Search results for "substitut"
showing 10 items of 1337 documents
Antimykotische wirkstoffe. XXI. Aliphatisch und alicyclisch substituierte chlor-diallylamino-1l,3,5-triazine
1988
Aus der nucleophilen Substitution eines Chloratoms in 2,4-Dichlor-6-(diallylamino)-1,3,5-triazin (1) durch Amine (2a-g) gehen die Alkylamino- und Cycloalkylamino-chlor-(diallylamino)-1,3,5-triazine (3a-g) hervor. Von den zur Untermauerung des Strukturtyps 3 herangezogenen spektroskopischen Daten sind besonders charakteristisch die durch das 1,3,5-Triazinringsystem hervorgerufene IR-Bande bei 800 cm−1, die den Allylgruppen zuzuordnenden vier 1H-NMR-Signale zwischen 4,1–6,1 ppm und das beim massenspektroskopischen Abbau auftretende Rumpfkation m/e 158. Auffallend ausgepragt sind in Verbindungsklasse 3 antimykotische, trichomonazide und herbizide Wirksamkeit. By nucleophilic substitution of on…
BODIPY Dyes Functionalized with Pendant Cyclic and Acyclic Polyamines
2013
The synthesis and characterization of a series of BODIPY derivatives substituted with acyclic and cyclic polyamines, in particular, cyclen and homocyclen, are reported. The 19F NMR, UV/Vis, and fluorescence spectroscopic data of these compounds are discussed. One compound was found to be very selective for CuII ions, which makes it a very promising system for CuII detection.
ChemInform Abstract: The Chemistry of Unsaturated Nitrogen-Heterocyclic Compounds Containing Carbonyl Groups
2010
Publisher Summary Most hydroxy-substituted azaheteroaromatic compounds exist predominately in the NH/carbonyl tautomeric form, and these compounds have been widely discussed. This chapter provides an overview of azaheteroaromatic compounds and I-azetin-4-ones—these are those azaheterocycles that contain in the ring at least one carbonyl group and one or two nitrogen atoms in the form of C=N or N=N bonds. Many of these compounds are unstable but their importance as reactive intermediates is established, and many of them could be used as synthons in the preparation of pharmacologically active compounds. The chapter describes the free existence of I-azetin-4-one and the nucleophilic substituti…
The Chemistry of Unsaturated Nitrogen–Heterocyclic Compounds Containing Carbonyl Groups
1993
Publisher Summary Most hydroxy-substituted azaheteroaromatic compounds exist predominately in the NH/carbonyl tautomeric form, and these compounds have been widely discussed. This chapter provides an overview of azaheteroaromatic compounds and I-azetin-4-ones—these are those azaheterocycles that contain in the ring at least one carbonyl group and one or two nitrogen atoms in the form of C=N or N=N bonds. Many of these compounds are unstable but their importance as reactive intermediates is established, and many of them could be used as synthons in the preparation of pharmacologically active compounds. The chapter describes the free existence of I-azetin-4-one and the nucleophilic substituti…
ÜBer die abhängigkeit des polymerisationsgrades und des substitutionsgrades von den nitrierbedingungen für cellulosenitrate verschiedener herkunft.
1961
Es wird der Einflus der Vorbehandlung, Nitriersaure, Nitrierdauer und Nitriertemperatur auf den Polymerisations- und Substitutionsgrad untersucht. Es wird dabei gezeigt, das die Nitrierung bei Wahl einer geeigneten Nitriersaure in allen Polymerisationsgradbereichen einschlieslich der hochstmolekularen nativen Cellulosen ohne Abbau verlauft, wenn man bei Temperaturen ≦ 0°C arbeitet. Weiterhin wurde festgestellt, das die Substitution durch ein Gleichgewicht bestimmt wird, so das der resultierende Substitutionsgrad im wesentlichen nur von der angewandten Nitriertemperatur abhangt. Bei Einhalten optimaler Nitrierbedingungen (geeignete Vorbehandlung und Nitriersaure) und gleicher Nitriertemperat…
Electrophilic substitution and cyclization of 2,2′-bis(N-methylindolyl): A simple access to potential protein kinase C inhibitor
1994
A strategy is described for the synthesis of functionalized and cyclized 2,2′-bisindolyl derivatives related to several basic systems of natural products. The starting 2,2′-bis(N-methylindolyl) (8) reacts with a variety of electrophiles and electrophilic dienophiles to furnish the novel, functionalized and cyclized bisindolyl derivatives 9–16. In addition, some reactivity and structural aspects are discussed; an X-ray crystallographic analysis of the 2,2′-bisindolyl 8 provided valuable information for the conformational analyses.
Crystal structure and reactivity of 2-chloro-3,5-dinitrothiophene and of 2-phenylsulphonyl-3,5-dinitrothiophene with nucleophiles
1988
The geometry obtained by a crystal structure determination of the title compounds, as compared with that of the analogous benzene derivatives, along with results of ab initio calculations, is used to interpret the different SNAr reactivities in some thiophene and benzene compounds. The smaller rotation of the nitro groups with respect to the aromatic rings observed in thiophene derivatives should be considered a relevant factor in the higher reactivity in the thiophene series.
Antidiabetische wirkstoffe. V Lang- und verzweigtkettig substituierte chlor-dihexylamino-1,3,5-triazine
1985
Die nucleophile Substitution eines Chloratoms in 2,4-Dichlor-6-dihexylamino-1,3,5-triazin (1) durch Amine (2a-c) fuhrt zu den Alkylamino-chlor-dihexylamino-1,3,5-triazinen 3a-c. Fur Strukturtyp 3 typische Signale in den 1H-NMR-Spektren sind das Triplett bei 0,9 ppm fur die endstandigen Methylgruppen und das Multiplett bei 3,3-3,65 ppm fur die den Stickstoffatomen benachbarten Methylengruppen. In Verbindungsklasse 3 finden sich Vertreter mit antidiabetischer, trichomonazider, antiviraler und anthelminthischer Wirksamkeit. The nucleophilic substitution of one chlorine atom in 2,4-dichloro-6-dihexylamino-1,3,5-triazine (1) by amines 2a-c leads to the alkylamino-chlorodihexylamino-1,3,5-triazin…
Effect of proteins, phytates, ascorbic acid and citric acid on dialysability of calcium, iron, zinc and copper in soy-based infant formulas.
2000
The possible effect of ascorbic acid, citric acid, proteins and phytate on dialysability of Ca, Fe, Zn and Cu in soy-based infant formulas is studied, taking dialysability as a measure of the amount of element available for absorption. Different dialysis percentages for similar element contents in different formulas are found. A regression analysis was applied between Ca, Zn, Cu and Fe dialysis percentages and soy-based formula components to estimate the possible influence of the latter on the dialysability of the elements. Significant correlations were found between citric acid contents and dialysability of Zn and Fe. No correlations were found between protein, ascorbic acid and phytic aci…
ChemInform Abstract: Thioetherification of Chloroheteroarenes: A Binuclear Catalyst Promotes Wide Scope and High Functional-Group Tolerance.
2015
The nucleophilic substitution of a variety of chloro- and bromohetarenes with arylthiols is optimized to use [PdCl(allyl)]2 in combination with a ferrocenyltetraphosphane as ligand.