Tag: 200-300

Elucidation of the presence and location of t-Boc protecting groups in amines and dipeptides using on-column H/D exchange HPLC/ESI/MS was written by Wolf, Christian;Villalobos, Cristina N.;Cummings, Paul G.;Kennedy-Gabb, Sonya;Olsen, Mark A.;Trescher, Gudrun. And the article was included in Journal of the American Society for Mass Spectrometry in 2005.Name: tert-Butyl methyl(6-methylpyridin-2-yl)carbamate This article mentions the following:

High performance liquid chromatog./mass spectrometry (HPLC/MS) has become a widely used technique for routine anal. of pharmaceutical compounds The constant search for new drugs requires the development of time-efficient methods that can be employed in high-throughput screening of combinatorial libraries of a variety of compounds, including amines and peptides. Conventional HPLC/MS is a powerful technique that can easily be automated and is suitable for comprehensive screening purposes. However, the unequivocal determination of the presence and location of important carbamoyl protecting groups of amines is often elusive because of their inherent instability under MS conditions. In this study, the use of on-column H/D exchange HPLC/ESI/MS for structure elucidation of t-Boc protecting groups which can often not be detected by MS because of facile McLafferty rearrangement has been examined We demonstrate that employing a deuterated mobile phase in HPLC/MS anal. provides a convenient tool for the determination of the absence or presence of t-Boc protecting groups in amines and peptides. In the experiment, the researchers used many compounds, for example, tert-Butyl methyl(6-methylpyridin-2-yl)carbamate (cas: 205676-84-2Name: tert-Butyl methyl(6-methylpyridin-2-yl)carbamate).

tert-Butyl methyl(6-methylpyridin-2-yl)carbamate (cas: 205676-84-2) belongs to pyridine derivatives. Pyridines are an important class of heterocycles and occur in polysubstituted forms in many naturally occurring biologically active compounds, drug molecules and chiral ligands. Pyridine, its benzo and pyridine-based compounds play diverse roles in organic chemistry. Pyridine-based materials are valued for their optical and physical properties as well as their medical potential. Name: tert-Butyl methyl(6-methylpyridin-2-yl)carbamate

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Methoxycarbonylation of iodobenzene in ionic liquids. A case of inhibiting effect of imidazolium halides was written by Zawartka, W.;Trzeciak, A. M.;Ziolkowski, J. J.;Lis, T.;Ciunik, Z.;Pernak, J.. And the article was included in Advanced Synthesis & Catalysis in 2006.Name: 1-Butyl-4-methylpyridin-1-ium bromide This article mentions the following:

The palladium(II) complexes, PdCl₂(cod) (1), PdCl₂[P(OPh)₃]₂ (2), [bmim]₂[PdCl₄] (3), and [bmpy]₂[PdCl₄] (4) (bmim = 1-butyl-3-methylimidazolium cation, bmpy = 1-butyl-4-methylpyridinium cation), were active catalysts for the methoxycarbonylation of iodobenzene in ionic liquid (IL) media. The best results were obtained in pyridinium salts, [bmpy]X (X = Cl, Br, BF₄, PF₆) (76-100% yield). In methoxycarbonylation reactions carried out in imidazolium salts, [bmim]BF₄ and [bmim]PF₆, the yield of benzoic acid Me ester was slightly lower (50-78% yield), whereas in [bmim]X (X = Cl, Br) the reaction was totally retarded. The inhibiting effect was not observed when a Me group was present at C-2 (instead of a proton) on the imidazole ring. A palladium-carbene complex, Pd(bmimy)₂Br₂ (5), obtained in the reaction of a palladium catalyst precursor with [bmim]Cl, presented much lower activity than precursors 1–4. Its formation may explain the observed inhibition of methoxycarbonylation in a [bmim]Cl medium. The crystal structures of some of the palladium-carbene complexes were determined In the experiment, the researchers used many compounds, for example, 1-Butyl-4-methylpyridin-1-ium bromide (cas: 65350-59-6Name: 1-Butyl-4-methylpyridin-1-ium bromide).

