Month: April 2022

The reaction of an aromatic heterocycle with a proton is called a protonation. One of articles about this theory is 《Preparation of 3-hydroxy-5-hydroxymethyl-2,4-dimethylpyridine (4-deoxyadermine)》. Authors are Wibaut, J. P.; Uhlenbroek, J. H.; Kooijman, E. C.; Kettenes, D. K..The article about the compound:5-(hydroxymethyl)-2,4-dimethylpyridin-3-ol hydrochloridecas:148-51-6,SMILESS:OC1=C(C)C(CO)=CN=C1C.[H]Cl).Electric Literature of C8H12ClNO2. Through the article, more information about this compound (cas:148-51-6) is conveyed.

The preparation of 4-deoxyadermine (I) as described earlier (CA 38, 32849) was improved to give a total yield 15%. Ac2CH2 (25 g.) was slowly added to a refluxing solution of 21 g. NCCH2CONH2 in 150 ml. EtOH and 3 ml. piperidine to give 97% 2-hydroxy-3-cyano-4,6-dimethylpyridine (II), m. 294°, which on nitration with HNO3 (d. 1.52) in Ac2O at 45-50° gave a 5-nitro derivative (III) m. 268° in 70% yield. A mixture of 50 g. dry III and 65 g. PCl5 was treated with 30 ml. POCl3 and heated to 130°, to yield 71% 2,4-dimethyl-3-nitro-5-cyano-6-chloropyridine, m. 112-13° (EtOH), which was reduced by Pd-C in MeOH and aqueous HCl to give 70-5% 2,4-dimethyl-3-amino 5-aminomethylpyridine di-HCl salt monohydrate (IV), m. 310° (decomposition). The reaction of IV with Ba(NO2)2 and H2SO4 at 0°, and subsequent heating to 90° afforded 45% I, m. 264°.

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Pyrimidine | C4H4N2 – PubChem,
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So far, in addition to halogen atoms, other non-metallic atoms can become part of the aromatic heterocycle, and the target ring system is still aromatic.Dai, Zhen-Yao; Wang, Pu-Sheng; Gong, Liu-Zhu researched the compound: 5-Methylfuran-2(3H)-one( cas:591-12-8 ).Quality Control of 5-Methylfuran-2(3H)-one.They published the article 《Access to chiral γ-butenolides via palladium-catalyzed asymmetric allylic C-H alkylation of 1,4-dienes》 about this compound( cas:591-12-8 ) in Chemical Communications (Cambridge, United Kingdom). Keywords: gamma butenolide preparation; pentadiene alpha angelica lactone allylic alkylation palladium catalyst. We’ll tell you more about this compound (cas:591-12-8).

Allylic C-H alkylation of 1,4-pentadienes with α-angelica lactones has been developed by tri-axial phosphoramidite-palladium catalysis. This reaction can tolerate a range of functional groups under mild conditions, furnishing versatile chiral γ,γ-disubstituted butenolides I (R = Me, i-Pr, Cy, etc.; Ar = C6H5, 4-MeC6H4, 4-FC6H4, etc.) in high yields with good to high levels of stereoselectivity.

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Safety of 5-Methylfuran-2(3H)-one. Aromatic heterocyclic compounds can also be classified according to the number of heteroatoms contained in the heterocycle: single heteroatom, two heteroatoms, three heteroatoms and four heteroatoms. Compound: 5-Methylfuran-2(3H)-one, is researched, Molecular C5H6O2, CAS is 591-12-8, about Photochemistry of 2-butenedial and 4-oxo-2-pentenal under atmospheric boundary layer conditions. Author is Newland, Mike J.; Rea, Gerard J.; Thuner, Lars P.; Henderson, Alistair P.; Golding, Bernard T.; Rickard, Andrew R.; Barnes, Ian; Wenger, John.

