Day: April 19, 2022

Most of the natural products isolated at present are heterocyclic compounds, so heterocyclic compounds occupy an important position in the research of organic chemistry. A compound: 591-12-8, is researched, SMILESS is O=C1OC(C)=CC1, Molecular C5H6O2Journal, Catalysis Today called Mechanism study on asymmetric Michael addition reaction between alkynone and α-angelica lactone catalyzed by chiral N, N’-dioxide-Sc(III) complex, Author is Zuo, Yini; Meng, Xiangxiang; Hu, Changwei; Li, Jing; Su, Zhishan, the main research direction is butenolide alkynone scandium catalyst Michael addition mechanism bond order.COA of Formula: C5H6O2.

The reaction mechanism and enantioselectivity of asym. Michael addition reaction between alkynone (R1) with α-angelica lactone (R2) catalyzed by chiral N, N’-dioxide-Sc(III) complex were investigated at the M06/6-31G(d,p) (acetonitrile, SMD) level. The α-angelica lactone substrate could isomerize to the active enolized form in the presence of Sc(OTf)3 reagent, assisted by the counter trifluoromethanesulfonate anion OTf-. The alkynone substrate and enolized angelica lactone (or its anion) coordinated to Sc(III) center of N,N’-dioxide-Sc(III) complex catalyst simultaneously, forming a high active hexacoordinate-Sc(III) complex. The catalytic reaction occurred via a two-step mechanism, in which C2-Cγ bond formation was predicted to be the chirality-controlling step as well as the rate-determining step, affording predominant S-enantiomer. The counterion OTf- facilitated C-H construction as a proton-shuttle, producing mainly E-configuration product observed in experiment The steric repulsion from the ortho-substituent of amide moiety as well as the chiral backbone of N, N’-dioxide-Sc(III) catalyst played the key role for chiral induction in the asym. reaction. The less destabilizing Pauli repulsion and more stabilizing attractive interaction, especially the orbital interaction, along the si-face attack pathway enhanced the enantiodifference of the two competing pathways for high enantioselectivity. The energy barriers for E/Z isomerization of S or R-enantiomer assisted by HOTf was as high as 34.6-35.0 kcal mol-1, indicating that the product with Z-conformation was difficult to be obtained. These results were in good agreement with exptl. observations.

Compounds in my other articles are similar to this one(5-Methylfuran-2(3H)-one)COA of Formula: C5H6O2, you can compare them to see their pros and cons in some ways,such as convenient, effective and so on.

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Pyrimidine | C4H4N2 – PubChem,
Pyrimidine – Wikipedia

In general, if the atoms that make up the ring contain heteroatoms, such rings become heterocycles, and organic compounds containing heterocycles are called heterocyclic compounds. An article called Nicotinamide inhibitors, published in 1952, which mentions a compound: 148-51-6, Name is 5-(hydroxymethyl)-2,4-dimethylpyridin-3-ol hydrochloride, Molecular C8H12ClNO2, Name: 5-(hydroxymethyl)-2,4-dimethylpyridin-3-ol hydrochloride.

3,5-Pyridinedicarboxylic acid, 2,3-pyrazinedicarboxylic acid, 4-methyl-2,3-pyridinedicarboxylic acid, 2,3-pyrazinedicarboxamide, 3-bromopyridine, 2-methyl-3-amino-4,5-bis(aminomethyl)pyridine, N-thiazolylpyrazinamide, N,N-dimethylpyrazinamide, N-methylpyrazinamide, N-pyrazinylthiourea, N-(hydroxymethyl)pyrazinamide, diethyl N-pyrazinoylaspartate, N-pyrazinoylpiperidine, N-isobutylpyrazinamide, N-(2-pyridyl)pyrazinamide, N-(3-pyridyl)pyrazinamide, N-phenylpyrazinamide, N-hexadecylpyrazinamide, 3-pyrazinoylaminoquinoline, N-(2-hydroxyethyl)-N’-pyrazinoylethylenediamine, 3-hydroxy-6-pyridazinecarboxamide, 2-pyrrolidone-5-carboxamide, 1-thiazolyl-2-pyrrolecarboxamide, desoxypyridoxine, salicylamide, furoic acid, furanilide, pyrazinohydrazide, 1-carbethoxy-4(1,2-dicarbethoxyethyl)piperazine, N-(p-methoxybenzyl)pyrazinamide, pyrazinohydroxamic acid, and Et N-pyrazinoyl-β-alanate had no anti-nicotinamide activity when tested against Lactobacillus arabinosus and none stimulated growth. Pyrazinamide, pyrazinoic acid, and 2-sulfanilamido-5-nitropyridine reversibly inhibited the action of nicotinamide on the organism. Pyrazinamide was not a nicotinamide antagonist for rats or chicks.

