Month: October 2022

Application In Synthesis of 3,5,6-Trichloropicolinic acidOn March 30, 2010, Ma, Chun An; Li, Mei Chao; Liu, Yan Na; Xu, Ying Hua published an article in Electrochimica Acta. The article was 《In situ FTIR studies on the electrochemical hydrodechlorination of 3,4,5,6-tetrachloropicolinic acid on Ag cathode》. The article mentions the following:

The electrochem. hydrodechlorination reaction from starting material 3,4,5,6-tetrachloropicolinic acid (3,4,5,6-TCP) to the end product 3,6-dichloropicolinic acid (3,6-DCP) was studied by cyclic voltammetry and in situ FTIR spectroscopy (in situ FTIR). Compared with Cu and glassy C, Ag cathode showed a high electrocatalytic activity for the irreversible reduction process of 3,4,5,6-TCP in NaOH aqueous solution In situ FTIR results suggested that electrochem. hydrodechlorination took place in the 4- or 5-position of 3,4,5,6-TCP on Ag cathode after receiving an electron to get mixed trichloropicolinic acid free radical, which could receive another electron and give 3,5,6-trichloropicolinic acid (3,5,6-TCP) and 3,4,6-trichloropicolinic acid (3,4,6-TCP) at the potential more pos. than -1000 mV afterwards. Finally, 3,5,6-TCP and 3,4,6-TCP were further dechlorinated to produce 3,6-dichloropicolinic acid (3,6-DCP) at the potential more neg. than -1000 mV. Further studies of preparative electrolysis experiments by constant current electrolysis were carried out. The results were in good agreement with those from in situ FTIR studies. In the experimental materials used by the author, we found 3,5,6-Trichloropicolinic acid(cas: 40360-44-9Application In Synthesis of 3,5,6-Trichloropicolinic acid)

3,5,6-Trichloropicolinic acid(cas: 40360-44-9) belongs to pyridine. Pyridine, its benzo and pyridine-based compounds play diverse roles in organic chemistry. As ligands, solvents, and catalysts they facilitate reactions; thus descriptions of these new ligands and their applications abound each year.Application In Synthesis of 3,5,6-Trichloropicolinic acid

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Safety of 2,6-Bis((4S,5S)-4,5-diphenyl-4,5-dihydrooxazol-2-yl)pyridineOn October 11, 2007 ,《Dipole-LUMO/Dipolarophile-HOMO Controlled Asymmetric Cycloadditions of Carbonyl Ylides Catalyzed by Chiral Lewis Acids》 was published in Organic Letters. The article was written by Suga, Hiroyuki; Ishimoto, Daisuke; Higuchi, Satoshi; Ohtsuka, Motoo; Arikawa, Tadashi; Tsuchida, Teruko; Kakehi, Akikazu; Baba, Toshihide. The article contains the following contents:

We have found the first successful example of reverse-electron-demand dipole-LUMO/dipolarophile-HOMO controlled cycloaddition reactions between carbonyl ylides, which were generated from o-methoxycarbonyl-α-diazoacetophenone and their acyl derivatives as precursors, and vinyl ether derivatives with high levels of asym. induction (97-77% ee) using chiral 2,6-(oxazolinyl)pyridine-Eu(III) or binaphthyldiimine-Ni(II) complexes as chiral Lewis acid catalysts. In addition to this study using 2,6-Bis((4S,5S)-4,5-diphenyl-4,5-dihydrooxazol-2-yl)pyridine, there are many other studies that have used 2,6-Bis((4S,5S)-4,5-diphenyl-4,5-dihydrooxazol-2-yl)pyridine(cas: 410092-98-7Safety of 2,6-Bis((4S,5S)-4,5-diphenyl-4,5-dihydrooxazol-2-yl)pyridine) was used in this study.

