Synthesis of 2-Acetoacetyl- and 2-OxaIoacetyl-1,3-indandiones and Related Compounds

1988 ◽  
Vol 43 (7) ◽  
pp. 897-900 ◽  
Author(s):  
W. S. Hamama ◽  
M. Hammouda ◽  
E. M. Afsah
Keyword(s):  
Ethyl Acetate ◽  
Mannich Reaction ◽  
Selenium Dioxide ◽  
The Other ◽  
Molar Ratio ◽  
Diethyl Oxalate ◽  
Phenyl Hydrazine ◽  
Claisen Condensation ◽  
Other Hand ◽  
Related Compounds

Abstract Claisen condensation of 2-acetyl-1,3-indandione (1) with ethyl acetate afforded the 2-acetoacetyl-1,3-indandione (2) which upon treatment with benzylamine and paraformaldehyde in a molar ratio of (1:1:2) and (1:2:4) afforded the piperidinone and the diazabicyclic derivative (4) and (5) respectively. On the other hand, Claisen condensation of 1 with diethyl oxalate yielded two products (6) and (9). The behaviour of 6 towards phenyl hydrazine, and of 9 towards selenium dioxide and double Mannich reaction were also investigated.

Degradation of chlorpyriphos in water by advanced oxidation processes

2010 ◽  
Vol 10 (1) ◽  
pp. 1-6 ◽  
Author(s):  
R. Murillo ◽  
J. Sarasa ◽  
M. Lanao ◽  
J. L. Ovelleiro
Keyword(s):  
Reaction Time ◽  
Light Source ◽  
Advanced Oxidation Processes ◽  
Advanced Oxidation ◽  
The Other ◽  
Molar Ratio ◽  
Optimum Conditions ◽  
Oxidation Processes ◽  
Other Hand ◽  
Initial Ph

The degradation of chlorpyriphos by different advanced oxidation processes such as photo-Fenton, TiO2, TiO2/H2O2, O3 and O3/H2O2 was investigated. The photo-Fenton and TiO2 processes were optimized using a solar chamber as light source. The optimum dosages of the photo-Fenton treatment were: [H2O2]=0.01 M; [Fe3 + ]=10 mg l−1; initial pH = 3.5. With these optimum conditions total degradation was observed after 15 minutes of reaction time. The application of sunlight was also efficient as total degradation was achieved after 60 minutes. The optimum dosage using only TiO2 as catalyst was 1,000 mg l−1, obtaining the maximum degradation at 20 minutes of reaction time. On the other hand, the addition of 0.02 M of H2O2 to a lower dosage of TiO2 (10 mg l−1) provides the same degradation. The ozonation treatment achieved complete degradation at 30 minutes of reaction time. On the other hand, it was observed that the degradation was faster by adding H2O2 (H2O2/O3 molar ratio = 0.5). In this case, total degradation was observed after 20 minutes.

scholarly journals Determination of the Ratios of Ligands to Metal Ion of some Metal Complexes of Triazoles by Using Eleetronie Speetra in Organie Solvents

2004 ◽  
Vol 1 (1) ◽  
pp. 110-115
Author(s):  
Baghdad Science Journal
Keyword(s):  
Solid State ◽  
Metal Complexes ◽  
Electronic Spectra ◽  
Metal Ion ◽  
The Other ◽  
Molar Ratio ◽  
Other Hand

We found that 4,5- diphenyl- 3(2- propynyl) thio- 1??-triazole [1? forms a complex with Pd (11) ion of ratio 1:1 which absorbs light in CH2CI2 at 400 nm, and 4,5- diphenyl- 3(2- propenyl) thio- 1,2,4- triazole [II] forms complexes with Pd (II) ion of ratio 1:1 which absorbs light at 390 nm, and of ratio 2:1 which absorbs light at 435 nm. On the other hand, we found that the new derivative 4- phenyl- 5( p- amino phenyl) -3- mercapto- 1,2,4- triazole ?111? forms complexes with Cu (II) ion of the ratio 1:1 which absorbs light at 380 nm, with Ni (II) ion of the ratio 3:1 which absorbs light at 358 nm; and with Co (11) ion of the ratio 3.2:1 which absorbs light at 588 nm. The ratio of the complexes were determined by measuring the electronic spectra of the complexes in CH2G2 and (CH^NCHO at different concentrations ofthe ligands and f?xed ' •' of the metal ion in every case, then applying the molar ratio plots on the data. Our results were confirmed by precipitating most ofthe above complexes in solid state, and then each complex was analyzed elementally.