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Pyrimidine | C4H4N2 – PubChem,
Pyrimidine – Wikipedia

Electric Literature of C5H11NO. 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: (S)-3-Methoxypyrrolidine, is researched, Molecular C5H11NO, CAS is 120099-61-8, about Ultrapotent vinblastines in which added molecular complexity further disrupts the target tubulin dimer-dimer interface. Author is Carney, Daniel W.; Lukesh, John C. III; Brody, Daniel M.; Brutsch, Manuela M.; Boger, Dale L..

Approaches to improving the biol. properties of natural products typically strive to modify their structures to identify the essential pharmacophore, or make functional group changes to improve biol. target affinity or functional activity, change phys. properties, enhance stability, or introduce conformational constraints. Aside from accessible semisynthetic modifications of existing functional groups, rarely does one consider using chem. synthesis to add mol. complexity to the natural product. In part, this may be attributed to the added challenge intrinsic in the synthesis of an even more complex compound Herein, we report synthetically derived, structurally more complex vinblastines inaccessible from the natural product itself that are a stunning 100-fold more active (IC50 values, 50-75 pM vs. 7 nM; HCT116), and that are now accessible because of advances in the total synthesis of the natural product. The newly discovered ultrapotent vinblastines, which may look highly unusual upon first inspection, bind tubulin with much higher affinity and likely further disrupt the tubulin head-to-tail α/β dimer-dimer interaction by virtue of the strategic placement of an added conformationally well-defined, rigid, and extended C20′ urea along the adjacent continuing protein-protein interface. In this case, the added mol. complexity was used to markedly enhance target binding and functional biol. activity (100-fold), and likely represents a general approach to improving the properties of other natural products targeting a protein-protein interaction.

Compounds in my other articles are similar to this one((S)-3-Methoxypyrrolidine)Electric Literature of C5H11NO, you can compare them to see their pros and cons in some ways,such as convenient, effective and so on.

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Pyrimidine | C4H4N2 – PubChem,
Pyrimidine – Wikipedia

Formula: C10H8ClN. The protonation of heteroatoms in aromatic heterocycles can be divided into two categories: lone pairs of electrons are in the aromatic ring conjugated system; and lone pairs of electrons do not participate. Compound: 4-Chloro-8-methylquinoline, is researched, Molecular C10H8ClN, CAS is 18436-73-2, about Hypoxia-selective antitumor agents. 6. 4-(Alkylamino)nitroquinolines: a new class of hypoxia-selective cytotoxins. Author is Denny, William A.; Atwell, Graham J.; Roberts, Peter B.; Anderson, Robert F.; Boyd, Maruta; Lock, Colin J. L.; Wilson, William R..