2,6-Bis((4S,5S)-4,5-diphenyl-4,5-dihydrooxazol-2-yl)pyridine(cas: 410092-98-7) 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. Safety of 2,6-Bis((4S,5S)-4,5-diphenyl-4,5-dihydrooxazol-2-yl)pyridine Pyridine has a conjugated system of six π electrons that are delocalized over the ring.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Desimoni, Giovanni; Faita, Giuseppe; Filippone, Salvatore; Mella, Mariella; Zampori, Maria Grazia; Zema, Michele published their research in Tetrahedron on December 17 ,2001. The article was titled 《A new and highly efficient catalyst for the enantioselective Mukaiyama-Michael reaction between (E)-3-crotonoyl-1,3-oxazolidin-2-one and 2-trimethylsilyloxyfuran》.Name: 2,6-Bis((4S,5S)-4,5-diphenyl-4,5-dihydrooxazol-2-yl)pyridine The article contains the following contents:

The Mukaiyama-Michael reaction between 2-trimethylsilyloxyfuran and (E)-3-crotonoyl-1,3-oxazolidin-2-one has been stereoselectively catalyzed by several optically active complexes based on bis(oxazoline) (box) or pyridine bis(oxazoline) (pybox) chiral ligands and metal cations. The catalysts derived from the newly synthesized 2,6-bis[(4’R,5’R)-diphenyl-1,3-oxazolin-2′-yl]pyridine (I) and the triflates of EuIII, LaIII, CeIV were highly efficient: the diastereoselectivity was entirely anti and the enantioselectivity was excellent (ranging from 98 to >99%). A mechanistic insight into the nature of the activated substrate-catalyst complex was inferred studying the lanthanum complexes with 1H and 13C NMR spectroscopy. Based on these results and on the crystallog. structure of the complex between pybox and La(OTf)3, a stereochem. model is proposed to rationalize the crucial role of the substituent in position 5, suitably placed to blind the Si-face of the coordinated reagent. The results came from multiple reactions, including the reaction of 2,6-Bis((4S,5S)-4,5-diphenyl-4,5-dihydrooxazol-2-yl)pyridine(cas: 410092-98-7Name: 2,6-Bis((4S,5S)-4,5-diphenyl-4,5-dihydrooxazol-2-yl)pyridine)

2,6-Bis((4S,5S)-4,5-diphenyl-4,5-dihydrooxazol-2-yl)pyridine(cas: 410092-98-7) 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. Name: 2,6-Bis((4S,5S)-4,5-diphenyl-4,5-dihydrooxazol-2-yl)pyridine Pyridine has a conjugated system of six π electrons that are delocalized over the ring.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Gurak, John A. Jr.; Tran, Van T.; Sroda, Miranda M.; Engle, Keary M. published an article in Tetrahedron. The title of the article was 《N-alkylation of 2-pyridone derivatives via palladium(II)-catalyzed directed alkene hydroamination》.Product Details of 627501-18-2 The author mentioned the following in the article:

A selective N-alkylation reaction of 2-pyridones and related heterocycles via intermol. alkene hydroamination is reported. The reaction utilizes palladium(II) acetate as a catalyst and employs a bidentate directing group to dictate the regioselectivity for both unactivated terminal and internal alkenes. High functional group tolerance is observed across a wide range of electronically diverse 2-pyridones and other aza-heterocycles, including 1-hydroxyisoquinoline, 2-hydroxyquinoline, pyridazinone, pyrimidinone, and pyrazinone to obtain the corresponding products, e.g., I (X-ray single crystal structure shown). After reading the article, we found that the author used 5-Chloro-6-hydroxynicotinaldehyde(cas: 627501-18-2Product Details of 627501-18-2)

5-Chloro-6-hydroxynicotinaldehyde(cas: 627501-18-2) belongs to pyridine. Pyridine, its benzo and pyridine-based compounds play diverse roles in organic chemistry. As ligands, solvents, and catalysts they facilitate reactions; thus descriptions of these new ligands and their applications abound each year.Product Details of 627501-18-2

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

In 1954,Chemische Berichte included an article by Heyns, Kurt; Vogelsang, Gerhard. Application of 857433-67-1. The article was titled 《γ-Pyrones and γ-pyridones. I. The constitution of the hydroxy-γ-pyrones and hydroxy-γ-pyridones》. The information in the text is summarized as follows:

Methylation of kojic acid (I) according to Campbell, et al. (C.A. 44, 4468h), gives 54-65% 5-methoxy-2-hydroxymethyl-4-pyrone (II), m. 165°. Treating 25 g. II in 125 cc. concentrated HNO3 (d. 1.41) 70-80 hrs. at 20° with 25 cc. HNO3 (d. 1.52) and pouring the mixture onto 150 g. ice and 750 cc. H2O give 5-methoxy-4-pyrone-2-carboxylic acid (III), m. 282°, also obtained in 2-g. yield when a strong current of air is passed through 8 g. II in 500 cc. H2O containing 10 g. 10% Pd-C catalyst 30 hrs. at 65° and the pH is adjusted from time to time to 5-6. Heating II with concentrated NH4OH in a pressure bottle gives 75-87% 5-methoxy-2-hydroxymethyl-4-pyridone, m. 173-4°, oxidized with concentrated and fuming HNO3 (5:1) to 70-85% 5-methoxy-4-pyridone-2-carboxylic acid, m. 265°, which, heated with SOCl2, gives 94.5% 4-chloro-5-methoxy-2-pyridine-carbonyl chloride (IV), purified by sublimation in vacuo. Saponification of 39 g. IV in H2O in the presence of a little NaOH gives the free acid (V), m. 209° (Me ester, m. 166-7°). Reduction of 10 g. V in 150 cc. 10% HCl with 10 g. Sn and a small amount of HgCl2 several days at 20°, evaporation of the filtered solution, and precipitation of the Sn with H2S give 81.2% 5-methoxy-2-pyridinecarboxylic acid-HCl (VI), m. 202-3°. Refluxing 4 g. VI with 20 cc. 70% HI 3 hrs., diluting the mixture with 20 cc. H2O, decolorizing it with Na2SO3, and adjusting the pH to 3-4 give 51.2% 5-hydroxy-2-pyridinecarboxylic acid, also obtained in 92-5% yield when 7.5 g. 2-carboxy-5-pyridinesulfonic acid (VII) is heated 1 hr. at 220° with 30 g. NaOH and 6 cc. H2O in a Ni crucible and the solution of the melt in 300 cc. H2O is adjusted to pH 4-5 (Me ester, prepared with MeOH and HCl, m. 191-2°). Heating 80 g. 2-picoline in 400 g. 27% oleum in the presence of 2.5 g. HgCl2 at 220-30° gives 40% 2-methyl-5-pyridinesulfonic acid (VIII), m. above 280°. Adding (1 hr.) 126 g. KMnO4 to 63 g. Na salt of VIII in 1 l. gently boiling H2O gives 46.1% VII, m. 287° (decomposition). The compounds are identified by paper chromatography with BuOH-AcOH-H2O (180:20:50), which gives the following Rf values: III 0.26, I 0.80, 5-hydroxy-4-pyrone-2-carboxylic acid 0.27, 5-hydroxy-2-hydroxymethyl-4-pyridone 0.71, and 5-hydroxy-4-pyridone-2-carboxylic acid 0.30 (0.04% bromocresol green in 50% EtOH and 0.1% FeCl3 solution as developers). The position of the 5-OH group in the pyrone and pyridone derivatives obtained from meconic acid and from I is confirmed (cf. Belonossov, C.A. 45, 5650g). In the experiment, the researchers used Methyl 4-chloro-5-methoxypicolinate(cas: 857433-67-1Application of 857433-67-1)

Methyl 4-chloro-5-methoxypicolinate(cas: 857433-67-1) belongs to pyridine. Pyridine, its benzo and pyridine-based compounds play diverse roles in organic chemistry. As ligands, solvents, and catalysts they facilitate reactions; thus descriptions of these new ligands and their applications abound each year.Application of 857433-67-1

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Li, Xin; Cun, Lin-Feng; Gong, Liu-Zhu; Mi, Ai-Qiao; Jiang, Yao-Zhong published their research in Tetrahedron: Asymmetry on December 12 ,2003. The article was titled 《The enantioselective diethylzinc addition to imines catalyzed by chiral Cu(II)-oxazoline complexes》.Reference of 2,6-Bis((4S,5S)-4,5-diphenyl-4,5-dihydrooxazol-2-yl)pyridine The article contains the following contents:

A series of copper complexes of chiral bisoxazolines has been applied in the catalytic diethylzinc addition to N-sulfonyl imines. It has been found that the tridentate ligands,.e.g., I, provided higher enantioselectivity than bidentate ones. Addition of 4 A mol. sieves to the reaction system benefits the enantioselectivity. The optimal procedure for diethylzinc addition to different imines resulted in moderate yields and enantioselectivities of up to 82% ee. In the experiment, the researchers used many compounds, for example, 2,6-Bis((4S,5S)-4,5-diphenyl-4,5-dihydrooxazol-2-yl)pyridine(cas: 410092-98-7Reference of 2,6-Bis((4S,5S)-4,5-diphenyl-4,5-dihydrooxazol-2-yl)pyridine)

