Novel copolymers of vinyl acetate. 4. Halogen ring-substituted ethyl 2-cyano-3-phenyl-2-propenoates

Novel copolymers of vinyl acetate and halogen ring-substituted ethyl 2-cyano-3-phenyl-2-propenoates, RPhCH=C(CN)CO2C2H5 (where R is 2-Br, 3-Br, 4-Br, 2-Cl, 3-Cl, 4-Cl, 2-F, 3-F, 4-F, 2,3-dichloro, 2,4-dichloro, 2,6-dichloro, 3,4-dichloro, 2,4-difluoro, 2-bromo-3,4-dimethoxy) were prepared in solution with radical initiation at 70C. The propenoates were synthesized by the piperidine catalyzed Knoevenagel condensation of halogen ring-substituted benzaldehydes and ethyl cyanoacetate, and characterized by CHN analysis, IR, 1H and 13C-NMR. The compositions of the copolymers were calculated from nitrogen analysis and the structures were analyzed by IR, 1H and 13C-NMR. Thermal behavior of the copolymers was studied by DSC (Tg) and TGA. Decomposition of the copolymers in nitrogen occurred in two steps, first in the 159-500ºC range with residue (8.8-15.2 wt%), which then decomposed in the 500-650ºC range.

Novel copolymers of vinyl acetate. 3 Ring-substituted ethyl 2-cyano-3-phenyl-2-propenoates

Novel copolymers of vinyl acetate and ring-substituted ethyl 2-cyano-3-phenyl-2-propenoates, RPhCH=C(CN)CO2C2H5 (where R is 4-acetoxy, 4-acetamido, 2-cyano, 3-cyano, 4-cyano, 4-dimethylamino, 4-diethylamino, 2,4,6-trimethyl, 2,3-dimethyl-4-methoxy, 2,4-dimethoxy-3-methyl were prepared in solution with radical initiation at 70C. The propenoates were synthesized by the piperidine catalyzed Knoevenagel condensation of ring-substituted benzaldehydes and ethyl cyanoacetate, and characterized by CHN analysis, IR, 1H and 13C-NMR. The compositions of the copolymers were calculated from nitrogen analysis and the structures were analyzed by IR, 1H and 13C-NMR. Thermal behavior of the copolymers was studied by DSC (Tg) and TGA. Decomposition of the copolymers in nitrogen occurred in two steps, first in the 160-350ºC range with residue (1.5-15.1 wt%), which then decomposed in the 500-650ºC range.

Eco-friendly Synthesis of Some New Benzylidene-iminothiazolyl-pyrazol-3-ol Derivatives via One-Pot Multicomponent Reaction and Evaluation of Antioxidant Activities

In present work, one-pot multicomponent reaction (MCR) route for the synthesis of benzylideneiminothiazolyl- pyrazol-3-ol derivatives (5a-p) by reacting ethyl cyanoacetate (1), substituted benzaldehyde (2a-c), thiosemicarbazide (3) and substituted phenacyl bromide (4a-g). This reaction proceeds by using bleaching earth clay (BEC) (pH 12.5) in PEG-400 as a green reaction media. All the synthesized compounds were characterized by IR, 1H NMR, 13C NMR and mass spectral data. The pharmacological investigation of the synthesized compounds suggest that most of them showed good antioxidant activity.

Novel copolymers of vinyl acetate. 2. Oxy ring-substituted ethyl 2-cyano-3-phenyl-2-propenoates

Novel copolymers of vinyl acetate and oxy ring-substituted ethyl 2-cyano-3-phenyl-2-propenoates, RPhCH=C(CN)CO2C2H5 (where R is 2-methoxy, 3-methoxy, 4-methoxy, 2-ethoxy, 4-ethoxy, 4-propoxy, 4-butoxy, 2,3-dimethoxy, 2,4-dimethoxy, 2,5-dimethoxy, 3,4-dimethoxy, 2,3,4-trimethoxy, 2,4,5-trimethoxy, 2,4,6-trimethoxy, 3,4,5-trimethoxy) were prepared in solution with radical initiation at 70C. The propenoates were synthesized by the piperidine catalyzed Knoevenagel condensation of ring-substituted benzaldehydes and ethyl cyanoacetate, and characterized by CHN analysis, IR, 1H and 13C-NMR. The compositions of the copolymers were calculated from nitrogen analysis and the structures were analyzed by IR, 1H and 13C-NMR. Thermal behavior of the copolymers was studied by DSC (Tg) and TGA. Decomposition of the copolymers in nitrogen occurred in two steps, first in the 160-350ºC range with residue (2.2-25.3 wt%), which then decomposed in the 500-650ºC range.