A series of isomeric 4-[[3-(dimethylamino)propyl]amino]nitroquinolines, e.g., I [Rn = H, 3-, 5-, 6-, 7-, 8-NO2, 2,5-Me(O2N), 3,5-Me(O2N), 6,5-Me(O2N), 8,5-Me(O2N), 7,8-Me(O2N), 7,6-Me(O2N), 2,3-Me(O2N)], has been synthesized and evaluated as hypoxia-selective cytotoxins and as radiosensitizers of hypoxic cells. The compounds showed widely-differing hypersensitivity factors (ratios of cytotoxicity against wild-type and repair-deficient mammalian cells). Many compounds showed oxygen-sensitive bioreduction resulting in DNA alkylation, while others show oxygen-insensitive modes of action. Of the nitro isomers studied, the 5-nitro showed the greatest hypoxic selectivity. A series of ring-substituted analogs were then prepared, in an effort to lower its reduction potential of -286 mV. Structure-activity studies showed that the effects of substitution on reduction potential were complex, being mediated by electronic and steric effects on the nitro group, as well as by effects on quinoline pKa. Two compounds of lower reduction potential, the 3- and 8-Me analogs, showed improved selectivity (47- and 60-fold in a clonogenic assay). These two compounds also showed the highest in vitro therapeutic indexes of the series as hypoxic cell radiosensitizers. Despite these favorable in vitro properties, neither compound had activity against hypoxic cells in SCCVII tumors when administered at 60% of the maximum tolerated dose.

Compounds in my other articles are similar to this one(4-Chloro-8-methylquinoline)Formula: C10H8ClN, you can compare them to see their pros and cons in some ways,such as convenient, effective and so on.

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Pyrimidine | C4H4N2 – PubChem,
Pyrimidine – Wikipedia

Name: 5-Methylfuran-2(3H)-one. The mechanism of aromatic electrophilic substitution of aromatic heterocycles is consistent with that of benzene. Compound: 5-Methylfuran-2(3H)-one, is researched, Molecular C5H6O2, CAS is 591-12-8, about Catalytic C-C coupling of furanic platform chemicals to high carbon fuel precursors over supported ionic liquids. Author is Gebresillase, Mahlet N.; Seo, Jeong Gil.

Imidazolium-based ionic liquid (IL) catalysts with different anions (Cl-, HSO4-, and CF3SO3-) were covalently anchored to the surface of fibrous silica (FS) by using alkyl chains as a linker. The prepared catalysts were applied for the C-C coupling reactions of 2-methylfuran (2-MF) with levulinic acid (LA), angelica lactone (AL), and Et levulinate (EL) to synthesize high carbon fuel precursors. The hydrophilic nature of FS supported IL catalyst having bisulfate anion was suitable for the self C-C coupling reaction of 2-MF and the reaction of 2-MF with LA. FS supported IL catalyst having triflate anion (FS-ILCF3SO3) exhibited high conversion and selectivity for the target fuel precursors from the C-C coupling reaction of 2-MF with AL and EL. The increased solubility, tunable acidity, and hydrophilicity/hydrophobicity of FS-ILHSO4 and FS-ILCF3SO3 promise a sustainable catalyst system. Supported ILs make the transformation processes greener and more efficient for large-scale production of biomass-derived fuel precursors.

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Pyrimidine | C4H4N2 – PubChem,
Pyrimidine – Wikipedia

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.Formula: C5H6O2.Romaniszyn, Marta; Gronowska, Katarzyna; Albrecht, Lukasz published the article 《Remote Functionalization of 4-(Alk-1-en-1-yl)-3-Cyanocoumarins via the Asymmetric Organocatalytic 1,6-Addition》 about this compound( cas:591-12-8 ) in Advanced Synthesis & Catalysis. Keywords: dihydrofuranyl ethyl oxo chromene carbonitrile preparation diastereoselective enantioselective regioselective; alkenyl cyanocoumarin furanone organocatalytic addition. Let’s learn more about this compound (cas:591-12-8).

An organocatalytic 1,6-addition using 4-(alk-1-en-1-yl)-3-cyanocoumarins as acceptors was developed. Dienolates derived from 5-substituted-furan-2(3H)-ones have been employed as pronucleophiles, therefore, enabling the synthesis of hybrid mols. bearing two biol. relevant units I [R = H, 7-MeO, 6-Br, etc.; R1 = Me, allyl, Ph, etc.; R2 = H, Me; R3 = H, Me]. Appropriate design of substrates and the application of quinine-derived catalyst resulted in very good site-selectivity as well as chem. and stereochem. efficiency of the process.

