Preparation and Reactions of Trichloromethyl-Substituted Pyridine and Pyrimidine Derivatives

Synthesis ◽  
2018 ◽  
Vol 50 (20) ◽  
pp. 4071-4080 ◽  
Author(s):  
Reinhold Zimmer ◽  
Hans-Ulrich Reissig ◽  
Lina Unger ◽  
Matteo Accorsi ◽  
Christian Eidamshaus ◽  
...  
Keyword(s):  
Acetic Anhydride ◽  
Good Yield ◽  
Trichloroacetic Acid ◽  
Pyridine Derivative ◽  
Pyrimidine Derivatives ◽  
Methyl Group ◽  
Alternative Approach ◽  
Three Component Reaction ◽  
Trichloromethyl Group ◽  
Pyridine And Pyrimidine Derivatives

The three-component reaction of lithiated methoxyallene, nitriles and trichloroacetic acid gave three model β-keto enamides that were starting materials for the synthesis of trichloromethyl-substituted pyridine and pyrimidine N-oxide derivatives. Upon treatment with acetic anhydride, the methyl group of the prepared pyrimidine N-oxides was converted into an acetoxymethyl group by a Boekelheide rearrangement. A few typical experiments also revealed that the trichloromethyl group of the prepared pyrimidine N-oxides can be replaced by an alkoxy or a hydroxy group, or transformed into an arylthiomethyl group. An alternative approach to β-keto enamides via the corresponding β-keto enamines was also examined and provided the expected 4-hydroxy-6-(trichloromethyl)pyridine derivative in good yield.

scholarly journals The Flögel-three-component reaction with dicarboxylic acids – an approach to bis(β-alkoxy-β-ketoenamides) for the synthesis of complex pyridine and pyrimidine derivatives

2014 ◽  
Vol 10 ◽  
pp. 394-404 ◽  
Author(s):  
Mrinal K Bera ◽  
Moisés Domínguez ◽  
Paul Hommes ◽  
Hans-Ulrich Reissig
Keyword(s):  
Dft Calculations ◽  
Carboxylic Acids ◽  
Aromatic Compounds ◽  
Dicarboxylic Acids ◽  
Membered Ring ◽  
Simple Synthesis ◽  
Pyrimidine Derivatives ◽  
Three Component Reaction ◽  
Palladium Catalyzed ◽  
Pyridine And Pyrimidine Derivatives

An extension of the substrate scope of the Flögel-three-component reaction of lithiated alkoxyallenes, nitriles and carboxylic acids is presented. The use of dicarboxylic acids allowed the preparation of symmetrical bis(β-ketoenamides) from simple starting materials in moderate yields. Cyclocondensations of these enamides to 4-hydroxypyridine derivatives or to functionalized pyrimidines efficiently provided symmetrically and unsymmetrically substituted fairly complex (hetero)aromatic compounds containing up to six conjugated aryl and hetaryl groups. In addition, subsequent functionalizations of the obtained heterocycles by palladium-catalyzed couplings or by oxidations are reported. We also describe the simple synthesis of a structurally interesting macrocyclic bispyrimidine derivative incorporating a 17-membered ring, whose configuration was elucidated by DFT calculations and by subsequent reactions.

scholarly journals A Proline and 4‐Hydroxyproline Based Approach to Enantiopure Pyrrolidin‐2‐yl‐Substituted Pyridine and Pyrimidine Derivatives

2021 ◽  
Author(s):  
Benjamin Brennecke ◽  
Alicia Castelló Micó ◽  
Lars Selter ◽  
Matteo Accorsi ◽  
Reinhold Zimmer ◽  
...  
Keyword(s):  
Pyrimidine Derivatives ◽  
Pyridine And Pyrimidine Derivatives

Chemistry of Fenchonesulfonic Acid Derivatives

1995 ◽  
Vol 50 (2) ◽  
pp. 283-288 ◽  
Author(s):  
Gabriele Wagner ◽  
Uwe Verfürth ◽  
Rudolf Herrmann
Keyword(s):  
Acetic Anhydride ◽  
Thionyl Chloride ◽  
Sulfonic Acid ◽  
Reaction Rate ◽  
Enantiomeric Excess ◽  
Methyl Group ◽  
Close Analogy ◽  
Chiral Sulfoxides ◽  
Mndo Calculations ◽  
Nmr Techniques