2,6-Bis((4S,5S)-4,5-diphenyl-4,5-dihydrooxazol-2-yl)pyridine(cas: 410092-98-7) 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. Reference of 2,6-Bis((4S,5S)-4,5-diphenyl-4,5-dihydrooxazol-2-yl)pyridine Pyridine has a conjugated system of six π electrons that are delocalized over the ring.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

The author of 《Design and Activity of Novel Oxadiazole Based Compounds That Target Poly(ADP-ribose) Polymerase》 were Vishwanath, Divakar; Girimanchanaika, Swamy S.; Dukanya, Dukanya; Rangappa, Shobith; Yang, Ji-Rui; Pandey, Vijay; Lobie, Peter E.; Basappa, Basappa. And the article was published in Molecules in 2022. Name: (6-Chloro-5-methylpyridin-3-yl)boronic acid The author mentioned the following in the article:

Novel PARP inhibitors with selective mode-of-action have been approved for clin. use. Herein, oxadiazole based ligands that are predicted to target PARP-1 have been synthesized and screened for the loss of cell viability in mammary carcinoma cells, wherein seven compounds were observed to possess significant IC50 values in the range of 1.4 to 25 μM. Furthermore, compound 5u, inhibited the viability of MCF-7 cells with an IC50 value of 1.4μM, when compared to Olaparib (IC50 = 3.2 μM). Compound 5s also decreased cell viability in MCF-7 and MDA-MB-231 cells with IC50 values of 15.3 and 19.2 μM, resp. Treatment of MCF-7 cells with compounds 5u and 5s produced PARP cleavage, H2AX phosphorylation and CASPASE-3 activation comparable to that observed with Olaparib. Compounds 5u and 5s also decreased foci-formation and 3D Matrigel growth of MCF-7 cells equivalent to or greater than that observed with Olaparib. Finally, in silico anal. demonstrated binding of compound 5s towardsthe catalytic site of PARP-1, indicating that these novel oxadiazoles synthesized herein may serve as exemplars for the development of new therapeutics in cancer. In the part of experimental materials, we found many familiar compounds, such as (6-Chloro-5-methylpyridin-3-yl)boronic acid(cas: 1003043-40-0Name: (6-Chloro-5-methylpyridin-3-yl)boronic acid)

(6-Chloro-5-methylpyridin-3-yl)boronic acid(cas: 1003043-40-0) belongs to pyridine. Pyridine, its benzo and pyridine-based compounds play diverse roles in organic chemistry. As ligands, solvents, and catalysts they facilitate reactions; thus descriptions of these new ligands and their applications abound each year.Name: (6-Chloro-5-methylpyridin-3-yl)boronic acid

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Xu, Yinghua; Ding, Xufen; Ma, Hongxing; Chu, Youqun; Ma, Chunan published an article in Electrochimica Acta. The title of the article was 《Selective hydrodechlorination of 3,5,6-trichloropicolinic acid at an activated silver cathode: Synthesis of 3,5-dichloropicolinic acid》.Related Products of 40360-44-9 The author mentioned the following in the article:

Electrochem. reduction of 3,5,6-trichloropicolinic acid (3,5,6-T) at glassy carbon, Ni, Cu, and Ag cathodes in aqueous solutions at different pH values was studied. Probably the selectivity of the reduction strongly depends on the cathode materials used and the pH of the aqueous solutions A high selectivity for the hydrodechlorination of 3,5,6-T to 3,5-dichloropicolinic acid (3,5-D) was achieved exclusively at an activated Ag cathode and at pH 3: a selectivity of 95% at 42% conversion under potentiostatic mode and a selectivity of 89% at 88% conversion under intentiostatic mode. An explanation is proposed for this high selectivity. After reading the article, we found that the author used 3,5,6-Trichloropicolinic acid(cas: 40360-44-9Related Products of 40360-44-9)

3,5,6-Trichloropicolinic acid(cas: 40360-44-9) belongs to pyridine. Pyridine, its benzo and pyridine-based compounds play diverse roles in organic chemistry. As ligands, solvents, and catalysts they facilitate reactions; thus descriptions of these new ligands and their applications abound each year.Related Products of 40360-44-9