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Pyrimidine | C4H4N2 – PubChem,
Pyrimidine – Wikipedia

Safety of 5-Methylfuran-2(3H)-one. The mechanism of aromatic electrophilic substitution of aromatic heterocycles is consistent with that of benzene. Compound: 5-Methylfuran-2(3H)-one, is researched, Molecular C5H6O2, CAS is 591-12-8, about Catalytic C-C coupling of furanic platform chemicals to high carbon fuel precursors over supported ionic liquids. Author is Gebresillase, Mahlet N.; Seo, Jeong Gil.

Imidazolium-based ionic liquid (IL) catalysts with different anions (Cl-, HSO4-, and CF3SO3-) were covalently anchored to the surface of fibrous silica (FS) by using alkyl chains as a linker. The prepared catalysts were applied for the C-C coupling reactions of 2-methylfuran (2-MF) with levulinic acid (LA), angelica lactone (AL), and Et levulinate (EL) to synthesize high carbon fuel precursors. The hydrophilic nature of FS supported IL catalyst having bisulfate anion was suitable for the self C-C coupling reaction of 2-MF and the reaction of 2-MF with LA. FS supported IL catalyst having triflate anion (FS-ILCF3SO3) exhibited high conversion and selectivity for the target fuel precursors from the C-C coupling reaction of 2-MF with AL and EL. The increased solubility, tunable acidity, and hydrophilicity/hydrophobicity of FS-ILHSO4 and FS-ILCF3SO3 promise a sustainable catalyst system. Supported ILs make the transformation processes greener and more efficient for large-scale production of biomass-derived fuel precursors.

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Pyrimidine | C4H4N2 – PubChem,
Pyrimidine – Wikipedia

In general, if the atoms that make up the ring contain heteroatoms, such rings become heterocycles, and organic compounds containing heterocycles are called heterocyclic compounds. An article called Synthesis of 3-pyridinols. III. Synthesis of pyridoxine skeletons from 4-methyloxazole, published in 1965, which mentions a compound: 148-51-6, Name is 5-(hydroxymethyl)-2,4-dimethylpyridin-3-ol hydrochloride, Molecular C8H12ClNO2, Application In Synthesis of 5-(hydroxymethyl)-2,4-dimethylpyridin-3-ol hydrochloride.

Pyridoxine dimethyl ether (I) and 4-deoxypyridoxine (II) were synthesized from 4-methyloxazole (III). 3-Cyano-5-hydroxy-6-methylpyridine (IV) was converted via the 4-CN derivative (V) to pyridoxine by the method of Okamoto and Tani (CA 54, 22644d). (MeOCH2CHBr)2 (5.5 g.) refluxed 1 hr. with 1.23 g. KOH in 12 cc. MeOH gave 2.2 g. MeOCH2CBr:CHCH2OMe (VI), b12 75-8°. VI (5.5 g.) and 3.5 g. CuCN heated 7 hrs. at 150° in an autoclave yielded 2.9 g. MeOCH2CH:C(CN)CH2OMe (VII), b8 84-6°. III (0.8 g.), 2.1 g. VII, 0.2 cc. H2O, and 4 cc. AcOH heated 40 hrs. at 95°, and the crude product chromatographed on Al2O3 yielded 2-methyl-4,5-bis(methoxymethyl)-3-pyridinol-HCl (VIII.HCl), m. 143-4° (iso-PrOH); picrate m. 168°. III (0.80 g.), 2.3 g. MeCH:CHCO2Et, 0.18 cc. H2O, and 3 cc. AcOH heated 20 hrs. at 90° in a sealed tube gave 0.2 g. (crude) Et 5-hydroxy-4,6-dimethylnicotinate, m. 146-8° (Me2CO). VIII (80 mg.) in 15 cc. dry tetrahydrofuran treated 72 hrs. at room temperature with 50 mg. LiAlH4 in 15 cc. dry tetrahydrofuran, and the filtered mixture acidified to pH 2 with dilute HCl and evaporated gave II.HCl, m. 255-7° (decomposition) (EtOH). IV (4.0 g.) in 90 cc. AcOH heated 1 hr. at 100° with 6 cc. 30% H2O2, treated twice with addnl. 6 cc. 30% H2O2 each time 1 and 4 hrs. gave 3.3 g. 5hydroxy-6-methylnicotinonitrile 1-oxide (IX), m. 278-80° (decomposition). IX (0.7 g.) and 0.7 g. Et2SO4 heated 2 hrs. at 100-10° gave 0.31 g. 1-ethoxy-2-methyl-3-hydroxy-5-cyanopyridinium ethosulfate, m. 129-30°. IX (0.6 g.) and 0.55 g. Me2SO4 heated 2 hrs. at 100-10°, and the resulting sirup added in 5 cc. H2O dropwise with shaking at 5-7° to 0.65 g. KCN in 8 cc. H2O and kept 1.5 hr. at room temperature gave 0.55 g. V, m. 189-90°.