scholarly journals Structural and Functional Changes of Reconstituted High-Density Lipoprotein (HDL) by Incorporation of α-synuclein: A Potent Antioxidant and Anti-Glycation Activity of α-synuclein and apoA-I in HDL at High Molar Ratio of α-synuclein

Molecules ◽  
2021 ◽  
Vol 26 (24) ◽  
pp. 7485
Author(s):  
Kyung-Hyun Cho
Keyword(s):  
Amino Acids ◽  
Secondary Structure ◽  
Expression System ◽  
Lipoprotein Metabolism ◽  
The Other ◽  
Ldl Oxidation ◽  
Molar Ratio ◽  
Binding Ability ◽  
Functional Changes ◽  
Other Hand

α-synuclein (α-syn) is a major culprit of Parkinson’s disease (PD), although lipoprotein metabolism is very important in the pathogenesis of PD. α-syn was expressed and purified using the pET30a expression vector from an E. coli expression system to elucidate the physiological effects of α-syn on lipoprotein metabolism. The human α-syn protein (140 amino acids) with His-tag (8 amino acids) was expressed and purified to at least 95% purity. Isoelectric focusing gel electrophoresis showed that the isoelectric point (pI) of α-syn and apoA-I were pI = 4.5 and pI = 6.4, respectively. The lipid-free α-syn showed almost no phospholipid-binding ability, while apoA-I showed rapid binding ability with a half-time (T1/2) = 8 ± 0.7 min. The α-syn and apoA-I could be incorporated into the reconstituted HDL (rHDL, molar ratio 95:5:1:1, palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC):cholesterol:apoA-I:α-syn with the production of larger particles (92 Å) than apoA-I-rHDL (86 and 78 Å) and α-syn-rHDL (65 Å). An rHDL containing both apoA-I and α-syn showed lower α-helicity around 45% with a red shift of the Trp wavelength maximum fluorescence (WMF) from 339 nm, while apoA-I-HDL showed 76% α-helicity and 337 nm of WMF. The denaturation by urea addition showed that the incorporation of α-syn in rHDL caused a larger increase in the WMF than apoA-I-rHDL, suggesting that the destabilization of the secondary structure of apoA-I by the addition of α-syn. On the other hand, the addition of α-syn induced two-times higher resistance to rHDL glycation at apoA-I:α-syn molar ratios of 1:1 and 1:2. Interestingly, low α-syn in rHDL concentrations, molar ratio of 1:0.5 (apoA-I:α-syn), did not prevent glycation with more multimerization of apoA-I. In the lipid-free and lipid-bound state, α-syn showed more potent antioxidant activity than apoA-I against cupric ion-mediated LDL oxidation. On the other hand, microinjection of α-syn (final 2 μM) resulted in 10% less survival of zebrafish embryos than apoA-I. A subcutaneous injection of α-syn (final 34 μM) resulted in less tail fin regeneration than apoA-I. Interestingly, incorporation of α-syn at a low molar ratio (apoA-I:α-syn, 1:0.5) in rHDL resulted destabilization of the secondary structure and impairment of apoA-I functionality via more oxidation and glycation. However, at a higher molar ratio of α-syn in rHDL (apoA-I:α-syn = 1:1 or 1:2) exhibited potent antioxidant and anti-glycation activity without aggregation. In conclusion, there might be a critical concentration of α-syn and apoA-I in HDL-like complex to prevent the aggregation of apoA-I via structural and functional enhancement.

The Effect of Lithium Alkoxides on Deprotonizations by Superbases Made from Butyllithium and Potassium tert-Pentoxide

1993 ◽  
Vol 58 (6) ◽  
pp. 1445-1451 ◽  
Author(s):  
Lubomír Lochmann ◽  
Hana Jakubův ◽  
Lambert Brandsma
Keyword(s):  
High Reactivity ◽  
The Other ◽  
Molar Ratio ◽  
Side Chain ◽  
Other Hand

The presence or absence of lithium tert-pentoxide (t-PeOLi) in Superbases, prepared from butyllithium (BuLi) and potasium tert-pentoxide (t-PeOK), affects the metallation rate of toluene only slightly, the rate factors being between 1.0 and 0.3. Thus, lithium alkoxide is not essential for the high reactivity of Superbases. However, the ring-to-side chain metallation ratio is increased in the presence of t-PeOLi. On the other hand, an excess of t-PeOK (molar ratio t-PeOK/BuLi ≥ 3)considerably increases in the rate and yield of the side chain methallation of toluene and suppresses its ring mrtallation. In this way, alkoxides enable some control on regioselectivity in Superbase reactions.

