- Formal ring-opening/cross-coupling reactions of 2-pyrones: Iron-catalyzed entry into stereodefined dienyl carboxylates
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Open access: Despite the exceptional level of sophistication in cross-coupling chemistry, reactions of substrates that incorporate the leaving group as an integral part into a heterocyclic scaffold are scarce. The title reaction outlines the utility of this reaction format (see scheme; acac=acetylacetonate), provides a convenient entry into stereodefined diene carboxylates, and adds a new chapter to the field of iron catalysis. Copyright
- Sun, Chang-Liang,Fuerstner, Alois
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supporting information
p. 13071 - 13075
(2014/01/06)
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- Antifungal activity of 4-methyl-6-alkyl-2H-pyran-2-ones
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A number of 4-methyl-6-alkyl-α-pyrones were synthesized and characterized on the basis of 1H NMR and mass spectroscopy. These compounds were tested in vitro against pathogenic fungi, namely, Sclerotium rolfsii Saccardo, Rhizoctonia bataticola (Taub.) Butler, Pythium aphanidermatum (Edson) Fitz., Macrophomina phaseolina (Tassi), Pythium debaryanum (Hesse), and Rhizoctonia solani Nees. Lower homologues were less effective, whereas compounds such as 4-methyl-6-butyl-α-pyrone, 4-methyl-6-pentyl-α-pyrone, 4-methyl-6-hexyl-α-pyrone, and 4-methyl-6-heptyl-α-pyrone were found effective against all of the test fungi. They inhibited mycelial growth by approximately 50% (ED50) at 15-50 μg/mL. 4-Methyl-6-hexyl-α- pyrone, which was found most effective, was tested against S. rolfsii in a greenhouse at 1, 5, and 10% concentrations. The 10% aqueous emulsion of 4-methyl-6-hexyl-α-pyrone suppressed disease development in tomato by 90-93% as compared with the untreated infested soil in the greenhouse after 35 days of treatment.
- Chattapadhyay, Tarun Kumar,Dureja, Prem
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p. 2129 - 2133
(2007/10/03)
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- Derivatives of (AZA)naphthalenesultam, their preparation and compositions containing them
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This invention relates to a compound STR1 in which R 1 representsa 1,2,3,6-tetrahydro-1-pyridyl radical substituted in the 4-position by (a) a phenyl radical, (b) a phenyl radical substituted by a halogen atom or an alkyl, hydroxy or alkoxy radical, (c) a 3-indolyl radical, (d) a 3-indolyl radical substituted on the nitrogen atom by an alkyl or alkylcarbonyl radical and/or in the 5-position by a halogen atom or (e) a 3-(5-hydroxyindolyl) radical.a 1-piperazinyl radical substituted in the 4-position by (a) a phenyl radical, (b) a phenyl radical substituted by an alkoxy, alkyl, hydroxy, nitro or amino radical or a halogen atom, (c) a 1,2-benzisothiazol-3-yl radical, (d) a 1,2-benzisoxazol-3-yl radical or (e) a 2-pyridyl radical.a piperidino radical substituted in the 4-position by (a) a phenyl radical, (b) a phenyl radical substituted by a halogen atom or a hydroxy, alkyl or alkoxy radical, (c) two phenyl radicals, (d) a bis(4-fluorophenyl)methylene radical, (e) a 4-fluorobenzoyl radical, (f) a 2-oxo-1-benzimidazolinyl radical, (g) a 2-oxo-1-benzimidazolinyl radical substituted in the 3-position by an alkylcarbonyl or benzoyl radical, (b) a hydroxy radical and a phenyl radical optionally substituted with an alkyl, alkoxy or hydroxy radical or a halogen atom, (i) a 3-indolyl radical, (j) a 3-indolyl radical substituted on the nitrogen atom by an alkyl or alkylcarbonyl radical and/or in the 5-position by a halogen atom or (k) a 3-(5-hydroxyindolyl) radical.either:R 2 and R 3, which are identical, represent a hydrogen or halogen atom and R 4 represents a hydrogen atom orR 2 and R 4 represent a hydrogen atom and R 3 represents a halogen atom or an acetylamino radical orR 2 and R 3 represent a hydrogen atom and R 4 represents a halogen atom and R 5 represents a --CH group.or R 2, R 3 and R 4 represent a hydrogen atom and R 5 represents a nitrogen atom.R 6 represents an alkylene chain containing 2 to 4 carbon atoms or a propylene chain substituted in the 1- or 3-position by an alkyl radical or in the 2-position by an alkyl, alkoxy, hydroxy, dialkylamino, piperidino, morpholino or thiomorpholino radical,with the reservation that when R 6 represents a propylene radical substituted in the 2-position by a dialkylamino, piperidino, morpholino or thiomorpholino radical, R 1 cannot be a radical containing a hydroxy radical, and their salts, are useful in therapy for their ability to block serotonin receptors.