1-Butyl-4-methylpyridin-1-ium bromide (cas: 65350-59-6) belongs to pyridine derivatives. Pyridine has a dipole moment and a weaker resonant stabilization than benzene (resonance energy 117 kJ·mol−1 in pyridine vs. 150 kJ·mol−1 in benzene). Several pyridine derivatives play important roles in biological systems. While its biosynthesis is not fully understood, nicotinic acid (vitamin B3) occurs in some bacteria, fungi, and mammals.Name: 1-Butyl-4-methylpyridin-1-ium bromide

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Efficient regioselective preparation of monobromo- and bromoiodo-hydroxypyridines from dibromo derivatives via bromine-lithium exchange was written by Meana, Angela;Rodriguez, Justo F.;Sanz-Tejedor, Ma Ascension;Garcia-Ruano, Jose L.. And the article was included in Synlett in 2003.Related Products of 13472-81-6 This article mentions the following:

Annular dibromination of hydroxypyridines with NBS followed by bromine-lithium exchange with alkyllithium and subsequent trapping with H₂O or I₂ afforded bromo(hydroxy)- and bromo(iodo)hydroxypyridines, e.g., I, in a completely regioselective way. Iodination of bromohydroxypyridines with NIS is totally regioselective. In the experiment, the researchers used many compounds, for example, 3,5-Dibromo-2-hydroxypyridine (cas: 13472-81-6Related Products of 13472-81-6).

3,5-Dibromo-2-hydroxypyridine (cas: 13472-81-6) belongs to pyridine derivatives. The pyridine ring occurs in many important compounds, including agrochemicals, pharmaceuticals, and vitamins. Pyridine groups exist in countless molecules, and their applications include catalysis, drug design, molecular recognition, and natural product synthesis.Related Products of 13472-81-6

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Four organic-inorganic compounds based on polyoxometalates: crystal structures and catalytic epoxidation of styrene was written by Wang, Chunling;Ren, Yuanhang;Feng, Sujiao;Kong, Zuping;Hu, Yichen;Yue, Bin;Deng, Mingli;He, Heyong. And the article was included in Journal of Coordination Chemistry in 2014.Related Products of 15420-02-7 This article mentions the following:

Four compounds based on polyoxometalates, [Cu(4-bpo)(H₂O)][Cu₂(μ₂-Cl)(4-bpo)₂(H₂O)][SiW₁₂O₄₀][NMe₄]₂·H₂O (1), [Cu(4-bpo)]₄[P₂W₁₈O₆₂][NMe₄]₂·6H₂O (2), [Cu₂(μ₂-OH)(4-bpo)₂(Hina)(H₂O)₂]₂[P₂W₁₈O₆₂]·4H₂O (3), and [Cu₂(Hina)₄(H₂O)₂][H₂P₂W₁₈O₆₂](Hina)·11H₂O (4) (4-bpo = 2,5-bis(4-pyridyl)-1,3,4-oxadiazole, ina = isonicotinic acid), were hydrothermally synthesized and characterized by elemental anal., IR, and single-crystal x-ray diffraction. The 3-dimensional framework of 1 is composed by Keggin-type polyoxoanions {SiW₁₂} and two types of infinite chains, {Cu(4-bpo)(H₂O)}_n and {Cu₂(μ₂-Cl)(4-bpo)₂(H₂O)}_n, through H bonds. Compound 2 has a 3-dimensional rigid framework which is fabricated by Wells-Dawson type polyoxoanions {P₂W₁₈} and Cu-(4-bpo) chains through covalent bonds. Compound 3 contains an infinite {Cu₂(μ₂-OH)(4-bpo)₂(Hina)(H₂O)₂}_n double-chain and {P₂W₁₈} polyoxoanions immobilized in the voids between the chains. Compound 4 exhibits a 3-dimensional supramol. network directed by H bonds between {P₂W₁₈} polyoxoanions and the double paddle-wheel {Cu₂(Hina)₄(H₂O)₂}. Compounds 1–4 were tested as heterogeneous catalysts for the epoxidation of styrene using tert-Bu hydroperoxide (TBHP) as oxidant. The compounds show catalytic activity with 2 giving the highest yield of styrene oxide. In the experiment, the researchers used many compounds, for example, 2,5-Di(pyridin-4-yl)-1,3,4-oxadiazole (cas: 15420-02-7Related Products of 15420-02-7).