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Pyrimidine | C4H4N2 – PubChem,
Pyrimidine – Wikipedia

The reaction of an aromatic heterocycle with a proton is called a protonation. One of articles about this theory is 《Vitamin B6. II. Reactions and derivatives》. Authors are Harris, Stanton A..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.

Vitamin B6-HCl (I) in an equal mixture of C5H5N and Ac2O, allowed to stand overnight and then heated on a steam bath for 20 min., gives vitamin B6 triacetate-HCl [2-methyl-3-acetoxy-4,5-bis(acetoxymethyl)-pyridine-HCl], m. 157°; it is stable in 0.01 N HCl but is slowly hydrolyzed in 0.01 N alkali at 37°. Vitamin B6 dibromide-HBr (II) and 3 equivalents AcOAg in a 22% solution of AcOK in AcOH, heated on the steam bath for 0.5 hrs., give 25% of vitamin B6 diacetate-HCl [2-methyl-3-hydroxy-4,5-bis(acetoxymethyl) pyridine-HCl], m. 160-1°; the aqueous solution gives a good FeCl3 test; it has the same relative stability as the tri-Ac derivative Reduction of II with a PdBaSO4 catalyst in EtOH gives 40% of 2,4,5-trimethyl-3-hydroxypyridine, m. 178°; HCl salt, m. 216°. Catalytic reduction of I with the Adams catalyst gives 2,4-dimethyl-3-hydroxy-5-hydroxymethylpyridine-HCl, m. 267-8°; this is weakly active for the growth and promotion of acid formation by Streptobacterium plantarum, whereas III is inactive. I, exactly neutralized with 1 equivalent of MeONa in MeOH and heated at 125° for 4 hrs., gives a small yield of 2-methyl-3-hydroxy-4-methoxymethyl-5-hydroxymethylpyridine-HCl (III), m. 181°.

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Pyrimidine | C4H4N2 – PubChem,
Pyrimidine – Wikipedia

Khan, M. Akram; Miller, Keith; Rainsford, Kim Drummond; Zhou, Yong published the article 《Synthesis and antimicrobial activity of novel substituted ethyl 2-(quinolin-4-yl)-propanoates》. Keywords: quinolinylpropanoate preparation antimicrobial Helicobacter.They researched the compound: 4-Chloro-8-methylquinoline( cas:18436-73-2 ).Synthetic Route of C10H8ClN. Aromatic heterocyclic compounds can be divided into two categories: single heterocyclic and fused heterocyclic. In addition, there is a lot of other information about this compound (cas:18436-73-2) here.

4-Hydroxyquinolines were synthesized from anilines and EtOCH:C(CO2Et)2 by Gould-Jacobs reaction via cyclization of the intermediate (anilinomethylene)malonate followed by hydrolysis and decarboxylation. The 4-hydroxyquinolines reacted with POCl3 to form 4-chloroquinolines, which reacted on heating with Na+MeC-(CO2Et)2 in DMF to yield moderate yields of 2-(quinolin-4-yl)propanoates, many of which showed potent antimicrobial activity against Helicobacter pylori.

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Reference:
Pyrimidine | C4H4N2 – PubChem,
Pyrimidine – Wikipedia