heterocyclic aldehydes
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2022 ◽  
Vol 7 (1) ◽  
pp. 115-121
Katarína Kráľová ◽  
Renata Gašparová ◽  
Martin Moncman

A new series of carboxhydrazides 6-8 was synthesized under microwave irradiation by reaction of carboxhydrazide 1 with heterocyclic aldehydes 2-4 in the presence of p-toluenesulfonic acid in ethanol. N-Benzoylcarboxhydrazide 9 was prepared by reaction of 1 with benzoylchlorid 5 in THF at room temperature. The effects of 6-9 on inhibition of photosynthetic electron transport in spinach chloroplasts and chlorophyll content in the antialgal suspensions of Chlorella vulgaris were investigated.

2021 ◽  
Vol 9 (3) ◽  
Renáta Gašparová ◽  
Katarína Kotlebová ◽  
Margita Lácová

Reactions of 4-hydroxycoumarin 1 with heterocyclic aldehydes 2-4 led to bis-4-hydroxycoumarin derivatives 5-7 under microwave irradiation as well as under the classical heating. The subsequent reactions of products 5-7 are described. 4,4’-Epoxydicoumarins 8, 9 were prepared by the reaction of 5-7 in acetic acid / p-toluenesulfonic acid medium. Compound 10 was prepared by the reaction of 5 in acetic anhydride in the presence sodium acetate. Dioxocine-1,15-dione 11 was prepared by the reaction of 6 with dichloromethane in sodium hydroxide-toluene.

Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3656
Wojciech Kiciński ◽  
Sławomir Dyjak ◽  
Mateusz Gratzke

Three types of cross-linked porous organic polymers (either oxygen-, nitrogen-, or sulfur-doped) were carbonized under a chlorine atmosphere to obtain chars in the form of microporous heteroatom-doped carbons. The studied organic polymers constitute thermosetting resins obtained via sol-gel polycondensation of resorcinol and five-membered heterocyclic aldehydes (either furan, pyrrole, or thiophene). Carbonization under highly oxidative chlorine (concentrated and diluted Cl2 atmosphere) was compared with pyrolysis under an inert helium atmosphere. All pyrolyzed samples were additionally annealed under NH3. The influence of pyrolysis and additional annealing conditions on the carbon materials’ porosity and chemical composition was elucidated.

2021 ◽  
Vol 14 (1) ◽  
pp. 81-91
Krishnappa B. Badiger ◽  
Kantharaju Kamanna

This paper present a novel Knoevenagel reaction protocol for the condensation of aromatic/heteroaromatic aldehydes with malononitrile to give α, β–unsaturated benzylidene derivatives. The main focus of this work is to reveal the usability of agro-waste extracts as a catalyst in the Knoevenagel condensation. The present protocol proceeds efficiently for various substituted aromatic and heterocyclic aldehydes in the Knoevenagel reactions. In addition, the present method describes direct isolation of the formed products without using organic solvent extraction gave good yields product.

K. V. Aleksandrova ◽  
Ye. K. Mykhalchenko ◽  
O. S. Shkoda ◽  
D. A. Vasyliev

One of the most important tasks of our indigenous pharmaceutical science is the necessity for new medicines because existing drugs are characterized by various side effects, resistance, high toxicity, and so on. New bioactive molecule synthesis utilizes substances of natural origin as well as chemically modified ones. Thus, the researcher’s attention is mainly focused on 3-,7-,8-substituted derivatives of the natural heterocyclic xanthine system, which possess a wide range of pharmacological action. Synthesis of a novel of (3-benzyl-8-propylxanthin-7-yl)acetohydrazides with antimicrobial and diuretic activities described in the paper. The aim of this work is to develop efficient methods for synthesis of (3-benzyl-8-propylxanthin-7-yl)acetohydrazide derivatives, and to study their physical-chemical properties. Materials and methods. Two-hour boiling of propyl 2-(3-benzyl-8-propylxanthine-7-yl)acetate by excess hydrazine hydrate in propan-2-ol medium have yielded the key the key intermediate 2-(3-benzyl-8-propylxanthine-7-yl)acetohydrazide. Further transformation of the latter has led to formation of corresponding acetohydrazide derivatives achieved by the reaction with aliphatic, aromatic, heterocyclic aldehydes, and ketones. The structure and the relative configuration of the synthesized compounds were elucidated by analyzing their physical-chemical data. Results. The synthesis and optimization of reaction conditions of (3-benzyl-8-propylxanthin-7-yl)acetohydrazide derivatives were conducted. The identification of all synthesized compounds was aided by various physical-chemical methods (thin layer chromatography, elemental analysis, IR, and 1H NMR spectroscopy). Conclusions. As a result of synthetic research the preparative synthesis method of (3-benzyl-8-propylxanthin-7-yl)acetohydrazide derivatives possessing antimicrobic, and diuretic activities was developed.

Catalysts ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 287
Jianguo Liu ◽  
Mingyue Zhang ◽  
Longlong Ma

Dibenzylamine motifs are an important class of crucial organic compounds and are widely used in fine chemical and pharmaceutical industries. The development of the efficient, economical, and environmentally friendly synthesis of amines using transition metal-based heterogeneous catalysts remains both desirable and challenging. Herein, we prepared the covalent organic framework (COF)-supported heterogeneous reduced COF-supported Pd-based catalyst and used it for the one-pot reductive amination of aldehydes. There are both Pd metallic state and oxidated Pdσ+ in the catalysts. Furthermore, in the presence of the reduced COF-supported Pd-based catalyst, many aromatic, aliphatic, and heterocyclic aldehydes with various functional groups substituted were converted to their corresponding amines products in good to excellent selectivity (up to 91%) under mild reaction conditions (70 °C, 2 h, NH3, 20 bar H2). This work expands the covalent organic frameworks for the material family and its support catalyst, opening up new catalytic applications in the economical, practical, and effective synthesis of secondary amines.

Molecules ◽  
2021 ◽  
Vol 26 (3) ◽  
pp. 668
Wojciech Kiciński ◽  
Sławomir Dyjak

Nitrogen-doped and heteroatom multi-doped carbon materials are considered excellent metal-free catalysts, superior catalyst supports for transition metal particles and single metal atoms (single-atom catalysts), as well as efficient sorbents for gas- and liquid-phase substances. Acid-catalyzed sol–gel polycondensation of hydroxybenzenes with heterocyclic aldehydes yields cross-linked thermosetting resins in the form of porous organic polymers (i.e., organic gels). Depending on the utilized hydroxybenzene (e.g., phenol, resorcinol, phloroglucinol, etc.) and heterocyclic aldehyde variety of heteroatom-doped organic polymers can be produced. Upon pyrolysis, highly porous and heteroatom-doped carbons are obtained. Herein, polycondensation of phloroglucinol with imidazole-2-carboxaldehyde (and other, similar heterocyclic aldehydes with two heteroatoms in the aromatic ring) is utilized to obtain porous, N-doped organic and carbon gels with N-content of up to 16.5 and 12 wt.%, respectively. Utilization of a heterocyclic aldehyde with two different heteroatoms yields dually-doped carbon materials. Upon pyrolysis, the porous polymers yield ultramicroporous N-doped and N,S co-doped carbons with specific surface areas of up to 800 m2g−1. The influence of the initial composition of reactants and the pyrolysis temperature on the structure and chemical composition of the final doped organic and carbon materials is studied in detail.

2020 ◽  
Vol 17 ◽  
Afroz Aslam ◽  
Mehtab Parveen ◽  
Kushvendra Singh

Aim: To synthesize chromeno-pyrazolo[1,2-b]phthalazine-6,9,14(7H)-trione analogs with the help of silica-supported bismuth nitrate catalyst. Background: Nitrogen-containing heterocyclic compounds are widespread, and their applications to pharmaceuticals, agrochemicals, and functional materials are becoming more and more important. Pyrazoles are an important class of compounds for new drug development, as they are the core structure of numerous biologically active compounds, including blockbuster drugs such as celecoxib, viagra, pyrazofurine, and many others. Similarly, heterocycles containing a phthalazine moiety are of current interest due to their pharmacological and biological activities, for example, pyrazolo[1,2-b]phthalazinedione is described as an anti-inflammatory, analgesic, antihypoxic, and antipyretic agent. Objective: In continuation of our ongoing investigation for the construction of efficient and simple approaches for the preparation of heterogeneous catalysts herein we wish to disclose a highly efficient, simple, and one-pot synthesis of chromeno-pyrazolo-phthalazine derivatives via a one-pot multi-component reaction between 4-hydroxycoumarin, aromatic/heterocyclic aldehydes and 2,3-dihydro-1,4- phthalazinedione using silica-supported bismuth nitrate as an inexpensive, environmentally friendly and reusable catalysts under solvent-free conditions. Materials and Methods: Microanalytical data (C, H, and N) were collected on Carlo Erba analyzer model 1108. The microwave synthesis was performed in Anton Paar, Monowave 300 microwave synthesizer. Melting points were measured in open glass capillaries in the Kofler apparatus and may be uncorrected. Spectroscopic data were obtained using the following instruments: Fourier transform infrared spectra (KBr discs, 4000-400 cm-1 ) by Shimadzu IR-408 Perkin-Elmer 1800 instrument; 1H NMR and 13C NMR spectra by Bruker Avance-II 400 MHz using DMSO-d6 as a solvent containing TMS as the internal standard. Mass spectra were set down on a JEOL D-300 mass spectrometer. Results: To continue our ongoing studies to synthesize heterocyclic and pharmaceutical compounds by mild, facile, and efficient protocols, herein we wish to report our experimental results on the synthesis of chromeno-pyrazolo-phthalazine derivatives under solvent-free condition derivatives, using various aromatic/heterocyclic aldehydes in the presence of silica-supported bismuth nitrate catalyst. The prepared catalyst was characterized by various physical and chemical techniques. Conclusion: We have demonstrated an efficient reaction path for the synthesis of new aryl and heteroaryl chromeno-pyrazolo[1,2- b]phthalazine-6,9,14(7H)-trione by one-pot three-component condensation of aryl/heteroaryl aldehydes, 2,3-dihydro-1,4-phthalazinedione and 4-hydroxy coumarin using silica-supported bismuth nitrate (SSBN) under microwave irradiation. The scheme not only offers the use of microwave at low temperatures and significant yield of products but also affords mild reaction conditions, without harmful solvent, shorter reaction times, high purity, operational simplicity, and easy workup.

2020 ◽  
Manuela Raposo ◽  
Rui Sousa ◽  
Raquel Gonçalves ◽  
Susana Costa ◽  
Rita Figueira

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