2,5-Di(pyridin-4-yl)-1,3,4-oxadiazole (cas: 15420-02-7) belongs to pyridine derivatives. Pyridine’s the lone pair does not contribute to the aromatic system but importantly influences the chemical properties of pyridine, as it easily supports bond formation via an electrophilic attack. Pyridine derivatives are also useful as small-molecule α-helix mimetics that inhibit protein-protein interactions, as well as functionally selective GABA ligands.Related Products of 15420-02-7

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Brosted acidic pyridinium-based ILs catalyzed the selective dimerization of isobutene: Performance and in-situ NMR study was written by Yu, Xiaojia;Liu, Ying;Wang, Hui;Cheng, Weiguo;Wu, Youqing;Zhang, Suojiang. And the article was included in Molecular Catalysis in 2020.Synthetic Route of C10H16BrN This article mentions the following:

Brosted acidic pyridinium-based ILs of [NS][CF₃SO₃] and [NS][HSO₄] have been synthesized for oligomerization of isobutene with the excellent conversion of 92.8% and the good selective dimerization at the temperature of below 100°C. Hydroxyl-containing materials, especially ethanol, could facilitate catalytic activities to excellent conversions of isobutene and 84.2% selectivity of diisobutene. [NS][CF₃SO₃] could be recovered by a simple liquid-to-liquid separation and reused more than ten times without obvious loss of catalytic activities. The formation process of oligomers has been examined by in-situ NMR spectroscopy, and a step-by-step generation process of carbonium ions varying from C⁺₄, C⁺₈ to C⁺₁₂ was proposed. The work behaves the significance of constructing a better catalysis system for highly selective dimerization of isobutene, and potential being scaled-up for industrialization. In the experiment, the researchers used many compounds, for example, 1-Butyl-4-methylpyridin-1-ium bromide (cas: 65350-59-6Synthetic Route of C10H16BrN).

1-Butyl-4-methylpyridin-1-ium bromide (cas: 65350-59-6) belongs to pyridine derivatives. The ring atoms in the pyridine molecule are sp2-hybridized. The nitrogen is involved in the π-bonding aromatic system using its unhybridized p orbital. The lone pair is in an sp2 orbital, projecting outward from the ring in the same plane as the σ bonds. One of the examples of pyridines is the well-known alkaloid lithoprimidine, which is an A3 adenosine receptor antagonist and N,N-dimethylaminopyridine (DMAP) analog, commonly used in organic synthesis.Synthetic Route of C10H16BrN

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Development of an Efficient Manufacturing Process for Reversible Bruton’s Tyrosine Kinase Inhibitor GDC-0853 was written by Zhang, Haiming;Cravillion, Theresa;Lim, Ngiap-Kie;Tian, Qingping;Beaudry, Danial;Defreese, Jessica L.;Fettes, Alec;James, Philippe;Linder, David;Malhotra, Sushant;Han, Chong;Angelaud, Remy;Gosselin, Francis. And the article was included in Organic Process Research & Development in 2018.Formula: C5H3Br2NO This article mentions the following:

Efforts toward the process development of reversible Bruton’s tyrosine kinase (BTK) inhibitor GDC-0853 are described. A practical synthesis of GDC-0853 was accomplished via a key highly regioselective Pd-catalyzed C-N coupling of tricyclic lactam with 2,4-dichloronicotinaldehyde to afford the C-N coupling product, a Suzuki-Miyaura cross-coupling of intermediate with boronic ester derived from a Pd-catalyzed borylation of tetracyclic bromide, to generate penultimate aldehyde intermediate and subsequent aldehyde reduction and recrystallization Process development of starting materials is also discussed. In the experiment, the researchers used many compounds, for example, 3,5-Dibromo-2-hydroxypyridine (cas: 13472-81-6Formula: C5H3Br2NO).

3,5-Dibromo-2-hydroxypyridine (cas: 13472-81-6) belongs to pyridine derivatives. In contrast to benzene, Pyridine’s electron density is not evenly distributed over the ring, reflecting the negative inductive effect of the nitrogen atom. Several pyridine derivatives play important roles in biological systems. While its biosynthesis is not fully understood, nicotinic acid (vitamin B3) occurs in some bacteria, fungi, and mammals.Formula: C5H3Br2NO

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Communication IX. Study of the structure of 2-hydroxypyridine with electron acceptor substituents in the ring was written by Falyakhov, I. F.;Gil’manov, R. Z.;Nikitin, V. G.;Larionova, O. A.. And the article was included in Vestnik Kazanskogo Tekhnologicheskogo Universiteta in 2013.COA of Formula: C5H3Br2NO This article mentions the following:

IR spectra of a series of 2-hydroxypyridine derivatives containing electron acceptor substituents have been recorded. These data show that in the solid state the keto tautomeric form of hydroxypyridine predominates in the most cases. In the experiment, the researchers used many compounds, for example, 3,5-Dibromo-2-hydroxypyridine (cas: 13472-81-6COA of Formula: C5H3Br2NO).

3,5-Dibromo-2-hydroxypyridine (cas: 13472-81-6) belongs to pyridine derivatives. Pyridine has a dipole moment and a weaker resonant stabilization than benzene (resonance energy 117 kJ·mol−1 in pyridine vs. 150 kJ·mol−1 in benzene). Pyridine, its benzo and pyridine-based compounds play diverse roles in organic chemistry. Pyridine-based materials are valued for their optical and physical properties as well as their medical potential. COA of Formula: C5H3Br2NO

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Design, synthesis, and fungicidal evaluation of novel oxysterol binding protein inhibitors for combatting resistance associated with oxathiapiprolin was written by Li, Jian-Long;Zhou, Li-Ming;Gao, Meng-Qi;Huang, Zhong-Qiao;Liu, Xi-Li;Zhu, Xiao-Lei;Yang, Guang-Fu. And the article was included in Pesticide Biochemistry and Physiology in 2020.Recommanded Product: tert-Butyl 4-carbamothioylpiperidine-1-carboxylate This article mentions the following:

Oxathiapiprolin, the first successful oxysterol binding protein (OSBP) inhibitor for oomycete control, is regarded as an important milestone in the history of fungicide discovery. However, its interaction with OSBP remain unclear. Moreover, some plant pathogenic oomycetes have developed medium to high resistance to oxathiapiprolin. In this paper, the three-dimensional (3D) structure of OSBP from Phytophthora capsici (pcOSBP) was built, and its interaction with oxathiapiprolin was systematically investigated by integrating mol. docking, mol. dynamics simulations, and mol. mechanics Poisson-Boltzmann surface area (MM/PBSA) calculations The computational results showed that oxathiapiprolin bound to pcOSBP forms H-bonds with Leu73, Lys74, Ser69, and water mols. Then, based on its interaction with pcOSBP, oxathiapiprolin was structurally modified to discover new analogs with high fungicidal activity and a low risk of resistance. Fortunately, compound 1e was successfully designed and synthesized as the most potent candidate, and it showed a much lower resistance risk (RF < 1) against LP3-M and LP3-H in P. capsici. The present work indicated that the piperidinyl-thiazole-isoxazoline moiety is useful for further optimization. Furthermore, compound 1e could be used as a lead compound for the discovery of new OSBP inhibitors. In the experiment, the researchers used many compounds, for example, tert-Butyl 4-carbamothioylpiperidine-1-carboxylate (cas: 214834-18-1Recommanded Product: tert-Butyl 4-carbamothioylpiperidine-1-carboxylate).

tert-Butyl 4-carbamothioylpiperidine-1-carboxylate (cas: 214834-18-1) belongs to pyridine derivatives. Pyridine has a dipole moment and a weaker resonant stabilization than benzene (resonance energy 117 kJ·mol−1 in pyridine vs. 150 kJ·mol−1 in benzene). One of the examples of pyridines is the well-known alkaloid lithoprimidine, which is an A3 adenosine receptor antagonist and N,N-dimethylaminopyridine (DMAP) analog, commonly used in organic synthesis.Recommanded Product: tert-Butyl 4-carbamothioylpiperidine-1-carboxylate

