An efficient synthesis of polyhydroquinoline derivatives was reported via four-component coupling reactions of aldehydes, 1,3-dicarbonyl ketones (dimedone or 1,3-cyclohexanedione), ethyl acetoacetate or methyl acetoacetate and ammonium acetate in the presence of a catalytic amount of nanocrystalline TiO2 under solvent free conditions. The reported method is mild, rapid and has the advantages su...

The Acylase "Amano" (AA)-catalyzed synthesis of valuable pyridin-2-ones via domino Knoevenagel condensation-Michael addition-intramolecular cyclization-oxidization reaction between aldehyde, cyanoacetamide and ethyl acetoacetate or cyclohexyl acetoacetate was developed in the sense of a one-pot strategy. Various aliphatic, aromatic and hetero-aromatic pyridin-2-ones could also be produced in th...

the one-pot, multi-component synthesis of 4,4′-(arylmethylene)bis(1h-pyrazol-5-ols) by tandem knoevenagel-michael reaction of phenylhydrazine, ethyl acetoacetate and aldehydes in the presence of silica-bonded n-propylpiperazine sulfamic acid (sbppsa) as a recyclable solid acid catalyst was reported. sbppsa showed much the same efficiency when used in consecutive reaction runs.

Quinoxalin-2-one (1) reacts with ethyl acetoacetate in trifluoroacetic acid (TFA) to form 3-(2-oxopropylideno)-3,4-dihydroquinoxaline-2-one (2) and 3-(3-oxo-3,4- dihydroquinoxaline-2-(1H)-ylidene)methylquinoxaline-2-(1H)-one (3). The reaction product 3 was also obtained by heating the compound 1 acetone presence of TFA.

The title mol-ecule, C(19)H(23)NO(4), was synthesized by the reaction of benzaldehyde, ethyl acetoacetate and NH(4)HCO(3). The dihydro-pyridine ring adopts a flattened boat conformation and the plane of the base of the boat forms a dihedral angle of 88.78 (9)° with the phenyl ring. The packing is stabilized by strong inter-molecular N-H⋯O and weak inter-molecular C-H⋯O hydrogen bonds.

Copper perchlorate hexahydrate as an efficient catalyst was used for the synthesis of polyhydroquinolines by four-component condensation reaction of aldehyde, ethyl acetoacetate, dimedone, and ammonium acetate in excellent yields and short reaction times at room temperature under ultrasound irradiation. This novel synthetic method is especially favoured because it provides a synergy between cop...

Silica-ZnCl2 has been found to be an efficient and eco-friendly catalyst for the synthesis of substituted 4-methylcoumarins from ethyl acetoacetate and substituted phenols under "neat" conditions in an oil bath at 80°C. The experimental procedure is simple, includes shorter reaction times (15-65 min), compatible with sensitive functional groups, and results in excellent yield of the products.