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- Activity of aromatic substituted phenylpiperazines lacking affinity for dopamine binding sites in a preclinical test of antipsychotic efficacy
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Generally, antipsychotic agents are dopamine receptor blocking agents that also block conditioned avoidance responding (CAR) in the rat. Recently, however, both (o-methoxyphenyl)piperazine (OMPP, 1h) and (m-chlorophenyl)piperazine (MCPP, 1o) have been reported to block conditioned avoidance responding in the rat although neither has dopamine receptor blocking properties. The present paper examines the behavioral and biochemical profile of a number of additional substituted phenylpiperazines. None of the phenylpiperazines tested demonstrated high affinity for either dopamine D-1 or D-2 receptor sites, yet many effective in blocking CAR. The results suggest that the phenylpiperazines may be effective antipsychotic agents without blocking dopamine receptors. Moreover, the active compounds did demonstrate activity in displacing ligand binding to serotonin receptors. Receptor binding profiles were determined for 5-HT-1A and 5-HT-1B binding sites as well as for 5-HT-2 sites. The data from this preclinical test suggest these phenylpiperazines might be effective antipsychotic agents acting via a nondopaminergic mechanism of action.
- Martin,Elgin Jr.,Mathiasen,Davis,Kesslick,Baldy,Shank,DiStefano,Fedde,Scott
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p. 1052 - 1056
(2007/10/02)
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- Formation and Reactivity of Hydroxy-substituted γ- and δ-Lactones
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Hydrolysis of the esters (Z)-6-8 with H2SO4 in acetone leads to a mixture of γ- (17-19) and δ-Lactones (13-15) in various ratios.From (Z)-9 the rearrangement product 20 is obtained.By reaction of (Z)-6-9 with Et2O-BF3 the δ-lactones 13-16 are formed only.The saturated esters 10-12 hydrolyze to give a γ/δ-lactone mixture 24-26/21-23.Changing to BF3, favors the rearrangement 10 -> 30. - The δ-lactones 13-16 are not dehydrated with POCl3 in pyridine but chlorinated to afford 31-34.On heating in pyridine 33 and 34 are dehydrochlorinated to give the α-pyrones 38 and 39.Dechlorination with zinc in acetic acid leads to β,γ-unsaturated δ-lactones (31,35 -> 44; 32 -> 45; 33 -> 46).The mixture of saturated γ/δ-lactones 21b/24a/24b yields with POCl3 the elimination products 50 and 51, while a 23/26a/26b mixture furnishes the unsaturated γ-lactones 53a, b, and 54 as well as the chlorinated δ-lactones 55.Hydrogenation (44 -> 56; 45 -> 57; 46 -> 58; 51-> 59; 53/54 -> 60) gives the saturated parent compounds.
- Bardili, Burkhart,Marschall-Weyerstahl, Helga,Weyerstahl, Peter
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p. 275 - 300
(2007/10/02)
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