Unsaturated 1,4-dicarbonyl compounds, such as 2-butenedial and 4-oxo-2-pentenal are produced in the atm. boundary layer from the oxidation of aromatic compounds and furans. These species are expected to undergo rapid photochem. processing, affecting atm. composition In this study, the photochem. of (E)-2-butenedial and both E and Z isomers of 4-oxo-2-pentenal was investigated under natural sunlight conditions at the large outdoor atm. simulation chamber EUPHORE. Photochem. loss rates, relative to j(NO2), are determined to be j((E)-2-butenedial)/j(NO2) = 0.14 (±0.02), j((E)-4-oxo-2-pentenal)/j(NO2) = 0.18 (±0.01), and j((Z)-4-oxo-2-pentenal)/j(NO2) = 0.20 (±0.03). The major products detected for both species are a furanone (30-42%) and, for (E)-2-butenedial, maleic anhydride (2,5-furandione) (12-14%). The mechanism appears to proceed predominantly via photoisomerization to a ketene-enol species following γ-H abstraction. The lifetimes of the ketene-enol species in the dark from 2-butenedial and 4-oxo-2-pentenal are determined to be 465 s and 235 s, resp. The ketene-enol can undergo ring closure to yield the corresponding furanone, or further unimol. rearrangement which can subsequently form maleic anhydride. A minor channel (10-15%) also appears to form CO directly. This is presumed to be via a mol. elimination route of an initial biradical intermediate formed in photolysis, with an unsaturated carbonyl (detected here but not quantified) as co-product. α-Dicarbonyl and radical yields are very low, which has implications for ozone production from the photo-oxidation of unsaturated 1,4-dicarbonyls in the boundary layer. Photochem. removal is determined to be the major loss process for these species in the boundary layer with lifetimes of the order of 10-15 min, compared to >3 h for reaction with OH.

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Computed Properties of C5H6O2. The fused heterocycle is formed by combining a benzene ring with a single heterocycle, or two or more single heterocycles. Compound: 5-Methylfuran-2(3H)-one, is researched, Molecular C5H6O2, CAS is 591-12-8, about Elucidation of surface active sites by formic acid adsorbed IR studies in the hydrogenation of levulinic acid to valeric acid over rare earth metal doped titania supported nickel catalysts. Author is Peddakasu, Ganga Bhavani; Velisoju, Vijay Kumar; Gutta, Naresh; Medak, Sudhakar; Dumpalapally, Mahesh; Akula, Venugopal.

Titania supported Ni catalyst modified by different lanthanides (La, Ce, Pr and Nd) were evaluated for the one-step conversion of levulinic acid (LA) to valeric acid (VA) using formic acid as a hydrogen source. Among these, the La modified Ni/TiO2 demonstrated better VA yields with an optimum LA to VA mole ratio of 1:3. Pyridine and/or formic acid adsorbed IR studies revealed that presence of weak Lewis and strong basic sites present on the Ni-La/TiO2 surface was the reason for higher VA selectivity. The physicochem. characteristics of the modified Ni-M/TiO2 (M = La, Ce, Pr and Nd) catalysts deduced from H2-TPR, N2O titration, TPD of NH3 and catalytic activity data emphasized a combination of metallic Ni with surface acid-base sites were responsible for the formation of VA in single step. Using aqueous γ-valerolactone, 99% selectivity towards VA was achieved. A plausible reaction mechanism has been proposed based on the kinetic data obtained at moderate temperatures and ambient pressures.

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Pyrimidine | C4H4N2 – PubChem,
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Epoxy compounds usually have stronger nucleophilic ability, because the alkyl group on the oxygen atom makes the bond angle smaller, which makes the lone pair of electrons react more dissimilarly with the electron-deficient system. Compound: 5-Methylfuran-2(3H)-one, is researched, Molecular C5H6O2, CAS is 591-12-8, about Catalyst-controlled regioselective nitrosocarbonyl aldol reaction of deconjugated butenolides.Category: pyrimidines.

An unprecedented regiodivergent nitrosocarbonyl aldol reaction of γ-substituted deconjugated butenolides was described. While Lewis base catalyst quinidine leveraged O-selective nitrosocarbonyl aldol reaction exclusively at the γ-position of deconjugated butenolides to produce γ-substituted-butenolides I [R = Me, n-Pr, PhCH2, etc.; R1 = t-BuO, OCH2CH=CH2, PhCH2O, 4-MeC6H4, etc.], Lewis acid catalyst Cu(OTf)2 steered the competitive N-selective nitrosocarbonyl aldol reaction at the β-position, resulting in hetero-β,γ-difunctionalized-butenolides II [R2 = Me, Ph, 4-MeC6H4CH2, PhCH2; R3 = t-Bu, PhCH2, 1-naphthyl, etc.]. Both processes were amenable to a broad range of substrates and scalable, while the latter one represented a rare example of one-pot hetero-β,γ-difunctionalization of butenolide scaffolds.