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

In 2009,Xiao, Fangliang; Liu, Yu; Hu, Zhengyong; Gan, Quan; Wang, Lei; Wen, Zhonglin; Zhu, Meixiang; Zhu, Weiguo published 《Synthesis of bicyclometalated iridium complex containing 1,3,4-oxadiazole-based picolinic acid derivative and its optoelectronic properties in polymer light-emitting devices》.Synthetic Metals published the findings.Formula: C7H6BrNO2 The information in the text is summarized as follows:

A picolinic acid (Pic) derivative I bearing a 1,3,4-oxadiazole unit and its bicyclometalated iridium complex (PhOXD)2Ir(BuPhOXD-Pic) were synthesized and characterized, in which BuPhOXD-Pic (I) is 5-(4′-(5”-(4-tert-butylphenyl)-1”,3”,4”-oxadiazol-2”-yl) phenyl) picolinic acid and PhOXD is 2,5-diphenyl-1,3,4-oxadiazole. The optoelectronic properties of this iridium complex were studied in the double-layer polymer light-emitting devices using a blend of poly (9,9-dioctylfluorene) and 5-biphenyl-2-(4-tert-butyl) phenyl-1,3,4-oxadiazole as a host matrix. This complex exhibited a maximum luminance efficiency of 7.7 cd/A at 5.6 mA/cm2 and a peak brightness of 5288 cd/m2 at 153.7 mA/cm2 in the devices. Compared to the (PhOXD)2Ir(Pic) complex, the (PhOXD)2Ir(BuPhOXD-Pic) complex displays better optoelectronic properties in the devices. This study provides a convenient way to improve the optoelectronic properties of iridium complexes by modifying an ancillary ligand of picolinic acid with an 1,3,4-oxadiazole unit. The experimental process involved the reaction of Methyl 5-bromopicolinate(cas: 29682-15-3Formula: C7H6BrNO2)

Methyl 5-bromopicolinate(cas: 29682-15-3) belongs to pyridine. When pyridine is adsorbed on oxide surfaces or in porous materials, the following species are commonly observed: (i) pyridine coordinated to Lewis acid sites, (ii) pyridine H-bonded to weakly acidic hydroxyls, and (iii) protonated pyridine. At high coverage, physisorbed pyridine and protonated dimers can also be observed.Formula: C7H6BrNO2

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

In 2017,Isley, Nicholas A.; Wang, Ye; Gallou, Fabrice; Handa, Sachin; Aue, Donald H.; Lipshutz, Bruce H. published 《A Micellar Catalysis Strategy for Suzuki-Miyaura Cross-Couplings of 2-Pyridyl MIDA Boronates: No Copper, in Water, Very Mild Conditions》.ACS Catalysis published the findings.Recommanded Product: 53939-30-3 The information in the text is summarized as follows:

Suzuki-Miyaura cross-coupling of 2-pyridyl N-methyliminodiacetic acid (MIDA) boronates with aryl chlorides and bromides was carried out in the complete absence of copper by attenuation of the Lewis basicity associated with the pyridyl nitrogen using selected substituents (e.g., fluorine or chlorine) on the ring. Coupling of substituted 2-pyridinyl MIDA boronates was performed using Pd(dtbpf)Cl2 as catalyst and DIPEA in an aqueous micellar suspension of the surfactant TPGS-750-M. Dehalogenation of the halopyridines using Ni(OAc)2 and 1,10-phenanthroline as catalysts and pyridine and NaBH4, Suzuki-Miyaura coupling with aryl or heteroaryl bromides in the absence of addnl. palladium catalyst, or nucleophilic aromatic substitution of the halopyridines with dimethylamine or morpholine yielded substituted pyridines. Computational data suggest that the major role played by electron-withdrawing substituents in promoting Suzuki-Miyaura cross-couplings of 2-pyridinyl MIDA boronates in the absence of copper is to slow the rate of protodeboronation of the intermediate 2-pyridylboronic acids. 2-Pyridinylboronic acids were generated by controlled release of 2-pyridinyl MIDA boronates in D2O and underwent protodeboronation slowly under those conditions. After reading the article, we found that the author used 5-Bromo-2-chloropyridine(cas: 53939-30-3Recommanded Product: 53939-30-3)

5-Bromo-2-chloropyridine(cas: 53939-30-3) belongs to pyridine. Pyridines form stable salts with strong acids. Pyridine itself is often used to neutralize acid formed in a reaction and as a basic solvent. Recommanded Product: 53939-30-3

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem