Synthesis of the carboline disaccharide domain of shishijimicin A

A synthetic route to the carboline disaccharide domain (2) of shishijimicin A (1) has been developed. The convergent synthesis relies on a novel application of the Reetz-Mu?ller-Starke reaction to form the central, sulfur-bearing quaternary carbon center and addition of the carboline structural motif as a dianion to a disaccharide aldehyde fragment.     

Synthesis of isatin-N-mannich bases

The synthesis of a series of isatin-N-Mannich bases derived from isatin, 5-methyl and 5-bromoisatins as the active hydrogen component and dimethylamine, diethylamine, morpholine, piperidine, N-ethylcyclohexylamine, 3-azabicyclo[3.2.2]nonane and 3-aza-bicyclo[3.2.1]octane as the secondary amine moiety is described. These compounds are to be screened for their pharmacological properties.     

Synthesis of carboranes containing nucleoside bases

The carboranes containing uridine derivatives ( 9a,b,c ), and purine base ( 8 ) were prepared by the reaction of decaborane with the corresponding acetylene precursors ( 3a, 3b, 2c and 5b , respectively).     

Synthesis of pyridine bases from vinylacetylene

Summary During condensation with ammonia over cadmium catalysts at 400°, a secondary vinylethynylcarbinols are decomposed to aldehydes and vinylacetylene. Acetaldehyde formed in the process undergoes the Chichibabin reaction with ammonia to give - and -picolines and 2,4-lutidine; propionaldehyde gives 2-ethyl-3,5-dimethyl-pyridine.     

Synthesis of mannich bases of bioactive benzylphenols

2,4-Bis(1,1-dimethyl)-6-[(4-methoxyphenyl)methoxymethyl]phenol ( 4 ), prepared by oxidation of 2,4-bis(1,1-dimethylethyl)-6-[(4-methoxyphenyl)methyl]phenol ( 1 ) with silver oxide in methanol, reacts with secondary amines in boiling toluene to give Mannich bases ( 6 ) related to the biologically active o-benzylphenol. Mannich basis of the isomeric p-benzylphenol ( 7 ) were prepared by reaction of amines with the p-quinone methide formed by oxidation of 7 .     

Synthesis of pyridine bases from piperidine derivatives

The corresponding substituted pyridines are obtained in 40–90% yields when N-alkyl-substituted piperidines, gD⁴-piperideines, and secondary and tertiary -piperidols are heated at 240–270C with pyridine N-oxide.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 787–789, June, 1977.     

Synthesis of novel Mannich bases and hybrid Mannich bases related to isoindolin-1,3-dione

Treatment of isoindolin-1,3-dione ( 1 ) with formalin and the appropriate amine or diamine afforded new N-Mannich bases and bis-(Mannich bases) 2 to 6 . The use of the appropriate hydrazide or dihydrazide as the amine component in the Mannich reaction with 1 led to Mannich bases and bis-(Mannich bases) incorporating a hydrazide moiety. The synthetic potential of sec-Mannich bases as precursors in synthesis of hybrid Mannich bases incorporating 1 was described. The N-alkylation of 1 with ketonic Mannich bases was investigated.     

Synthesis and biological activities of novel chiral fluorinated β‐carboline derivatives

A series of unreported chiral β‐carbolines 4 with trifluoromethyl group at position‐1 and chiral carboxamide chains or amino acid ester chains at position‐3 has been designed and synthesized. The results of bioassay in vitro show that compounds 4e, 4i and 4k show 78.8%, 84.0% and 78.9% inhibition on monoamine oxidase, in 1 mmol/L, respectively, and compound 4e also exhibit 60.9% inhibitory activity on tumor lung cell A‐549 in 10^?5 mmol/L. In view of different configuration, the inhibitory activity on monoamine oxidase of S‐enantiomer of the target compound is better than that of R‐enantiomer.     

Synthesis and spectroscopic studies of new Schiff bases

Five novel Schiff bases have been prepared from o-formylphenoxyacetic acid and a series of aminothiazoles to form a number of potentially biologically active compounds. The structures of these Schiff bases have been characterized using IR and (1)H-and (13)C-NMR spectroscopy.     

