Oxidative transformation of tryptophan to 3-(2-aminophenyl)-2-pyrrolidone and kynurenine

Oxytryptophans 3, which are readily obtained by dye-sensitized photooxygenation of tryptophan followed by acid treatment, undergo a facile N,N′-transacylation to give the 3-(2-aminophenyl)-2-pyrrolidones 4 in the absence of oxygen, whereas in the presence of oxygen 3a was oxidized to kynurenine.     

4-(4-氨基苯基)-3-吗啉酮的合成

以乙醇胺为起始原料,通过环合、Goldberg藕联、还原,三步反应合成利伐沙班关键中间体4-(4-氨基苯基)-3-吗啉酮;该方法反应条件温和、生产成本低、绿色环保,具有良好的工业化前景。     

CuI-catalyzed intramolecular cyclization of 3-(2-aminophenyl)-2-bromoacrylate: synthesis of 2-carboxyindoles

A new approach was described for the synthesis of substituted 2-carboxyindole using 3-(2-aminophenyl)-2-bromo-acrylates through a CuI-catalyzed intramolecular coupling. The reactions were mild, rapid and with good to excellent yields.     

Thermal dehydration of 2-(4-aminophenyl)ethanol

The influence of inorganic nucleophilic agents on the liquid-phase process of thermal dehydration of 2-(4-aminophenyl)ethanol at 200–260°C was investigated. It was found that K₂CO₃, BaCO₃, BaO, CaH₂, and NaOH did not catalyze the dehydration, but the process takes place easily with the formation of 4-aminostyrene in high yield, using KOH in the range of 100–180 mol % with respect to 2-(4-aminophenyl)ethanol.     

N-(2-氨基苯基)-2-喹唑啉酮乙酰胺盐酸盐的合成

本文通过2-溴-N-(2-硝基苯)乙酰胺和取代的喹唑啉酮在NaH催化下发生亲核取代反应,再经过氢化、酸化合成了4个新型常山碱类抗球虫药物-N-(2-氨基苯基)-2-喹唑啉酮乙酰胺盐酸盐(1∶1)。其中,2-溴-N-(2-硝基苯)乙酰胺通过溴乙酰氯与邻硝基苯胺反应制备,取代的喹唑啉酮使用取代的邻氨基苯甲酸与甲酰胺反应合成。所有目标化合物的结构均经1H NMR,IR和HRMS等方法确证。     

Co-synthesis of 1-(3-aminopyridin-2-yl)-1H-benzimidazole and 3-(2-aminophenyl)-3H-imidazo[4,5-b]pyridine

Russian Chemical Bulletin - A new method for the synthesis of N-substituted 3H-imidazo[4,5-b]pyridine via chemical reduction of 1-(3-nitropyridin-2-yl)-1H-benzimidazole in an acidic media was...     

Synthesis and autooxidative transformation of 2-(2-aminophenyl)-4-hydroxy-3-phenyl-1-isoquinolone

2-(2-Aminophenyl)-4-hydroxy-3-phenyl-1-isoquinolone was unexpectedly obtained in the reaction of 3-(-bromobenzyl)-3-bromophthalide with o-phenylenediamine. The isoquinolone in chloroform undergoes autooxidation by air oxygen to give 2-(2-aminophenyl)-3-hydroperoxy-3-phenyl-1,4-dioxo-1,2,3,4-tetrahydroisoquinoline, which is subsequently converted to N-(2-benzamidophenyl)phthalimide. A mechanism is proposed for the rearrangement of the hydroperoxide.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 83–87, January, 1982.     

Preparation of dimethyl (R)- and (S)-2-(2-aminophenyl)-2-hydroxyethylphosphonate from anthranilic acid

An efficient synthesis of both enantiomers of dimethyl δ-amino-β-hydroxyethylphosphonate 6 has been achieved starting from anthranilic acid, through the resolution of dimethyl (±)-2-(2-N,N-dibenzylaminophenyl)-2-hydroxyethylphosphonate 9 with (S)-O-methylmandelic acid. The absolute configuration of the enantiomers 9 was assigned by the Dale and Mosher approach using the extended Newman projections and molecular mechanics.     

The preparation of 5-(2-aminophenyl)-1,3,4-oxadiazole-2(3H)-one and its rearrangement to 3-amino-2,4(1H,3H)-quinazolinedione

When anthranilic acid hydrazide is reacted with 1,1-carbonyldiimidazole inTHF 5-(2-aminophenyl)-1,3,4-oxadiazole-2(3H)-one (4) is formed. It can also be prepared from 1-o-aminobenzoyl-4,4-dimethylsemicarbazide which eliminates methylamine when boiled withDMF. On heating the 5-(2-aminophenyl)-1,3,4-oxiadiazole above its melting point it rearranges to 3-amino-2,4(1H,3H)-quinazolinedione (5).

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Die Darstellung von 5-(2-Aminophenyl)-1,3,4-oxadiazol-2(3H)-on und dessen Umlagerung in 3-Amino-2,4(1H,3H)-chinazolindion

Zusammenfassung Bei der Reaktion von Anthranilsäurehydrazid mit 1,1-Carbonyldiimidazol inTHF wird 5-(2-Aminophenyl)-1,3,4-oxadiazol-2(3H)-on (4) gebildet. Dieses kann auch aus 1-o-Aminobenzoyl-4,4-dimethylsemicarbazid dargestellt werden, welches beim Kochen mitDMF Methylamin eliminiert. Beim Erhitzen von 5-(2-Aminophenyl)-1,3,4-oxadiazol über seinen Schmelzpunkt tritt Umlagerung zu 3-Amino-2,4(1H,3H)-chinazolindion (5) ein.

