Solvent-free synthesis of functionalized pyridine derivatives using Wells-Dawson heteropolyacid as catalyst

Sánchez, Laura M.; Sathicq, Ángel Gabriel; Jios, Jorge L.; Baronetti, Graciela T.; Thomas, Helen; Romanelli, Gustavo Pablo

doi:10.1016/j.tetlet.2011.06.048

Cited by 30 publications

(17 citation statements)

References 23 publications

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“…The starting material (methyl 3-aminocrotonate) was prepared using a literature procedure [13]. The reaction was performed in a round bottom flask, which was equipped with a condenser and immersed in an oil bath.…”

Section: Specific Procedures For the Synthesis Of Nitrendipinementioning

confidence: 99%

“…HPAs possess a very strong acidity, which can be changed by varying the chemical composition of the primary structure of the heteropolyanion. As part of a research project to develop eco-efficient organic transformation, especially multicomponent reactions, we used different bulk, supported and included heteropolyacids in the preparation of heterocyclic synthesis, under greener conditions, such as the synthesis of functionalized pyridine [13], substituted 3,4-dihydropyrimidin-2-(1H)-ones [14], 14-aryl-14H-dibenzo[a, j]xanthenes [15], highly substituted hexahydropyrimidines [16], and ferrocenyl-pyrimidones [17].…”

Section: Introductionmentioning

confidence: 99%

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First Report About the Use of Micellar Keggin Heteropolyacids as Catalysts in the Green Multicomponent Synthesis of Nifedipine Derivatives

et al. 2016

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Micellar Keggin heteropolyacid catalysts were prepared using hexadecyltrimethylammonium bromide (cetyltrimethylammonium bromide-CTAB), 1-hexadecylpyridinium chloride, and Keggin heteropolyacids H 3 PMo 12 O 40 and H 4 PMo 11 VO 40 as precursors. Four catalysts were prepared (PMo12C16, PMo11VC16, PMo12C 16Py, and PMo11VC16Py) and characterized by 31 P NMR, FT-IR, XRD, SEM analysis and textural properties (S BET ). The acidic characteristics of the catalysts were determined by potentiometric titration with n-butylamine. A series of bioactive 1,4-dihydropyridine derivatives such as nifedipine and nemadipine B were synthesized using these new materials, in a one-pot procedure in ethanol. This methodology requires a reaction time of 8 h, and a temperature of 78°C to obtain good to excellent yields of 1,4-dihydropyridine derivatives. The micellar Keggin catalysts are insoluble in polar media, which allows easy removal of the reaction products without affecting their catalytic activity. The leaching test showed that they have an excellent stability and can be used five times as heterogeneous catalysts without appreciable loss of the catalytic activity. Using the same material, unsymmetrical 1,4-dihydropyridines such as nitrendipine can be obtained through a sequence of steps in very good yield (78 %). Graphical Abstract

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Section: Specific Procedures For the Synthesis Of Nitrendipinementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

First Report About the Use of Micellar Keggin Heteropolyacids as Catalysts in the Green Multicomponent Synthesis of Nifedipine Derivatives

et al. 2016

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“…As a result, it was observed that 3‐formylchromones showed an alternative direction of the Hantzsch condensation reaction. A functionalized pyridine in the 2‐, 3‐, and 5‐positions was formed by opening the γ‐pyrone ring after nucleophilic attack and subsequent cyclodehydration . The tendency to opening of the pyrone ring is well known and was also observed in 3‐formylchromones and in substituted 3‐formylchromones when amines or C‐nucleophilic anilines were used as nucleophiles .…”

Section: Introductionmentioning

confidence: 99%

“…In previous work, we introduced the use of 3‐formylchromones as a starting aldehyde in the Hantzsch reaction, replacing the traditionally used benzaldehyde derivatives, in order to give a new perspective to this reaction . 3‐Formylchromones were selected due to several reasons: first, they represent a very reactive system owing to the presence of an unsaturated keto function, a conjugated second carbonyl group at C3 and, above all, a very reactive electrophilic center at C2; second, they possess reactivity toward nucleophiles, such as hydrazine, phenylhydrazine, amidines, and aminopyrazoles; and third, the derivatives of chromones are important natural products possessing a wide range of valuable physiological activities .…”

Section: Introductionmentioning

confidence: 99%

Simple and ecofriendly synthesis of dihydropyrimidinones (thiones), dihydropyridines, and pyridines using 3‐formylchromones as substrates assisted by a recyclable Preyssler heteropolyacid

Sánchez

Pasquale

Sathicq

et al. 2016

Heteroatom Chemistry

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Several dihydropyrimidinones/thiones, 1,4-dihydropyridines, and pyridine derivatives were prepared in very good yields and purity values. The corresponding reactions were carried out by employing a bulk Preyssler heteropolyacid H 14 [NaP 5 W 29 MoO 110 ] as an efficient and recyclable catalyst. The preparation of pyridine derivatives was carried out not through a usual procedure, i.e., the opening of the γ-pyrone ring of 3-formylchromone. In general, reactions took place in solventfree conditions at 80°C during short reaction times.

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“…Solvent free reactions attract most of the researcher to develop new protocols in synthetic organic process. 11,12 The first synthetic method for the synthesis of dihydropyrimidione-2(1H)ones was reported by Biginelli, that involves one-pot three component condensation of bezaldehyde, ethylacetoacetate and urea under strongly acidic condition. 13 However, this reaction usually required harsh reaction condition, long reaction time and afford low yield.…”

Section: Introductionmentioning

confidence: 99%

One-pot solvent free synthesis of dihydropyrimidinones using calcined Mg/Fe hydrotalcite catalyst

Dabholkar¹,

Badhe²,

Kurade³

2017

10.5267/j.ccl

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The Mg/Fe = 3 hydrotalcite as reusable solid catalyst was found to be an excellent heterogeneous base catalyst for the synthesis of 3,4-dihydropyrimidinones/thiones, a multicomponent reaction using substituted aromatic aldehyde, ethyl acetoacetate and urea/thiourea. The work has been carried out under thermal solvent free conditions. Mg/Fe = 3 hydrotalcite heterogeneous solid catalyst offers simple means of recovery and the isolated catalyst was reused for number of times without significant loss of catalytic activity.

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Solvent-free synthesis of functionalized pyridine derivatives using Wells-Dawson heteropolyacid as catalyst

Cited by 30 publications

References 23 publications

First Report About the Use of Micellar Keggin Heteropolyacids as Catalysts in the Green Multicomponent Synthesis of Nifedipine Derivatives

First Report About the Use of Micellar Keggin Heteropolyacids as Catalysts in the Green Multicomponent Synthesis of Nifedipine Derivatives

Simple and ecofriendly synthesis of dihydropyrimidinones (thiones), dihydropyridines, and pyridines using 3‐formylchromones as substrates assisted by a recyclable Preyssler heteropolyacid

One-pot solvent free synthesis of dihydropyrimidinones using calcined Mg/Fe hydrotalcite catalyst

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