Agro-waste sourced catalyst as an eco-friendly and sustainable approach for Knoevenagel condensation reaction

Background: The present work describes an eco-friendly and sustainable approach for the Knoevenagel condensation of an aromatic aldehyde with ethyl cyanoacetate, and salicylaldehyde with Meldrum acid for the synthesis of ethyl benzylidenecyanoacetate and 3-carboxy coumarin (2-oxo-2H-1-benzopyran) derivatives, respectively. The reaction performed under greener catalytic media Water Extract of Watermelon Fruit Peel Ash (WEWFPA) is an eco-friendly protocol derived from the agro-waste feedstock. Various protocols have been reported for the synthesis of Knoevenagel condensation reaction using a hazardous catalyst or/and solvent found toxic to the environment, reaction time longer, poor yield, and required purification of the final product. The present method provides several added advantages of being completely greener, economic, giving high yield, inexpensive catalyst, and the final product isolated in pure form with good yield. Objective: The objective of the study was to develop a green methodology for the synthesis of ethyl benzylidenecyanoacetate and 3-carboxy coumarin derivatives. Results: The agro-waste based catalyst developed avoids the use of external inorganic/organic base, additives, and solvent-free synthesis of Knoevenagel condensation of ethyl benzylidenecyanoacetate and 3-carboxy coumarin derivatives under rt and microwave irradiation, respectively described. The microwave irradiation condition requires less time for the completion of the reaction and also gave better yield isolation Methods: We have demonstrated WEWFPA as a greener homogenous agro-waste is employed under rt stirring and microwave irradiation for the economic synthesis of ethyl benzylidenecyanoacetate and 3-carboxy coumarin derivatives. The developed method was found robust, non-hazardous and solvent-free with simple work-up gave target product. Conclusion: In conclusion, we have established an efficient, simple, agro-waste based catalytic approach for the synthesis of ethylbenzylidenecyanoacetate and 3-carboxy coumarin derivatives employing WEWFPA as an efficient catalyst under rt stirring and microwave synthesis, respectively. The method is a greener, economical and eco-friendly approach for the synthesis of Knoevenagel condensation products. The advantages of the present approach are solvent-free, no external metal, chemical base free, short reaction time and isolated product in good to excellent yields. The catalyst is agro-waste derived, which has abundant in natural sources, thus making the present approach a greener one.

Synthesis of S-glycosides analogues containing Thiouracil unite and Evaluated as antibacterial and Antifungal active

Preparation of new S-glycosides including thiouracil derivatives as heterobase. The main step of this work is the formation of thiouracil derivatives [1-3] by the condensation reaction of ethyl cyanoacetate, aromatic aldehydes and thiourea to form target compounds [1-3], after protection of the hydroxyl groups in sugar (D-fructose, L- sorbose, and D-galactose), react with hydrobromic acid 45% in glacial acetic acid give different Bromo sugars [a-c], which coupled with prepares thiouracil derivatives [1-3] and propylthiouracil [4] in the presence of K2CO3 to afford the corresponding product S-glycoside analogs [1-4a, 1-4b, 1-4c]. deprotection of the S-glycoside analogs in acid and base medium, led to the free S-glycoside derivatives [1-4d,1-4e,1-4f]. The obtained compounds were tested for their antibacterial and antifungal actives.

Post-Synthetic Modification of UiO66 and its Application in Catalytic Reactions

Because of their unique surface area and adjustable pore size, Metal-Organic Frameworks(MOFs) have been widely used in lots of research fields, such as catalysis, energy storage, sensing, separation. In this paper, as for the Knoevenagel reaction, UiO66 and other UiO series MOFs were synthesized and modified. UiO66 nanoparticles were prepared by one-pot method. 2-aminopyridine, 3-aminopyridine and 4-aminopyridine were used to prepare UiO66-2Py, UiO66-3Py and UiO66-4Py nanoparticles. UiO66-2Py, UiO66-3Py and UiO66-4Py nanoparticles were modified by activated arginine, lysine and glycine to synthesize UiO66-2Py-Arg, UiO66-3Py-Lys and UiO66-4Py-Gly. Finally, the obtained samples were used for the Knoevenagel catalytic condensation reactions of benzaldehyde and ethyl cyanoacetate. In this process, the prepared samples and their intermediates were characterized by infrared spectroscopy (IR) and X-ray diffraction(XRD), which showed that the modification of UiO66 was successful. UiO66-3Py-Lys and UiO66-4Py-Gly showed high catalytic activity in the supernatant determined by fluorescence spectrophotometer, and UiO66-4Py-Gly showed the best catalytic effects at the volume of 0.4mL benzaldehyde.

Layer-Like Zeolite X as Catalyst in a Knoevenagel Condensation: The Effect of Different Preparation Pathways and Cation Exchange

This study is dedicated to the comparative investigation of the catalytic activity of layer-like Faujasite-type (FAU) zeolite X obtained from three different synthesis routes (additive-free route, Li2CO3 route, and TPOAC route) in a liquid-phase Knoevenagel condensation of benzaldehyde and ethyl cyanoacetate to ethyl trans-α-cyanocinnamate. It is shown that the charge-balancing cations (Na+ and K+) and the morphological properties have a strong influence on the apparent reaction rate and degree of conversion. The highest initial reaction rate could be found for the layer-like zeolite X synthesised by the additive-free route in the potassium form. In most cases, the potassium-exchanged zeolites enabled higher maximum conversions and higher reaction rates compared to the zeolite X catalysts in sodium form. However, very thin crystal plates (below 100 nm thickness), similar to those obtained in the presence of TPOAC, did not withstand the multiple aqueous ion exchange procedure, with the remaining coarse crystals facilitating less enhancement of the catalytic activity.