Tag: M.W=200-250

den Hertog, H. J. published the artcileHetarynes. VI. Amination of bromoethoxypyridines, SDS of cas: 17117-13-4, the main research area is .

cf. CA 58, 11325a; 60, 1724d. Some bromoethoxypyridines were aminated with KNH2 in liquid NH3. The 3-bromo- and 4-bromoethoxypyridines reacted via hetaryne intermediates. The reaction of 2-bromo-6-ethoxypyridine proceeded via a rearrangement. 2-Bromo-4-ethoxypyridine, b2 104-6°, m. 35-6°, was prepared by treating 2-bromo-4-hydroxypyridine with diazoethane in Et2O for 16 hrs. at room temperature 4-Bromo-2-ethoxypyridine, m. 5.5-7°, was prepared from 4-amino-2-ethoxypyridine. Amination was carried out by adding 2.5 millimoles of the bromoethoxypyridine in Et2O to a solution prepared from 10 millimoles K and 30-40 ml. liquid NH3 in the presence of Fe(NO3)3 at -33° over a period of 10 min. (with stirring). The reaction-was stopped with 12 millimoles NH4Cl and the mixture evaporated, extracted with Et2O, and analyzed by gas chromatography. The following results were obtained [bromoethoxypyridine used and the aminoethoxypyridine(s) (molar ratio) produced given]: 4-bromo-2-ethoxy, 3-amino-2-ethoxy[-(1-2%)], 4-amino-2-ethoxy[-(98-99%)]; 4-bromo-3-ethoxy, 5-amino-3-ethoxy; 3-bromo-2-ethoxy, 3-amino-2-ethoxy (3), 4-amino-2-ethoxy (97); 3-bromo-4-ethoxy, 2-amino-4-ethoxy (55-60), 2-amino-5-bromo-4-ethoxy (15-20), 4-ethoxy (25); 3-bromo-5-ethoxy, 3-amino-5-ethoxy; 3-bromo-6-ethoxy, 3-amino-6-ethoxy (35), 4-amino-6-ethoxy (65); 2-bromo-3-ethoxy, 2-amino-3-ethoxy (99), 3-ethoxy (1); 2-bromo-4-ethoxy, 2-amino-4-ethoxy; 2-bromo-5-ethoxy, 2-amino-5-ethoxy (90-95), 5-ethoxy (5-10); 2-bromo-6-ethoxy, 2-amino-6-ethoxy (80-85), 4-amino-6-ethoxy (10-15).

Recueil des Travaux Chimiques des Pays-Bas published new progress about Amination. 17117-13-4 belongs to class pyridine-derivatives, name is 2-Bromo-4-ethoxypyridine, and the molecular formula is C7H8BrNO, SDS of cas: 17117-13-4.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Croitoru, M. D. published the artcileDirect HPLC-UV determination of cyclemate, saccharine and aspartame from soft drinks, Recommanded Product: Ethyl 4-hydroxy-6-oxo-6,7-dihydrothieno[2,3-b]pyridine-5-carboxylate, the main research area is cyclamate saccharine aspartame soft drink HPLC UV detection.

Artificial sweeteners were introduced in therapy as sugar substitutes for diabetic patients. Nowadays these substances are widely used for sugar substitution in low calorie drinks and sweets. Most commonly used products to date are saccharine, cyclamate, aspartame, and acesulfam; maximum accepted daily intakes are stated for each one. A simple reverse phase (RP18) HPLC-UV method with direct detection (196 nm) was developed by us in order to measure the concentrations of the three sweeteners. No sample preparation is required, other than dilution Limits of detection are 12 mg l-1, 0.5 mg l-1 and lower than 0.25 mg l-1 for cyclamate, aspartame and saccharine, resp. Concentrations ranged between 113.14-280.07 mg l-1 in the case of cyclamate, 17.96-50.94 mg l-1 for saccharine, and 9.94-296.82 mg l-1 for aspartame.

Acta Alimentaria published new progress about Beverages. 99429-68-2 belongs to class pyridine-derivatives, name is Ethyl 4-hydroxy-6-oxo-6,7-dihydrothieno[2,3-b]pyridine-5-carboxylate, and the molecular formula is C10H9NO4S, Recommanded Product: Ethyl 4-hydroxy-6-oxo-6,7-dihydrothieno[2,3-b]pyridine-5-carboxylate.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Schmidt, Michael A. published the artcileEffect of Terminal Alkylation of Aryl and Heteroaryl Hydrazines in the Fischer Indole Synthesis, Computed Properties of 3469-63-4, the main research area is Fischer indole synthesis; hydrazine ketone alkylation amidation cross coupling.