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Related Products of 591-12-8. Aromatic compounds can be divided into two categories: single heterocycles and fused heterocycles. Compound: 5-Methylfuran-2(3H)-one, is researched, Molecular C5H6O2, CAS is 591-12-8, about Furfural hydrogenation, hydrodeoxygenation and etherification over MoO2 and MoO3: A combined experimental and theoretical study. Author is Kojcinovic, Aleksa; Kovacic, Zan; Hus, Matej; Likozar, Blaz; Grilc, Miha.

Valorization of lignocellulosic biomass, particularly catalytic hydrotreatment of hemicellulose-based furfural (FUR), has been studied for the production of value-added chems. A three-phase batch reactor has been used for hydrotreatment in isopropanol over various com. available unsupported MoOx catalysts, at various temperatures (170-230°C), pressures (0-80 bar H2), catalyst loadings (0-2 weight%), and reactant concentrations (5-20 weight%). No significant difference in catalytic activity or selectivity has been observed among the three different MoO3 and one MoO2 catalysts, while NiMo/Al2O3, Mo2C and WO3 were much less active. Data-points collected have been used to propose a detailed reaction pathway network for a micro-kinetic model, which also took into consideration the thermodn., and adsorption, desorption, and surface reaction kinetics. The alcoholysis of FUR yielded valuable iso-Pr levulinate (IPL) as the major product under all tested reaction conditions, while other value-added compounds (furfuryl alc., iso-Pr furfuryl ether, furfuryl acetone, angelica lactone) were observed in smaller quantities. It was found that neither the presence nor the absence of the gaseous H2 pressure contributes to the global reaction rate, or selectivity, since the solvent acts as a sufficient hydrogen donor. Addnl., d. functional theory (DFT) calculations provided further insight into the active planes present by the implementation of the Wulff construction. Furthermore, the reaction mechanism was explained based on reaction energies, which were in silico determined and compared for several surfaces. The results were consistent with the characterization and activity-testing results. The furfural ring-opening reaction, yielding valuable IPL in the absence of gaseous H2, over a cheap bulk MoOx is reported for the first time.

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Hommes, Arne; ter Horst, Arie Johannes; Koeslag, Meine; Heeres, Hero Jan; Yue, Jun published an article about the compound: 5-Methylfuran-2(3H)-one( cas:591-12-8,SMILESS:O=C1OC(C)=CC1 ).HPLC of Formula: 591-12-8. Aromatic heterocyclic compounds can be classified according to the number of heteroatoms or the size of the ring. The authors also want to convey more information about this compound (cas:591-12-8) through the article.

The hydrogenation of levulinic acid (LA) to γ-valerolactone (GVL) was performed in perfluoroalkoxy alkane capillary microreactors packed with a carbon-supported ruthenium (Ru/C) catalyst with an average particle diameter of 0.3 or 0.45 mm. The reaction was executed under an upstream gas-liquid slug flow with 1,4-dioxane as the solvent and H2 as the hydrogen donor in the gas phase. Operating conditions (i.e., flow rate and gas to liquid flow ratio, pressure, temperature and catalyst particle size) were varied in the microreactor to determine the influence of mass transfer and kinetic characteristics on the reaction performance. At 130°C, 12 bar H2 and a weight hourly space velocity of the liquid feed (WHSV) of 3.0 gfeed/(gcat·h), 100% LA conversion and 84% GVL yield were obtained. Under the conditions tested (70-130°C and 9-15 bar) the reaction rate was affected by mass transfer, given the notable effect of the mixture flow rate and catalyst particle size on the LA conversion and GVL yield at a certain WHSV. A microreactor model was developed by considering gas-liquid-solid mass transfer therein and the reaction kinetics estimated from the literature correlations and data. This model well describes the measured LA conversion for varying operating conditions, provided that the internal diffusion and kinetic rates were not considered rate limiting. Liquid-solid mass transfer of hydrogen towards the external catalyst surface was thus found dominant in most experiments The developed model can aid in the further optimization of the Ru/C catalyzed levulinic acid hydrogenation in packed bed microreactors.