(1 S) - (+)-Fenchone is sulfonated by SO3 or H2SO4/acetic anhydride in the bridgehead methyl group. This could be confirmed by NMR techniques (INADEQUATE). The fenchonesulfonic acid obtained is converted (SOCl2/NH3) to the cyclic fenchonesulfonimide, which can be oxidized to the corresponding oxaziridine, in close analogy to 10-camphorsulfonimide. Improved procedures for this reaction sequences are given. During the treatment of the sulfonic acid with thionyl chloride, a byproduct with a rearranged bicyclic skeleton is observed whose structure has been determined by ozonolytic degradation and NMR techniques. A possible mechanism for this rearrangement is suggested, based on MNDO calculations of the intermediate carbocations. The fenchonesulfonyloxaziridine oxidizes sulfides to chiral sulfoxides with appreciable enantiomeric excess, but very low reaction rate. A comparison with camphor-derived oxaziridines having similar steric requirements is made.

Synthesis of Some Pyrazolo [Diazepine, Pyrazole, Isoxazole and Pyrimidine] Derivatives and Related Compounds

1980 ◽  
Vol 35 (10) ◽  
pp. 1313-1316 ◽  
Author(s):  
El-Sayed Afsah ◽  
Fathy A. Amer ◽  
Momdouh Soafan
Keyword(s):  
Acetic Anhydride ◽  
Acid Derivative ◽  
Pyrimidine Derivatives ◽  
Related Compounds

Abstract 4-Arylidene-3-methyl-1-phenyl-2-pyrazolin-5-ones (1a-d) undergoes condensation with diethylmalonate, p-nitroacetophenone and/or 3-acetyl-pyridine under Michael condition to give compounds 2, 3 and 4, respectively. Treatment of 3 and 4 with hydrazine afforded the pyrazolodiazepines 7 and 8, respectively. Interaction of la with diethyl phenyl-malonate gave the Michael product 9, which undergoes hydrolysis, decarboxylation and cyclisation to give the indanone derivative (11). Condensation of 1c with hydrazine, hydroxylamine and urea gives compounds 12, 13 and 14, respectively. Cyclisation of the Michael compound 15 gives the benzopyranopyrazole (14). When 1c was subjected to Riemer-Tiemann reaction gives compounds 17 and 18. Acetic anhydride treatment of 18 gives the acetyl cresotic acid derivative (19).

PTSA-Catalyzed One Pot Domino Synthesis of Dihydropyrido[2,3-d]pyrimidine Derivatives and their Antimicrobial Activity

2021 ◽  
Vol 6 (3) ◽  
pp. 222-227
Author(s):  
Krishna A. Bhensdadia ◽  
Prakash L. Kalavadiya ◽  
Nilam H. Lalavani ◽  
Shipra H. Baluja
Keyword(s):  
Antimicrobial Activity ◽  
Spectral Analysis ◽  
Pyrimidine Derivatives ◽  
One Pot ◽  
In Vitro Antimicrobial Activity ◽  
Aryl Aldehydes ◽  
Three Component Reaction ◽  
The One

A novel series of dihydropyrido[2,3-d]pyrimidine derivatives were synthesized by multicomponent domino cyclization via the one-pot three component reaction of 6-amino uracil, substituted aryl aldehydes and N-methyl-1-(methylthio)-2-nitroethenamine in the presence of PTSA 10 mol% as a catalyst. The structures of these synthesized compounds were characterized by spectral analysis. Further the synthesized compounds screened for in vitro antimicrobial activity. Among all the compounds, compound 4b containing flouro substitution exhibited good inhibition against the tested species.

scholarly journals Trichloressigsäure-Aceton-Extraktion von Albuminen aus Seren und Antigen-Antikörper-Präzipitaten

1957 ◽  
Vol 12 (12) ◽  
pp. 777-783 ◽  
Author(s):  
Ekkehard Kallee ◽  
Friedrich Lohss ◽  
Willmar Oppermann
Keyword(s):  
Good Yield ◽  
Trichloroacetic Acid ◽  
Human Albumin ◽  
Binding Ability ◽  
Dye Binding

1. Highly purified albumin fractions can be obtained by precipitating human, rabbit, or rat sera with trichloroacetic acid, and extracting the precipitates with acetone.2. Human albumin thus prepared is identical with the original albumin in its electrophoretic properties, its dye-binding ability, and in its immunological behavior.3. After precipitating human albumin with antibodies the albumin antigen can be extracted in a good yield by use of trichloroacetic acid and acetone without losing the electrophoretic or antigenic characteristics of albumin.

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