The effect of alkylation on the terminal position of aryl and heteroaryl hydrazines in the Fischer indole synthesis was examined Compared to their unalkylated counterparts, reactions using alkylated s provided indole products with higher yields and faster rates. The reactions can be conducted at lower temperatures and are compatible with acid-sensitive functionality. The terminally alkylated hydrazines were readily prepared by a new two-step sequence and held as stable hydrazinium salts. The mild formation of the salts along with the favorable Fischer indole reaction conditions highlights the potential of this approach in later-stage synthetic use.

Journal of Organic Chemistry published new progress about Alkylation. 3469-63-4 belongs to class pyridine-derivatives, name is Ethyl 5-methoxy-1H-pyrrolo[2,3-c]pyridine-2-carboxylate, and the molecular formula is C11H12N2O3, Computed Properties of 3469-63-4.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Swanson, Devin M. published the artcileIdentification and biological evaluation of 4-(3-trifluoromethylpyridin-2-yl)piperazine-1-carboxylic acid (5-trifluoromethylpyridin-2-yl)amide, a high affinity TRPV1 (VR1) vanilloid receptor antagonist, Computed Properties of 306934-70-3, the main research area is vanilloid receptor antagonist preparation analgesic.

High throughput screening using the recombinant human TRPV1 receptor was used to identify a series of pyridinylpiperazine ureas as TRPV1 vanilloid receptor ligands. Exploration of the structure-activity relationships by parallel synthesis identified the essential pharmacophoric elements for antagonism that permitted further optimization via targeted synthesis to provide a potent orally bioavailable and selective TRPV1 modulator 41 active in several in vivo models.

Journal of Medicinal Chemistry published new progress about Analgesics. 306934-70-3 belongs to class pyridine-derivatives, name is 1-(5-(Trifluoromethyl)pyridin-2-yl)-1,4-diazepane, and the molecular formula is C11H14F3N3, Computed Properties of 306934-70-3.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Barker, John M. published the artcileThienopyridines. Part 7. Some electrophilic substitution reactions of thieno[2,3-b]- and -[3,2-b]pyridine isosteres of 4-oxygenated and 2,4-dioxygenated quinolines, Product Details of C10H9NO4S, the main research area is electrophilic substitution thienopyridine regiochem; quinolinone isostere electrophilic substitution.

Electrophilic substitution reactions were examined of the title compounds I, II [X = NMe, X1 = CO (III); X = CO, X1 = NH (IV), NMe (V)], VI, and VII. The 4-quinolone analogs I and IV, like the parent compound, were monobrominated and (diethylamino)methylated in the pyridine ring α to the CO group. However, whereas 4-quinolone and IV were nitrated in the pyridine ring by HNO3 alone, I was nitrated mainly in the thiophene ring at C-2 under these conditions. The methylated compounds III and V showed a similar regiochem. to their nonmethylated analogs, although their reactivity was lower. I and II were dinitrated by mixed HNO3-H2SO4 at the position α to the CO group in the pyridine ring and at either C-2 in the [2,3-b] isomers (I and III) or C-3 in the [3,2-b] compounds (IV and V); dibromination of I, III, and IV followed a similar pattern. Mannich reactions of VI and VII occurred in the pyridine rings, whereas bromination occurred in the thiophene and pyridine rings in VI and VII, resp.

Journal of Chemical Research, Synopses published new progress about Bromination. 99429-68-2 belongs to class pyridine-derivatives, name is Ethyl 4-hydroxy-6-oxo-6,7-dihydrothieno[2,3-b]pyridine-5-carboxylate, and the molecular formula is C10H9NO4S, Product Details of C10H9NO4S.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Saielli, Giacomo published the artcileOne-bond ¹J(¹⁵N-¹⁹F) spin-spin coupling constants of cationic fluorinating reagents: Insights from DFT calculations, Product Details of C6H5F4NO3S, the publication is Magnetic Resonance in Chemistry (2020), 58(6), 548-558, database is CAplus and MEDLINE.