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Pyrimidine | C4H4N2 – PubChem,
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The preparation of ester heterocycles mostly uses heteroatoms as nucleophilic sites, which are achieved by intramolecular substitution or addition reactions. Compound: 5-Methylfuran-2(3H)-one( cas:591-12-8 ) is researched.Computed Properties of C5H6O2.Dell’Acqua, Andrea; Stadler, Bernhard M.; Kirchhecker, Sarah; Tin, Sergey; de Vries, Johannes G. published the article 《Scalable synthesis and polymerization of a β-angelica lactone derived monomer》 about this compound( cas:591-12-8 ) in Green Chemistry. Keywords: angelica lactone monomer ROMP film property. Let’s learn more about this compound (cas:591-12-8).

Bio-based levulinic acid is easily ring-closed to α-angelica lactone (α-AL). The α-AL can be isomerized to the conjugated β-AL under the influence of base, but since this is an equilibrium mixture it is very hard to devise a scalable process that would give pure β-AL. This problem was circumvented by distilling the equilibrium mixture to obtain a 90 : 10 mixture of β- and α-AL in 88% yield. This mixture was used for Diels-Alder reactions on 3 terpenes and on cyclopentadiene in up to 100 g scale. The latter DA adduct was subjected to a ROMP reaction catalyzed by the Grubbs II catalyst. The resulting polymer has some similarities to poly-norbornene but is more polar. The polymer can be processed into films with very good transparency.

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Pyrimidine | C4H4N2 – PubChem,
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The preparation of ester heterocycles mostly uses heteroatoms as nucleophilic sites, which are achieved by intramolecular substitution or addition reactions. Compound: 5-Methylfuran-2(3H)-one( cas:591-12-8 ) is researched.Product Details of 591-12-8.Robichaux, Laura; Kendell, Shane published the article 《Mechanistic insights into furfuryl alcohol based biofuel production over phosphotungstate catalysts》 about this compound( cas:591-12-8 ) in Reaction Kinetics, Mechanisms and Catalysis. Keywords: furfuryl alc phosphotungstate catalyst alkylation charge transfer. Let’s learn more about this compound (cas:591-12-8).

A one-step direct alkylation method for synthesizing Bu levulinate from Bu alc. and furfuryl alc. has been explored. This process is carried out under reflux, at ∼ 120 °C for 2 h and utilizes a catalyst. Catalysts are based on phosphotungstic acid; the catalysts are modified via cation exchange, producing several cesium, copper and silver based phosphotungstates. Of these, the greatest activity and selectivity towards Bu levulinate was achieved over the Cu0.5H2[PW12O40] catalyst, with 100% conversion and a Bu levulinate selectivity of 69%. Various side reactions are also observed, with products that may also be suitable for biofuel applications. A detailed product anal. has been performed, and likely reaction schemes for these products have been determined Overall, these results demonstrate an efficient method for Bu levulinate production from biomass-derived sources.

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Epoxy compounds usually have stronger nucleophilic ability, because the alkyl group on the oxygen atom makes the bond angle smaller, which makes the lone pair of electrons react more dissimilarly with the electron-deficient system. Compound: 5-Methylfuran-2(3H)-one, is researched, Molecular C5H6O2, CAS is 591-12-8, about Conversion of levulinic acid to γ-valerolactone over ultra-thin TiO2 nanosheets decorated with ultrasmall Ru nanoparticle catalysts under mild conditions.HPLC of Formula: 591-12-8.

Herein, we demonstrate that quantum-sized Ru dot decorated ultra-thin anatase TiO2 nanosheets with exposed (001) facets could exhibit highly efficient catalytic activity during the conversion of levulinic acid to γ-valerolactone at room temperature The support effect has been largely attributed to the high energy of TiO2 (001) which can lead to a stronger interaction between the support and the metal. The surface of Ru/TiO2-n contains more Ru(0) and results in higher activity and selectivity.

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