMR, 100 years ago, Mario Betti reported the straightforward synthesis of 1,3-diphenylnaphthoxazine in methanol. Acidic hydrolysis of the ring compound produced led to 1-aminobenzyl-2-naphthol. The aminonaphthol product became known in the literature as a Betti base, and the protocol as the Betti reaction. 3 e 5 This reaction has subsequently been extended by using different N sources, the order and character of which (ammonia, amine or amide) greatly determine the reaction conditions and the method of isolation of the Mannich product. 6 On the other hand, the use of non-racemic amines has opened up a new area of ap- plication of enantiopure aminonaphthols as chiral catalysts in enantioselective transformations

A Betti reakció új alkalmazásai = New applications of the Betti reaction

A módosított Mannich reakcióban, dihidroizokinolin származékok, mint gyűrűs iminek alkalmazásával 1-(hidroxinaftil)-izokinolin származékokat állítottunk elő, melyeknek formaldehides, foszgénes, p-nitro-benzaldehides valamint p-klór-fenilizotiocianátos gyűrűzárásával különböző 8-szubsztituált naftoxazino[4,3-a][1,3]izokinolinokat szintetizáltunk. Az új policiklusok konformációanalízisét különböző NMR mérésekkel végeztük el és ab initio számításokkal támasztottuk alá. A tudományos kutatómunkából 1 közlésre előkészített publikáció született. | When dihydroisoquinolines were reacted with 2- or 1-naphthol, the 1-(hydroxynaphthyl)-isoquinoline derivatives obtained were readily transformed to the corresponding 8-substituted-naphthoxazino[4,3-a][1,3]isoquinolines via their ring closures with formaldehyde, phosgene, p-nitrobenzaldehyde and p-chlorophenyl isothiocyanate. The conformational analysis of the new policyclic compounds was performed by NMR measurements and was supported by ab initio calculations. This research work has resulted in 1 publication which has been submitted