Search results for "Potassium carbonate"
showing 8 items of 8 documents
Antivirale Wirkstoffe, 18. Mitt. 2-Aminothiazole durch Spaltung der S-S-Bindung des Disulfidodicarbamidins
1981
Bei der Umsetzung von Disulfidodicarbamidin (1) mit β-Diketonen 2 werden sowohl (2-Amino-5-thiazolyl)ketone 3 als auch 2,2′-Dithiobispyrimidine 4 und Pyrimidinthione 5 gebildet. Unter Verwendung von Ethanol/Kaliumcarbonat entstehen bei Raumtemp. sowohl aus aliphatisch symmetrisch (2a–c) als auch aus aliphatisch unsymmetrisch (2d) substsituierten, ferner aus fluorierten (2e) β-Diketonen, die korrespondierenden (2-Amino-5-thiazolyl)ketone 3a–e als Hauptprodukte. Antiviral Drugs, XVIII: 2-Aminothiazoles by Cleavage of the S-S-Bond of Disulfidodicarbamidine Through the interaction of disulfidodicarbamidine (1) with β-diketones 2, (2-amino-5-thiazolyl)ketones 3 as well as 2,2′-dithiobispyrimidin…
Polymere acroleine. III. Mittteilung. Oximierung und quantitative Bestimmung der Aldehydgruppen
1956
Die Oximierung von Disacryl wird beschrieben. Ferner werden Bedingungen fur eine quantitative Bestimmung von Aldehydgruppen in polymeren Acroleinen mitgeteilt. Es wird festgestellt, das Disacryl und ein durch Redox-Polymerisation gewonnenes Polyacrolein etwa 65% reaktionsfahige Aldehydgruppen enthalten. Bei Polyacroleinen, die mittels Borfluorid-Atherat oder Kaliumcarbonat gewonnen wurden, betragt der Umsatz mit Hydroxylamin nur etwa 20% d. Th. The oximation reaction of disacryl is described. The conditions of a quantitative determination of aldehyde function in polymeric acroleins have been investigated. It has been shown, that disacryl and an other polyacrolein, prepared by a redox-polyme…
On the reactivity of 3-bromo-2-nitrobenzo[ b ]thiophene with nucleophiles: elucidation of the base-catalysed mechanism with rearrangement
2001
Abstract The reactivity of 3-bromo-2-nitrobenzo[b]thiophene (1) with several (anionic and neutral) nucleophiles has been examined. Only with neutral, weak nucleophiles (as anilines) 1 gives, in the presence of non-nucleophilic bases (triethylamine or potassium carbonate), together with the ‘expected’ 3-amino-2-nitrobenzo[b]thiophenes (3) also the ‘unexpected’ 2-amino-3-nitrobenzo[b]thiophenes (4). The composition of the final isomeric mixture depends on the base added (nature and quantity) and on the solvent used. The results demonstrate the relevance of base-catalysis and support a reaction pathway involving the formation of an anionic intermediate (B) which undergoes addition of a second …
Preparation and characterization of new low melting ammonium-based ionic liquids with ether functionality
2009
Abstract Eighteen new and three previously known but insufficiently characterized RR´3N+A− and R2R´2N+A− type (R = 2-ethoxyethyl or 4-methoxybenzyl, R´ = methyl, ethyl, n-propyl, n-butyl, n-pentyl or n-hexyl, A = Br, BF4 or PF6) quaternary ammonium (QA) salts were synthesized and characterized by using 1H and 13C NMR techniques, mass spectroscopy and elemental analysis. The bromide salts were synthesized either by treating dimethyl formamide with an ether functionalized alkyl bromide in the presence of potassium carbonate or by treating a tertiary amine with an ether functionalized alkyl bromide. The QA tetrafluoroborates and hexafluorophosphates were synthesized by metathesis reaction betw…
Hydrolysis of DCNP (a Tabun mimic) catalyzed by mesoporous silica nanoparticles
2015
[EN] The hydrolysis of diethylcyanophosphonate, DCNP (a Tabun simulant) in the presence of mesoporous silica nanoparticles (MSN) has been studied in acetonitrile:water (99.5:0.5 v/v) mixtures using 31P NMR as a suitable technique to follow the DCNP hydrolysis. MSN alone was not capable to induce DCNP hydrolysis, yet MSN in combination with the presence of the bases potassium carbonate, triethylamine or DABCO enhanced DCNP degradation. When MSN was used combined with K2CO3, a hydrolysis of ca. 95% of the initial DCNP after 60 min was observed. In the presence of DABCO, MSN was able to induce the hydrolysis of ca. 90% of DCNP after the same time. However, the DCNP hydrolysis using MSN in the …
On the reaction of 3-bromo-2-nitrobenzo[b]thiophene with some ortho-substituted anilines: an analysis of the products of reaction and of their NMR an…
2003
Abstract The title reaction, carried out in DMF in the presence of triethylamine or potassium carbonate, has furnished the ‘expected’ 3-amino-2-nitrobenzo[ b ]thiophenes 2 o together with the ‘unexpected’ 2-amino-3-nitrobenzo[ b ]thiophenes 3 o , thus recalling the situation observed with other weak nucleophiles in the presence of non-nucleophilic bases. The effects (electronic as well as steric) of the ortho -substituent (OH, NH 2 , OMe, Me, Et, F, Cl and Br) on the course of the reaction have been investigated, determining their influence on yields and product ratios ( 2 o / 3 o ). An analysis of 13 C NMR and MS spectra of 2 o and 3 o has been carried out. Ab initio computations on 2 o f …
Antivirale Wirkstoffe, 20. Mitt. 4,6-Dialkylierte 2-Benzylthiopyrimidine
1981
Aus der Kondensation von Benzylisothioharnstoff (1) mit den β-Diketonen 2a–c gehen die 2-Benzylthiopyrimidine 3a–c hervor. Wird die Reaktion 1+2b jedoch in 30proz. wasr. Kaliumcarbonat-Losung/Ethanol/Ether durchgefuhrt, so tritt unter Ethanolyse Bildung von 2-Ethoxy-4,6-diethylpyrimidin (4) ein. 2-Benzylthio-4-ethyl-6-(trifluormethyl)pyrimidin ubt Hemmwirkung gegen Influenza A-Virus aus. Antiviral Agents, XX: 4,6-Dialkylated 2-Benzylthiopyrimidines Condensations of benzylisothiourea (1) with the β-diketones 2a–c yield the 4,6-dialkylated 2-benzylthiopyrimidines 3a–c. However, in 30% aqueous potassium carbonate solution/ethanol/ether, the reaction 1+2b proceeds by ethanolysis to form 2-ethox…
CCDC 1408384: Experimental Crystal Structure Determination
2015
Related Article: Toni Mäkelä, Elina Kalenius, and Kari Rissanen|2015|Inorg.Chem.|54|9154|doi:10.1021/acs.inorgchem.5b01577