Search results for "MIDI"

Pyrazolo[3,4‐d]pyrimidine Derivatives as COX‐2 Selective Inhibitors: Synthesis and Molecular Modelling Studies

2009

The pyrazolo[3,4-d]pyrimidine system shows a multitude of interesting pharmacological properties. Owing to the potential anti-inflammatory activity of 5-benzamido-pyrazolo[3,4-d]pyrimidin-4-one derivatives and considering the easy synthesis of this class of compounds, a set of new 5-benzamido-1H-pyrazolo[3,4-d]pyrimidin-4-ones has been prepared in 42-80% yields by reacting 5-aminopyrazole-4(N-benzoyl)carbohydrazide derivatives and the opportune triethylorthoesters. Compounds 8a, b, 10a-d, and 11a, b revealed a superior inhibitory profile against COX-2, when compared to that of reference standards NS398 and indomethacin. Molecular modelling studies confirmed the obtained biological results.

Herbizide, 1. Mitt. 2-(4-Nitroanilino)pyrimidine

1982

Aus der Kondensation von 4-Nitrophenylguanidin (1) mit den β-Diketonen 2a–h gehen die 2-(4-Nitroanilino)pyrimidine 3a–h hervor. Als Aminoheterocyclus steht Verbindungstyp 3 in enger struktureller Beziehung zu 5-Acetyl-2-amino-4-methylthiazol, das herbizide Wirkungen auszuuben vermag. Herbicides, I: 2-(4-Nitroanilino)pyrimidines Condensation of 4-nitrophenylguanidine (1) with the β-diketones 2a–h yields the 2-(4-nitroanilino)pyrimidines 3a–h. Compounds of type 3 are aminoheterocycles and as such are closely related to 5-acetyl-2-amino-4-methylthiazole which exhibits herbicidal activity.

Trichomonazide Wirkstoffe, 2. Mitt. Verzweigtkettig 4,6-disubstituierte 2-Cyanaminopyrimidine

1985

Aus der Umsetzung von Dicyandiamid (1) mit den β-Diketonen 2a–b gehen die 4,6-verzweigtkettig disubstituierten 2-Cyanaminopyrimidine 3a–b hervor. Fur Strukturtyp 3 last sich aus den spektroskopischen Daten, speziell aus den 1H- und 13C-NMR-Werten, das Vorliegen eines Gleichgewichts zwischen den tautomeren 2-Cyanamino- und 2-Cyaniminopyrimidinformen ableiten. 3 zeichnet sich durch trichomonazide, antivirale und antimykotische Wirkung aus. Trichomonacidal Agents, II: 4,6-Disubstituted 2-(Cyanoamino)pyrimidines Carrying Branched Substituents The reaction of dicyandiamide (1) with the β-diketones 2a–b yields the 4,6-branched disubstituted 2-(cyanoamino)pyrimidines 3a–b. From spectroscopic evide…

ChemInform Abstract: Pyrazolo[3,4-d][1,2,3]triazolo[1,5-a]pyrimidine: A New Ring System Through Dimroth Rearrangement.

2008

Abstract Derivatives of the new ring system pyrazolo[3,4- d ][1,2,3]triazolo[1,5- a ]pyrimidine were synthesized from the corresponding angular isomers, through a Dimroth rearrangement, in quantitative yields. Preliminary computational studies demonstrated that this class of compounds could be a good candidate as DNA intercalating agents.

Reactions of 4,7-dihydro-1,2,4-triazolo[1,5-a]pyrimidines with α,β-unsaturated carbonyl compounds

2004

The reaction of 5,7-diphenyl-4,7-dihydro-1,2,4-triazolo[1,5-a]pyrimidine (1) with α,β-unsaturated carbonyl compounds 2a-f led to the formation of the alkylated heterocycles 3a-f (Figure 1). However, the reaction of 5-methyl-7-phenyl-4,7-dihydro-1,2,4-triazolo[1,5-a]pyrimidine (5) with 2a-c yielded under the same conditions the triazolo[5,1-b]quinazolines 6a-c (Figure 3). In this case, the alkylation is followed by a cyclocondensation. The structure elucidation of the products is based on ir, ms, 1H and 13C nmr measurements and on an X-ray diffraction study.

ChemInform Abstract: Heterocyclic Rearrangements. Synthesis of 1,2,4-Oxadiazolo(2,3-a)pyrimidinium Systems and Their Ring Opening into Pyrimidine N-O…

1987

Reaction des methyl- et phenyl-5 amino-3 oxadiazoles-1,2,4 avec l'acetylacetone ou la benzoylacetone en presence d'acide perchlorique: obtention de methyl- et phenyl-2 methyl- et phenyl-5 methyl-7 oxadiazolo [2,3-a] pyrimidiniums-4 qui se decyclisent ensuite en oxydes-1 d'acylamino-2- et amino-2 methyl-4 methyl- et phenyl-6 pyrimidines

ChemInform Abstract: Synthesis of Pyrido(2,3-d)pyrimidines in the Reaction of 6-Amino-2,3- dihydro-2-thioxo-4(1H)-pyrimidinone with Chalcones.

2010

6-Amino-2,3-dihydro-2-thioxo-4(1H)-pyrimidinone (1) reacts in boiling DMF with α,/β-unsaturated ketones 2 yielding the pyrido[2,3-d]pyrimidine systems 5 and 6, respectively. The orientation in the addition process can be determined by nmr measurements, especially by NOE difference spectroscopy. The products do not correspond to a normal Skraup or Doebner-v. Miller synthesis.

New Tetracyclic Ring System of Biological Interest Indolo[3,2-e][1,2,3]triazolo[1,5-a]pyrimidine through domino reactions of 2-azidoindole

2003

H2-Antihistaminika, 18. Mitt. 5,6-Alkylsubstituierte 4-Pyrimidinone mit H2-antihistaminischer Wirkung

1984

5,6-Alkylsubstituierte 2-{2-[(5-Methyl-4-imidazolyl)-methylthio]-ethylamino}-4-pyrimidinone wurden dargestellt und auf ihre H2-antihistaminische Wirksamkeit untersucht. H2-Antihistaminics, XVIII: 5,6-Alkyl-4-pyrimidones with H2-Antihistaminic Activity 5,6-Alkyl-2-{2-[(5-methyl-4-imidazolyl)methylthio]ethylamino}-4- pyrimidones were prepared and tested for their H2-antihistaminic activities.

Chemoselective reactions of N1-methyl-2-hydroxy-3-methylamino-3-phenylpropanamide with electrophiles. Synthesis of chiral hexahydro-4-pyrimidinones a…

2002

Abstract The reactivity of (2S,3S)-N1-methyl-2-hydroxy-3-methylamino-3-phenylpropanamide 1 , containing three nucleophilic centres has been studied against dihaloalkanes and aldehydes. Hexahydro-4-pyrimidinones or oxazolidines were obtained chemoselectively. Experimental results were explained by ‘ab initio’ calculations.