     

1-三氟乙酰基-2-(4-氨基苯基)肼的合成

以对硝基苯肼和三氟乙酸酐为原料,通过酰化法合成了1-三氟乙酰基-2-(4-硝基苯基)肼,将其还原得1-三氟乙酰基-2-(4-氨基苯基)肼。其结构经^1HNMR,IR,MS和元素分析确证。研究了反应条件对收率的影响及规律,得出较佳的合成条件。     

Spectroscopic properties of ethyl 5-(4-aminophenyl)-3-amino-2,4-dicyanobenzoate

The luminescence properties of ethyl 5-(4-aminophenyl)-3-amino-2,4-dicyanobenzoate (EAADCy) have been studied using steady-state, time-resolved spectroscopic techniques, electrochemical measurements and semiempirical calculations. A series of photophysical measurements and quantum-chemical calculations were carried out with EAADCy in search of an evidence of the occurrence of the aniline group rotation. Studies in different solvents, as well as semiempirical calculations, indicate that conformations with donor and acceptor groups coplanar absorb and emit at wavelengths that are longer than those observed for donor–acceptor groups oriented orthogonally. The values of the dipole moments of planar and perpendicular form of molecule under study were estimated from solvatochromic shifts of absorption and fluorescence spectra as a function of the solvent dielectric constant and refractive index. Experimentally calculated changes of the dipole moment values are in fair agreement with semiempirical computational predictions.     

Bromination of sydnones. II Bromination of 3-(2-aminophenyl)sydnone and related compounds

Bromination of 3-(2-aminophenyl)sydnone 2 under a variety of conditions is reported. The products obtained are interrelated by a series of subsequent reactions. One major product is the bromoaryl compound 8, the first example of bromination on the aryl rather than sydnone ring when the two are in competition. Surprisingly, bromoaminosydnone 9, prepared from its nitro analogue, was not among the products obtained by direct bromination of 2.     

Crystalline copolyamides of β-(4-aminophenyl)-propionic acid and caprolactam

Methyl β-(4-aminophenyl)propionate was prepared and converted to a crystalline polyamide. The copolymerization of β-(4-aminophenyl)propionic acid or its methyl esters with caprolactam resulted in polyamides having wide ranges of crystallinity and thermal stability, depending on the chemical composition. Copolymers with 10, 50, 85, 90, and 95 mole-% of caproamide sequences were shown by x-ray and differential scanning calorimetry to be semicrystalline. The composition and thermal stability of the polyamides were studied by infrared spectroscopy and thermogravimetric analysis, respectively.     

Coordination compounds of N-(2-aminophenyl)- and N-(3-aminophenyl)pyridine-2′-carboxamide with cobalt(II) and cobalt(III). The nature of amide deprotonation induced by cobalt(III) in acidicpH

New complexes of the general formulae CoL ₂ X·nH₂O (X=Cl, Br, I, NCS, NO₃ andn=0, 1, 2 or 3), Co₂ L ₂ X ₃·EtOH (X=Cl, Br, I, NCS), Co(DH)X ₂ (X=NCS, NO₃) and Co(DH)₂ X ₂ (X=NCS, I) have been prepared, whereLH=N-(2-aminophenyl)pyridine-2-carboxamide andDH=N-(3-aminophenyl)pyridine-2-carboxamide. The compounds were characterized by X-ray powder patterns, conductivity measurements, thermogravimetric analysis, magnetic properties as well as by IR, ligand field and¹H-NMR spectroscopy. In the presence of oxygen,LH undergoes a cobalt(III) ion promoted amide hydrogen ionization in thepH region 4–6.

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Koordinationsverbindungen von N-(2-aminophenyl)- und N-(3-aminophenyl)pyridin-2-carboxamid mit Cobalt(II) und Cobalt(III). Die Natur der Deprotonierung von Amiden induziert von Cobalt(III) in saurem Medium

Zusammenfassung Neue Komplexe der allgemeinen Formeln CoL ₂ X·nH₂O (X=Cl, Br, I, NCS, NO₃ undn=0, 1, 2, 3), Co₂ L ₂ X ₃·EtOH (X=Cl, Br, I, NCS), Co(DH)X ₂ (X=NCS, NO₃) und Co(DH)₂ X ₂ (X=NCS, I) wurden dargestellt mit LH=N-(2-aminophenyl)pyridin-2-carboxamid undDH=N-(3-aminophenyl)pyridin-2-carboxamid. Die Verbindungen wurden mittels Röntgenstrukturanalyse, Leitfähigkeitsmessungen, thermogravimetrischen Analysen, magnetischen Eigenschaften sowie mit IR-, Ligandenfeld- und¹H-NMR-Spektroskopie charakterisiert. In Gegenwart von Sauerstoff unterliegtLH einer Cobalt(III)ion-induzierten Amidwasserstoffionisierung impH-Bereich 4–6.

     

Co-crystal structure of mixed molecules of methyl 2-(3-chloro-4-methyl-2-oxo-2H-chromen-7-yloxy)acetate and 2-(2-aminophenyl)benzothiazole

A co-crystal is obtained in a methanolic solution from methyl 2-(3-chloro-4-methyl-2-oxo-2H-chromen-7-yloxy)acetate and 2-(2-aminophenyl)benzothiazole. In the crystal these molecules are connected via usual N-H…O and weak C-H…O H-bonds. The co-crystals are very stable.