Alkylation by secondary alcohols. I. The reaction of xanthydrol with some N1-monosubstituted sulfanilamides and related compounds

1967 ◽  
Vol 45 (13) ◽  
pp. 1411-1424 ◽  
Author(s):  
R. E. Moskalyk ◽  
L. G. Chatten
Keyword(s):  
Nitrogen Atom ◽  
Tautomeric Form ◽  
Heterocyclic Ring ◽  
The Other ◽  
Secondary Alcohols ◽  
Amino Group ◽  
Aromatic Character ◽  
Carbonium Ion ◽  
Other Hand ◽  
Related Compounds

Sulfanilamides were found to undergo alkylation with xanthydrol, yielding either mono- or di-xanthenyl derivatives. The site of substitution, common to all sulfanilamides having a free p-amino group, was shown to be the N4-position in the sulfanilamide molecule. Three additional unique reactive sites were observed. Sulfanilamides carrying a thiazole, thiadiazole, or pyridazine substituent in the N1-position were also alkylated on the annular nitrogen atom of the heterocyclic ring, the reaction having occurred from the imido tautomeric form. Sulfisoxazole (IK), on the other hand, reacted from the amido form to give the N1,N4-dixanthenyl derivative. Sulfadimethoxine (Ih) was substituted at carbon, as well as at nitrogen, to yield N4-xanthenyl-N1-(2,6-dimethoxy-5-(9-xanthenyl)-4-pyrimidyl)sulfanilamide.Sulfanilamides possessing pKa values of about 5.5 were found to be sufficiently acidic to catalyze their own reaction with xanthydrol, and no external catalyst was necessary. The exceptional ease of formation of the xanthylium ion was postulated to be associated with the resulting stability of this carbonium ion by virtue of its acquired aromatic character.

scholarly journals Synthesis of Ca-hydroxyapatite Bioceramic from Egg Shell and its Characterization

1970 ◽  
Vol 43 (4) ◽  
pp. 501-512 ◽  
Author(s):  
Samina Ahmed ◽  
Mainul Ahsan
Keyword(s):  
Crystalline Phase ◽  
Hexagonal Structure ◽  
The Other ◽  
Molar Ratio ◽  
Apatite Phase ◽  
Other Hand ◽  
Ft Ir ◽  
Egg Shell

Ca-hydroxyapatite (HA) was synthesised from egg shell under different conditions and characterised by using AAS, FT-IR, XRD, SEM and EDS techniques. The results of these analyses combined together indicate that sintered HA sample1 resembles the feature of pure and single apatite phase having hexagonal structure. A Ca/P molar ratio of 1.69 was achieved in this case. On the other hand HA obtained from calcined egg shell is a combination of both amorphous and crystalline phase and revealed a sub-stoichiometric Ca-deficient apatite form with a Ca/P ratio of 1.50. Keywords: Ca-hydroxyapatite, Biomaterials, Hexagonal, stoichiometric apatite, Ca-deficient apatite   doi: 10.3329/bjsir.v43i4.2240 Bangladesh J. Sci. Ind. Res. 43(4), 501-512, 2008

Synthesis of Some Diazepinones, Oxazepinones, Pyrimidoquinazolinones and Related Compounds from 1,4-Bis(ethoxycarbonyl)-2,5-diamino-1,4-cyclohexadiene

1980 ◽  
Vol 35 (11) ◽  
pp. 1395-1397 ◽  
Author(s):  
Fathy A. Amer ◽  
El-Sayed Afsah ◽  
Mohamed A. Metwally ◽  
Mohamed T. El-Zimaity
Keyword(s):  
Polyphosphoric Acid ◽  
The Other ◽  
Spectroscopic Methods ◽  
Other Hand ◽  
Related Compounds

AbstractInteraction of o-phenylenediamine with 1,4-Bis-(ethoxycarbonyl)-2,5-diamino-1,4-cyclo-hexadiene (1) gave 2, which cyclised to the hexahydrobenzodiazepinone (3). On the other hand, interaction of 1 with o-aminophenol, gave compound 4 which on treatment with polyphosphoric acid gave the tetrahydrobis-benzooxazepinone (11). Treatment of 1 with phenylisothiocyanate and formamide afforded the dithiopyrimidoquinazolinone (8) and the tetrahydropyrimidoquinazolinone (9), while the interaction of 1 with benzenesulphonyl-chloride gave dibenzenesulphonamido-cyclohexadiene dicarboxylate (10). The structure of these compounds was established by chemical and spectroscopic methods.