Synthesis and properties of highly lipophilic phosphazene bases

Twelve novel phosphazene bases (X-C₆H₄-NN-C₆H₄-NPR₃) with an unusual combination of properties – high lipophilicity of both neutral and charged forms, lack of localized charges in the cations, and strong spectral changes upon protonation/deprotonation – were synthesized using the Staudinger reaction and characterized by UV–Vis spectra, pK_a values and lipophilicities (logP values). The bases could potentially be useful as working agents in optical sensors and acid-base indicators for lipophilic membranes.     

Isolation of a new carboline alkaloid from Trigonostemon lii

A new carboline alkaloid, 1-(7-methoxy-quinolinyl-4′-yl)-3,4-dihydro-β-carboline (1), was isolated from the leaves and twigs of Trigonostemon lii Y.T. Chang, together with three known ones, trigonostemonines C and D (2 and 3), and trigonoliimine A (4). Their structures were elucidated by spectroscopic analyses, including 2D-NMR techniques.     

Synthesis of Schiff bases by condensation of hetarylcarboxaldehydes withp-phenetidine

Summary Treatment of quinolinecarboxaldehydes and their derivatives withp-ethoxyaniline yields in a one-step reaction a series of new Schiff bases in 47–73% yield. The products [quinoline-2-, 6-methylquinoline-2-, quinoline-4-, quinoline-8-, and acridine-9-N-(p-ethoxyphenyl)formimidoyl], have been fully characterized.

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Synthese von Schiffschen Basen durch Kondensation von Hetarylaldehyden mitp-Phenetidin

Zusammenfassung Umsetzung von Chinolinaldehyden und deren Derivaten mitp-Ethoxyanilin liefert in einer Einstufenreaktion neue Schiffsche Basen in 47–73%iger Ausbeute. Alle Produkte [Chinolin-2-, 6-Methylchinolin-2-, Chinolin-4-, Chinolin-8- und Acridin-9-N-(p-ethoxyphenyl)formimidoyl] wurden voll charakterisiert.

     

三氮唑类席夫碱的合成及其荧光性能

近年来,Schiff碱因其结构的多样化以及具有光、电、磁等物理材料性能[1-3]的配位化学性能[4-5]等引起人们的关注,同时一些特殊结构的Schiff碱的合成和性质研究具有更为重要的理论意义和应用价值.     

Synthesis and biological activity of sulfur-containing aryl-aldehyde Schiff bases

A series of chemically modified aryl-aldehyde Schiff bases has been synthesized and tested for their antioxidant activity and radiation protection. We observed that disulfide-containing aryl-aldehyde Schiff base 6c exhibited potent free radical scavenging, antioxidation, and radioprotection activities.     

用酮作为酸性组分的MANNICH碱的合成

本文综述了用鬲作为酸性组分合成MANNICH碱的最近进展。β-脂氨基酮、β-芳氨基酮的合成和分子内MANNICH反应。     

Synthesis of 1,3-diazacyclanes by the benzoylation of bis-schiffs bases

Conclusions Benzoylation of the bisazomethines R-CH=N(CH₂)_nN=CH-R (R=i-C₃H₇, Ph; n=3–6.8) affords NN-dibenzoyl-2-R-1,3-diazacycloalkanes and open-chain amides. The yields of 2-R-1,3-diazacycloalkanes are at a maximum when n=2 and 3, decreasing rapidly as n increases.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 7, pp. 1612–1615, July, 1985.     

Synthesis of novel chiral compounds of purine and pyrimidine bases

The physiologically active groups such as purine and pyrimidine bases are introduced to the asymmetric ynthesis. The optically pure compounds bearing purine and pyrimidine bases (5a—5e) were prepared via the asymetric Michael addition reaction of purines and pyrimidines as Michael donators with the chiral source 5-(R)-[(1R, 2S, 5R)-menthyloxy]-2(5H)-furanone (3a), which was prepared from the natural chiral auxiliary (-)-menthol. The synthetic method was studied in detail and the new compounds were identified on the basis of their analytical data and spectroscopic data, such as [α]_D~(20), IR, UV, ~1H NMR, ~(13)C NMR and MS. The absolute configuration of 5a was established by X-ray crystallography. The results provided an efficient synthetic route to chiral purines and pyrimidine analogues, and offered chiral sources for further research on the physiologically active compounds of chiral nucleotides.