Search results for "Ethylamine"

1982

p-Cresol and eight oligo[(hydroxyphenylene)methylene] compounds 1b–e and 4a–d could be esterified with good yields with acryloyl chloride or propionyl chloride, respectively, in the presence of triethylamine. The simple and multiple acrylates and propionates were characterized by determination of their molar masses, elemental analyses, hydrogenation of the CC double bonds in the acrylate groups, and by their IR- and UV-spectra. No steric hindrance could be ascertained. Acrylates with more than three phenolic units in their molecules were found to have a range of melting, whereas all the propionates possess sharp melting points. This can be explained by polymerization of the acrylates which …

ChemInform Abstract: Photoinduced Molecular Rearrangements. Some Comments on the Ring-Photoisomerization of 1,2,4-Oxadiazoles into 1,3,4-Oxadiazoles.

2010

The ring-photoisomerization of 3-amino- and 3-methylamino-5-phenyl-1,2,4-oxadiazoles into the corresponding 2-amino- and 2-methylamino-5-phenyl-1,3,4-oxadiazoles has been reinvestigated by examining the effect of a base on the photoreaction. On irradiating at λ = 254 nm in methanol, yields of the ring-photoisomers were found to be significantly enhanced by the addition of triethylamine (TEA) in the photoreaction medium. By contrast, irradiation of the 3-amino-5-phenyloxadiazole in acetonitrile containing TEA gave an almost complete photoreduction into benzoylguanidine, while few percent of the ring photoisomer were detected. Furthermore, the pyrene-sensitized photolysis of 3-amino-5-phenylo…

Synthese und13C-NMR-Spektroskopie cyclischer und acyclischer β-Phosphonioenamine

1979

Quartare Phosphoniumsalze, die auser einem Allyl- einen Alkinylrest (z. B. 1) oder einen Acylmethylrest tragen (z. B. 4–6) reagieren mit primaren Aminen zu den bisher unbekannten 1,2,3,4-Tetrahydro-1,4-azaphosphoriniumsalzen 2, 3, 8–12, 19 und 25. Die Umsetzung von 4 liefert in Abhangigkeit vom eingesetzten Amin auser 8–12 die 5-Amino-1,2,3,4-tetrahydro-3-methylphosphoriniumsalze 13–16 die im sauren Medium schnell zu 17 hydrolysieren. Als Zwischenstufen der Cyclisierung von 4 konnen die offenkettigen β-Phosphonioenamine 18, 20 und 21 isoliert werden. Die Cyclisierung von 18 zu 19 gelingt erst in Gegenwart von Triethylamin als Base. Struktur und Konfiguration der neuen Verbindungen werden mi…

ChemInform Abstract: Highly Enantioselective Copper(I)-Catalyzed Conjugate Addition of 1,3-Diynes to α,β-Unsaturated Trifluoromethyl Ketones.

2015

The conjugate diynylation of α,β-saturated trifluoromethyl ketones is carried out at low catalytic loading (2.5 mol% for aryl substituents) of a copper(I)—MeO-BIPHEP complex, triethylamine and a terminal 1,3-diyne.

Die herstellung molekulareinheitlicher leiteroligomerer und einer molekulareinheitlichen hexaacrylsäure. IV. Mitt.: Modelle für matrizenreaktionen

1968

Die phenolischen Hydroxylgruppen molekulareinheitlicher Mehrkernverbindungen mit vier und funf pKresolbausteinen je Molekul konnten vollstandig mit Acrylsaurechlorid in Gegenwart von Triathylamin verestert werden. Lies man auf die in siedendem Benzol stark verdunnten mehrafachen Acrylsaureester einen Uberschus an Radikalen aus α.α′-Azoisobutyrodinitril einwirken, so bildeten sich mit guter Ausbeute molekulareinheitliche, dunnschichtchromatographisch reine Leiteroligomere. Die alkalische Verseifung des Leiteroilgomeren mit vier p-Kresolbausteinen gab eine molekulareinheitliche Hexaacrylsaure, die als Hexamethylester durch Elementaranalyse und Molekulargewicht charakterisiert wurde; die gefun…

Rapid fluorimetric assay for primary amine groups in water samples

2003

Bond Elut C(18) solid-phase extraction cartridges were used for pre-concentration followed by derivatization with o-phthaldialdehyde-N-acetylcysteine (OPA-NAC) of primary amines in water. Optimal conditions were: conditioning the cartridges with borate buffer pH 10.4, retention of the primary amines, addition of the OPA-NAC(3.7 mmol L(-1)) 1:1 molar ratio and borate buffer pH 8, elution of the isoindol with MeOH-borate buffer (9:1) pH 10.2 and fluorescence measurement. The equations of the calibration graphs for methylamine, ethylamine, propylamine, butylamine, pentylamine, and beta-phenylethylamine at lambda(excitation)=330 nm and lambda(emission)=440 nm, in the optimal conditions are pres…

The structure of ammonium pyrazolates in the solid state

2006

The crystals obtained by mixing equimolar amounts of diethyl 1H-pyrazole-3,5-dicarboxylate and the primary amines phenethylamine and homoveratrylamine are ammonium pyrazolate salts as determined by 13C and 15N CPMAS NMR. Copyright © 2006 John Wiley & Sons, Ltd.

Competing Ring-Photoisomerization Pathways in the 1,2,4-Oxadiazole Series. An Unprecedented Ring-Degenerate Photoisomerization

2002

The irradiation of some 5-alkyl-3-amino-1,2,4-oxadiazoles at lambda = 254 nm in methanol in the presence of triethylamine (TEA) gave ring-photoisomerization both into 2-alkyl-5-amino-1,3,4-oxadiazoles and, unprecedently, into the ring-degenerate 3-alkyl-5-amino-1,2,4-oxadiazoles. The competing ring contraction-ring expansion route and the internal cyclization-isomerization mechanism explain the results.

Photoinduced Single Electron Transfer on 5-Aryl-1,2,4-oxadiazoles:  Some Mechanistic Investigations in the Synthesis of Quinazolin-4-ones

1999

The photochemistry of some 5-aryl-3-methoxy- (or 5-aryl-3-phenyl-) 1,2,4-oxadiazoles irradiated in the presence of different sensitizers [such as diphenylacetylene (DAC), 9,10-diphenylanthracene (DAN), or triphenylene (TPH)] or ground-state donors such as triethylamine (TEA) has been investigated. Intermediates arising from breaking of the ring O-N bond develop both into quinazolin-4-ones (by a heterocyclization reaction involving the aryl at the C-5 of the oxadiazole nucleus) and into open-chain products (corresponding to a reduction at the ring O-N bond), in different ratios depending on their structures and photoreaction conditions. A reasonable explanation considers sensitization by pho…

ChemInform Abstract: Photoinduced Single Electron Transfer on 5-Aryl-1,2,4-oxadiazoles: Some Mechanistic Investigations in the Synthesis of Quinazoli…

2010

The photochemistry of some 5-aryl-3-methoxy- (or 5-aryl-3-phenyl-) 1,2,4-oxadiazoles irradiated in the presence of different sensitizers [such as diphenylacetylene (DAC), 9,10-diphenylanthracene (DAN), or triphenylene (TPH)] or ground-state donors such as triethylamine (TEA) has been investigated. Intermediates arising from breaking of the ring O-N bond develop both into quinazolin-4-ones (by a heterocyclization reaction involving the aryl at the C-5 of the oxadiazole nucleus) and into open-chain products (corresponding to a reduction at the ring O-N bond), in different ratios depending on their structures and photoreaction conditions. A reasonable explanation considers sensitization by pho…