- Iron(III) chloride-catalyzed convenient one-pot synthesis of β-acetamido carbonyl compounds
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A one-pot multi-component reaction of aldehydes, enolizable ketones or 1,3-dicarbonyls, acetonitrile/benzonitrile, and acetyl chloride is described for the preparation of β-acetamido carbonyl compounds using FeCl3·6H2O as a mild, inexpensive, and highly efficient catalyst. The effect of substrate as well as substituent for multi-component reaction versus Knoevenagel condensation is also illustrated. The key features of this methodology are operational simplicity, mild reaction conditions, and good yields.
- Khan, Abu T.,Parvin, Tasneem,Choudhury, Lokman H.
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p. 5593 - 5601
(2007/12/25)
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- Process to prepare 1,4-dihydropyridine intermediates and derivatives thereof
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An improved catalyst is disclosed for a process involving the preparation of benzylidene intermediates useful in the preparation of 1,4-dihydropyridine compounds and derivatives thereof useful as medicines such as for example felodipine. This is accomplished by the condensation of an aldehyde and an acetoacetate in the presence of a novel catalyst system that includes a pyridyl carboxylic acid and a secondary amine. It has been found that through the use of the present invention the purity and yield of the desired isomer of the benzylidene intermediate can be maximized, thus avoiding the requirement of additional purification steps. The use of these intermediates can then be further reacted to form the required dihydropyridines, again having a very high purity and yield compared with the prior art.
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- Calcium entry blockers and activators: Conformational and structural determinants of dihydropyrimidine calcium channel modulators
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Dihydropyrimidines 4, 6, and 15, uniquely designed to unambiguously establish structural and conformational determinants for DHP receptor occupation and for modulation of calcium channel function, were prepared and examined for calcium channel modulation.
- Rovnyak,Kimball,Beyer,Cucinotta,DiMarco,Gougoutas,Hedberg,Malley,McCarthy,Zhang,Moreland
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p. 119 - 129
(2007/10/02)
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- Synthesis of 1,4-dihydro-2,6-dimethyl-4-(substituted phenyl)-5-N-methylaminocarbonyl-pyridine-3-carboxylate
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Michael addition of β-amino-N-methylcrotonamide to aralkylideneacetoacetic acid ester is followed by ring closer to give novel 4-aryl-1,4-dihydro-2,6-dimethyl-5-N-methylaminocarbonylpyridine-3-carboxylates (5).
- Sainani, J. B.,Shah, A. C.,Arya, V. P.
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p. 573 - 575
(2007/10/03)
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- Asymmetrical ester derivatives of 1,4-dihydrophyridine-3,5-dicarboxylic acid
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The present invention relates to novel asymmetrical esters derived from 1,4-dihydrophyridine-3,5-dicarboxylic acid, of the formula: STR1 in which: R1 represents a C1 -C4 alkyl group, R2 represents a C1 -C4 alkyl group, a benzyl group, a benzoyl group or a phenyl group optionally substituted by one or more C1 -C4 alkoxy, C1 -C4 alkyl, cyano, nitro, hydroxyl or trifluoromethyl groups or by one or more halogen atoms, and R3 and R4, which are identical or different, each represent the hydrogen atom, a nitro group or a chlorine atom, their optical isomers and diastereoisomers and also the corresponding addition salts. These novel esters are useful in therapy, especially as antihypertensives.
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