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Inhibiting effects of some oxadiazole derivatives on the corrosion of mild steel in perchloric acid solution was written by Lebrini, Mounim;Bentiss, Fouad;Vezin, Herve;Lagrenee, Michel. And the article was included in Applied Surface Science in 2005.Name: 2,5-Di(pyridin-4-yl)-1,3,4-oxadiazole This article mentions the following:

The efficiency of 3,5-bis(n-pyridyl)-1,3,4-oxadiazole (n-POX, n = 1, 2, 3), as corrosion inhibitors for mild steel in 1 M perchloric acid (HClO₄) have been determined by weight loss measurements and electrochem. studies. The results show that these inhibitors revealed a good corrosion inhibition even at very low concentrations Comparison of results among those obtained by the studied oxadiazoles shows that 3-POX was the best inhibitor. Polarisation curves indicate that n-pyridyl substituted-1,3,4-oxadiazoles are mixed type inhibitors in 1 M HClO₄. The adsorption of these inhibitors follows a Langmuir isotherm model. The electronic properties of n-POX, obtained using the AM1 semi-empirical quantum chem. approach, were correlated with their exptl. efficiencies using the linear resistance model (LR). In the experiment, the researchers used many compounds, for example, 2,5-Di(pyridin-4-yl)-1,3,4-oxadiazole (cas: 15420-02-7Name: 2,5-Di(pyridin-4-yl)-1,3,4-oxadiazole).

2,5-Di(pyridin-4-yl)-1,3,4-oxadiazole (cas: 15420-02-7) belongs to pyridine derivatives. Pyridine is diamagnetic and has a diamagnetic susceptibility of −48.7 × 10−6 cm3·mol−1.The molecular electric dipole moment is 2.2 debyes. The standard enthalpy of formation is 100.2 kJ·mol−1 in the liquid phase and 140.4 kJ·mol−1 in the gas phase. Pyridine, its benzo and pyridine-based compounds play diverse roles in organic chemistry. Pyridine-based materials are valued for their optical and physical properties as well as their medical potential. Name: 2,5-Di(pyridin-4-yl)-1,3,4-oxadiazole

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Structures of substituted di-aryl-1,3,4-oxadiazole derivatives: 2,5-bis(pyridyl)- and 2,5-bis(aminophenyl)-substitution was written by Emmerling, Franziska;Orgzall, Ingo;Reck, Guenter;Schulz, Burkhard W.;Stockhause, Sabine;Schulz, Burkhard. And the article was included in Journal of Molecular Structure in 2006.Synthetic Route of C12H8N4O This article mentions the following:

Crystal structures of four different di-aryl-1,3,4-oxadiazole compounds (aryl = 2-pyridyl-, 3-pyridyl-, 2-aminophenyl-, 3-aminophenyl-) are determined Crystallization of di(2-pyridyl)-1,3,4-oxadiazole yielded monoclinic and triclinic polymorphs. The structures are characterized by the occurrence of π-π interactions. Addnl., in case of the aminophenyl compounds intra- as well as intermol. hydrogen bonds are found that influence the packing motif as well. Since these mols. are often used as ligands in metal-organic complexes similarities and differences of the mol. conformation between the mols. in the pure crystals and that of the ligands in the complexes are discussed. In the experiment, the researchers used many compounds, for example, 2,5-Di(pyridin-4-yl)-1,3,4-oxadiazole (cas: 15420-02-7Synthetic Route of C12H8N4O).

2,5-Di(pyridin-4-yl)-1,3,4-oxadiazole (cas: 15420-02-7) belongs to pyridine derivatives. Pyridine has a conjugated system of six π electrons that are delocalized over the ring. The molecule is planar and, thus, follows the Hückel criteria for aromatic systems. Several pyridine derivatives play important roles in biological systems. While its biosynthesis is not fully understood, nicotinic acid (vitamin B3) occurs in some bacteria, fungi, and mammals.Synthetic Route of C12H8N4O

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem