Reaction of d-sabinol with selenium dioxide. III. Structure of the main product

1960 ◽  
Vol 25 (2) ◽  
pp. 604-607 ◽  
Author(s):  
J. Kovář ◽  
F. Petrů
Keyword(s):  
Main Product ◽  
Selenium Dioxide

Substituted 4-Formyl-2H-chromen-2-ones: Their Reaction with N-(2,3,4,6-Tetra-Oacetyl- β-D-galactopyranosyl)thiosemicarbazide, Antibacterial and Antifungal Activity of Their Thiosemicarbazone Products

2020 ◽  
Vol 24 (19) ◽  
pp. 2272-2282
Author(s):  
Vu Ngoc Toan ◽  
Nguyen Minh Tri ◽  
Nguyen Dinh Thanh
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Candida Albicans ◽  
Selenium Dioxide ◽  
Antibacterial And Antifungal Activity ◽  
E Coli ◽  
Antibacterial And Antifungal Activities ◽  
Alkyl Ethers ◽  
Antibacterial And Antifungal

Several 6- and 7-alkoxy-2-oxo-2H-chromene-4-carbaldehydes were prepared from corresponding alkyl ethers of 6- and 7-hydroxy-4-methyl-2-oxo-2H-chromen-2-ones by oxidation using selenium dioxide. 6- and 7-Alkoxy-4-methyl-2H-chromenes were obtained with yields of 57-85%. Corresponding 4-carbaldehyde derivatives were prepared with yields of 41-67%. Thiosemicarbazones of these aldehydes with D-galactose moiety were synthesized by reaction of these aldehydes with N-(2,3,4,6-tetra-O-acetyl-β-Dgalactopyranosyl) thiosemicarbazide with yields of 62-74%. These thiosemicarbazones were screened for their antibacterial and antifungal activities in vitro against bacteria, such as Staphylococcus aureus, Escherichia coli, and fungi, such as Aspergillus niger, Candida albicans. Several compounds exhibited strong inhibitory activity with MIC values of 0.78- 1.56 μM, including 8a (against S. aureus, E. coli, and C. albicans), 8d (against E. coli and A. niger), 9a (against S. aureus), and 9c (against S. aureus and C. albicans).

Selectivity changes of acetone transformation over ZSM-5 zeolites with different acido-basic properties

1989 ◽  
Vol 54 (8) ◽  
pp. 2054-2063 ◽  
Author(s):  
Jiří Čejka ◽  
Ludmila Kubelková ◽  
Pavel Jírů
Keyword(s):  
Main Product ◽  
High Conversion ◽  
Total Conversion ◽  
Basic Properties ◽  
Product Composition ◽  
Conversion Level ◽  
Integral Reactor ◽  
Low Activity ◽  
High Conversion Level

Acetone transformation catalyzed by HZSM-5 and NaZSM-5 zeolites and by zeolites modified with basic oxides was studied in an integral reactor at a temperature of 350 °C. Modification of acido-basic properties of ZSM-5 zeolites resulted both in the total conversion changes and in the essential changes in the product composition. Isobutene was found to be the main product over HZSM-5 zeolites exhibiting low activity, while aromatics prevailed when high conversion level was attained. Classical condensation of acetone yielding mesityloxide and phorones was observed over NaZSM-5 zeolites impregnated with CaO and ZnO.

Urobiliverdin, a New Bile Pigment Deriving from Uroporphyrin

1983 ◽  
Vol 38 (9-10) ◽  
pp. 753-757 ◽  
Author(s):  
Eva Benedikt ◽  
Hans-Peter Köst
Keyword(s):  
Carboxylic Acid ◽  
Main Product ◽  
Aminolevulinic Acid ◽  
Chromic Acid ◽  
Bile Pigment ◽  
Enzyme Extract ◽  
Crude Enzyme Extract ◽  
Chromatographic Behaviour ◽  
Vis Spectroscopy ◽  
Rhodopseudomonas Spheroides

5-Aminolevulinic acid is incubated with a crude enzyme extract from Rhodopseudomonas spheroides, mutant R 26. The formed porphyrins (main product: uroporphyrin III) are isolated. Incorporation of iron, ring-splitting by coupled oxydation and subsequent iron removal leads to a mixture of pigments, from which urobiliverdin, a new bile pigment with eight carboxylic acid side chains, is isolated. It is characterized by its chromatographic behaviour, chromic acid degra­dation and UV-vis spectroscopy.

scholarly journals 7-Bromo-[1,2,5]selenadiazolo[3,4-d]pyridazin-4(5H)-one

Molbank ◽  
10.3390/m1229 ◽  
2021 ◽  
Vol 2021 (2) ◽  
pp. M1229
Author(s):  
Timofey N. Chmovzh ◽  
Oleg A. Rakitin
Keyword(s):  
Mass Spectrometry ◽  
Heterocyclic System ◽  
High Resolution Mass Spectrometry ◽  
Uv Spectroscopy ◽  
Hydrolysis Product ◽  
Selenium Dioxide ◽  
Biologically Active ◽  
Photovoltaic Materials ◽  
Organic Photovoltaic Materials ◽  
Ir And Uv Spectroscopy

New heterocyclic systems containing 1,2,5-chalcogenadiazoles are of great interest for the creation of organic photovoltaic materials and biologically active compounds. In this communication, 3,6-dibromopyridazine-4,5-diamine was investigated in reaction with selenium dioxide in order to obtain 4,7-dibromo-[1,2,5]selenadiazolo[3,4-d]pyridazine. We found that 7-bromo-[1,2,5]selenadiazolo[3,4-d]pyridazin-4(5H)-one, the first representative of the new heterocyclic system, was isolated as a hydrolysis product of the corresponding 4,7-dibromoderivative. The structure of the newly synthesized compound was established by means of elemental analysis, high-resolution mass spectrometry, 1H, 13C NMR, IR and UV spectroscopy, and mass spectrometry.

scholarly journals Kinetics and Mechanism of the Change of the 4-Nitrobenzylthio-System into 4,4′-Diformylazoxybenzene in Alkaline Dioxane-Water Media

1985 ◽  
Vol 40 (11) ◽  
pp. 1128-1132
Author(s):  
Y. Riad ◽  
Adel N. Asaad ◽  
G.-A. S. Gohar ◽  
A. A. Abdallah
Keyword(s):  
Acetic Acid ◽  
Sodium Hydroxide ◽  
Rate Constants ◽  
Main Product ◽  
Reaction Medium ◽  
Aqueous Dioxane ◽  
Proton Abstraction ◽  
First Order ◽  
Water Media ◽  
Different Temperatures

Sodium hydroxide reacts with α -(4-nitrobenzylthio)-acetic acid in aqueous-dioxane media to give 4,4'-diformylazoxybenzene as the main product besides 4,4'-dicarboxyazoxybenzene and a nitrone acid. This reaction was kinetically studied in presence of excess of alkali in different dioxane-water media at different temperatures. It started by a fast reversible a-proton abstraction step followed by two consecutive irreversible first-order steps forming two intermediates (α -hydroxy, 4-nitrosobenzylthio)-acetic acid and 4-nitrosobenzaldehyde. The latter underwent a Cannizzaro's reaction, the products of which changed in the reaction medium into 4,4'-diformylazoxybenzene and 4,4'-dicarboxyazoxybenzene. The rate constants and the thermodynamic parameters of the two consecutive steps were calculated and discussed. A mechanism was put forward for the formation of the nitrone acid.Other six 4-nitrobenzyl, aryl sulphides were qualitatively studied and they gave mainly 4,4'-diformylazoxybenzene beside 4,4'-dicarboxyazoxybenzene or its corresponding azo acid.

scholarly journals Impact of Advanced Oxidation Products on Nanofiltration Efficiency

Water ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 541 ◽  
Author(s):  
Renata Żyłła ◽  
Rafał Milala ◽  
Irena Kamińska ◽  
Marcin Kudzin ◽  
Marta Gmurek ◽  
...  
Keyword(s):  
Salicylic Acid ◽  
Membrane Filtration ◽  
Main Product ◽  
Membrane Separation ◽  
Negative Impact ◽  
Microscopic Analysis ◽  
Contact Angles ◽  
Oxidation Products ◽  
Acid Oxidation ◽  
Dihydroxybenzoic Acid

The aim of the work was to determine the influence of salicylic acid (SA) oxidation products on the effectiveness of their further removal in the membrane filtration process. Two commercial polyamide-based polymer membranes, HL (GE Osmonics) and TS80 (TriSepTM), were used and characterized by SEM microscopic analysis, contact angles, and free surface energy. The products of salicylic acid oxidation, 2,3- and 2,5-dihydroxybenzoic acid and catechol, were determined and their impact on the removal of unreacted salicylic acid in the nanofiltration process was investigated. It was also checked to what extent and why they were retained or not by the membranes. The results of the research have shown that the main product of salicylic acid oxidation, 2,3-dihydroxybenzoic acid, has a negative impact on the retention of salicylic acid in the nanofiltration stage, while the other product, catechol, improves SA retention. The determined values of contact angles correlate well with solubility (S) of the tested compounds, which increases in the following order SSA < S2,3-DHBA < SCAT, while the contact angle of the membrane decreases. Nevertheless, it has been shown that some oxidation products can penetrate the environment due to poorer membrane separation properties of these products.

Unusual Synthesis and Cytotoxicity of N-[2-(Benzothiazol-2-Sulfonyl)-1-Ethoxyethoxy]- 5-(Benzothiazol-2-Ylsulfanyl)Pentanamidine

2012 ◽  
Vol 51 (1-2) ◽  
pp. 149-153
Author(s):  
J. Višņevska ◽  
E. Jaščenko ◽  
I. Šestakova ◽  
A. Gulbe ◽  
E. Ābele
Keyword(s):  
Main Product ◽  
High Cytotoxicity

Unusual Synthesis and Cytotoxicity of N-[2-(Benzothiazol-2-Sulfonyl)-1-Ethoxyethoxy]- 5-(Benzothiazol-2-Ylsulfanyl)PentanamidineAddition of N-hydroxy-5-(benzothiazolylthio)pentanamidine toE-2-(2-chlorovinylsulfonyl)benzothiazole in the presence of NaH was studied. The main product of reaction - N-[2-(benzothiazol-2-sulfonyl)-1-ethoxyethoxy]-5-(benzothiazol-2-ylsulfanyl)pentanamidine exhibits high cytotoxicity.

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