Stereocontrolled catalytic hydrogenations of 3-oxocholestanes and some related compounds to the corresponding axial 3-alcohols

1980 ◽  
Vol 58 (11) ◽  
pp. 1061-1068 ◽  
Author(s):  
Masayoshi Ishige ◽  
Michio Shiota
Keyword(s):  
Carbonyl Group ◽  
Cobalt Catalyst ◽  
Solvent Polarity ◽  
The Other ◽  
Nonpolar Solvents ◽  
Ketone Carbonyl Group ◽  
Other Hand ◽  
Ketone Carbonyl ◽  
Related Compounds ◽  
Alcohol Formation

Catalytic hydrogenations of 5α-cholestan-3-ones and related compounds with Urushibara nickel A catalyst in cyclohexane gave a distinct preponderance of unstable axial 3α-ols. Product ratios of axial alcohols decreased with increasing solvent polarity. For 3-oxo-5α-steroids, the cobalt catalyst was less selective for the axial alcohol formation. On the other hand, conversion of 5β-cholestan-3-one into the corresponding axial 3β-ol was most successfully attained by hydrogenation catalyzed by Urushibara cobalt A catalyst in methanol. For such a 5β-ketone, alcoholic media with higher polarities were more favorable for giving the product rich in axial alcohol. The stereochemistry of the products obtained from hydrogenations conducted in nonpolar solvents may be understood in terms of the steric congestion around the ketone carbonyl group. However, when alcohols were used as solvents, the product ratios obtained did not correlate well with the congestion ratios of substrates.

Activity Comparison of MCM-41 and V-MCM-4 Catalysts for Ethanol Selective Oxidation and DRIFTS Analysis

2009 ◽  
Vol 7 (1) ◽  
Author(s):  
Yesim Gucbilmez ◽  
Timur Dogu ◽  
Suna Balci
Keyword(s):  
Hydrogen Atom ◽  
Gas Phase ◽  
Selective Oxidation ◽  
The Other ◽  
Lattice Oxygen ◽  
Molar Ratio ◽  
Surface Species ◽  
Other Hand ◽  
Activity Comparison ◽  
Mcm 41

The activity of a V-MCM-41 catalyst with a V/Si molar ratio of 0.04 was compared with the activity of a pure MCM-41 catalyst and some DRIFTS studies were performed in order to understand the mechanism of selective oxidation of ethanol. V-MCM-41 was found to be much more active than pure MCM-41, favouring the formation of high amounts of ethylene over 300°C. MCM-41, on the other hand, was found to favour the formation of acetaldehyde over ethylene at all studied temperatures. It was shown by reaction findings that over V-MCM-41, ethylene was produced mainly in the presence of gas phase oxygen whereas acetaldehyde was produced using the lattice oxygen even in the absence of gas phase oxygen. DRIFTS studies indicated the formation of acetaldehyde molecules from acetate-like surface species which were formed by the removal of a hydrogen atom from the ?-carbon of chemisorbed ethoxy species by the help of the lattice oxygen. On the other hand, removal of a hydrogen atom from the ?-carbon of the ethoxy species, in the presence of gas phase oxygen, resulted in the formation of vinyl-like surface species which then yielded ethylene molecules.

Pyrimidine Derivatives and Related Compounds, IX / Preparation of 5-Aminopyrazolo[1,5-a]pyrimidines and of Oxazino[4,5 : 5,6]pyrazolo[1,5-a]pyrimidines, a New Ring System

1977 ◽  
Vol 32 (12) ◽  
pp. 1478-1481 ◽  
Author(s):  
Mohamed Hilmy Elnagdi ◽  
Sherif Mahmoud Fahmy ◽  
Mohamed Riffaat Hamza Elmoghayar ◽  
Abdalla Mohamed Negm
Keyword(s):  
Acetic Acid ◽  
Pyrimidine Derivative ◽  
Ring System ◽  
The Other ◽  
Reaction Products ◽  
Pyrimidine Derivatives ◽  
Other Hand ◽  
Related Compounds

Whereas the 5-aminopyrazole derivatives (1 a, b) react with ethyl β-amino-β-trichloro-methylmethylenecyanoacetate (2) in basic media to yield the corresponding 5-aminopyrazolo[1,5-a]pyrimidine derivatives (3a, b), the reaction of la, b with 2 in refluxing acetic acid has afforded oxazino[4,5:5,6]pyrazolo[1,5-a]pyrimidine derivatives.5-Amino-3-phenyl-4-phenylazopyrazole (12) reacted with 2 in refluxing pyridine to yield the 5-amino-2-phenyl-3-phenylazopyrazolo[1,5-a]pyrimidine derivative (18). On the other hand, the reaction of 12 and 2 in refluxing acetic acid has afforded a mixture of the oxazino[4,5:5′,6′]pyrazolo[1,5-a]pyrimidine derivatives (14) and the pyrazolo[3,4-d]-astriazine derivatives (15). The mechanism of the formation of reaction products is discussed.

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