We have investigated, by means of d. functional theory protocols, the one-bond ¹J(¹⁵N-¹⁹F) spin-spin coupling constants in a series of fluorinating reagents, containing the N-F bond, recently studied exptl. The results of the calculations show a very good linear relationship with the exptl. values, even though only the M06-2X(PCM)/pcJ-2//B3LYP/6-311G(d,p) level affords a very low mean absolute error. The calculations allow to analyze the various MOs contributions to the J coupling and to rationalize the observed pos. sign, corresponding to a neg. sign of the reduced spin-pin coupling constant K(N-F). Moreover, of the four Ramsey contributions, only the diamagnetic spin orbit is negligible, whereas the paramagnetic spin orbit and spin dipole terms decrease the magnitude of the Fermi contact (FC) term by an amount that goes from a min. of 35% up to more than 60% of the FC term itself. Several effects have been investigated, namely, the contribution of the long-range solvent reaction field, relativistic corrections, and conformational and vibrational effects.

Magnetic Resonance in Chemistry published new progress about 107263-95-6. 107263-95-6 belongs to pyridine-derivatives, auxiliary class Fluorination reagent, name is 1-Fluoropyridiniumtriflate, and the molecular formula is C6H5F4NO3S, Product Details of C6H5F4NO3S.

Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem

Li, Xing published the artcileNewly-generated Al(OH)₃-supported Pd nanoparticles-catalyzed Stille and Kumada coupling reactions of diazonium salts, (Het)aryl chlorides, Quality Control of 89076-64-2, the publication is Tetrahedron (2016), 72(1), 69-75, database is CAplus.

A ligand-free Pd/Al(OH)₃ nano-catalyst which is prepared by one-pot three-component method using Pd(PPh₃)₄, tetra (ethylene glycol), and aluminum tri-sec-butoxide exhibits excellent catalytic activity in Stille cross-couplings of (Het)aryl chlorides, arenediazonium tetrafluoroborate salts with phenyltributylstannane, resp., and Kumada couplings of (Het)aryl chlorides with various Grignard reagents. More importantly, these two processes show excellent functional group compatibility with moderate to good yields and they are also versatile with respect to not only (Het)aryl chlorides, but also diazonium salts, and heteroaryl Grignard reagents. The nano-catalyst could also be recycled and reused 5 times without loss of activity and decrease of yield.

Tetrahedron published new progress about 89076-64-2. 89076-64-2 belongs to pyridine-derivatives, auxiliary class Pyridine,Nitro Compound,Benzene, name is 5-Nitro-2-phenylpyridine, and the molecular formula is C11H8N2O2, Quality Control of 89076-64-2.

Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem

Asahara, Haruyasu published the artcileSubstituent Diversity-directed Synthesis of Nitropyridines and Nitroanilines by Three-component Ring Transformation, Quality Control of 89076-64-2, the publication is Procedia Engineering (2017), 1046-1057, database is CAplus.

A novel method for synthesis of various kinds of nitroarenes by using a three-component ring transformation (TCRT) of dinitropyridone with ketones in the presence of ammonium acetate as nitrogen source is developed. This method requires only simple manipulations and mild reaction conditions. Furthermore, the modification of obtained nitropyridine or nitroaniline frameworks can be easily obtained only changing a com. available substrates.

Procedia Engineering published new progress about 89076-64-2. 89076-64-2 belongs to pyridine-derivatives, auxiliary class Pyridine,Nitro Compound,Benzene, name is 5-Nitro-2-phenylpyridine, and the molecular formula is C11H8N2O2, Quality Control of 89076-64-2.

Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem

El-Assal, Mona Ibrahim published the artcileNano-sponge novel drug delivery system as carrier of anti-hypertensive drug, Computed Properties of 89076-64-2, the publication is International Journal of Pharmacy and Pharmaceutical Sciences (2019), 11(10), 47-63, database is CAplus.

The study was designed to prepare Nano-sponge formulation loaded with nifedipine. Studying parameters which affecting the formulas in addition to pharmacokinetics and toxicity tests. Nine Nano-sponge formulations were prepared by the solvent evaporation technique. Different ratios of polymer ethylcellulose, COpolymers β-cyclodextrin and hydroxypropyl β-cyclodextrin in addition to solubilizing agent polyvinyl alc. were used. Thermal anal., X-ray powder diffraction (XRPD), shape and surface morphol., particle size, %production yield, %porosity, % swelling, and % drug entrapment efficiency of Nano-sponge were examined Release kinetic also studied beside comparison of pharmacokinetic parameters of the optimum choice formula and marketed one in addition to Toxicol. consideration. Particle size in the range of 119.1 nm to 529 nm which were increased due to the increase in the concentration of polymer to the drug. Nano-sponge revealed porous, spherical nature. Increased in the drug/polymer molar ratios (1:1 to 1:3) may increase their % production yield ranged from 62.1% to 92.4%. The drug content of different formulations was in the range of 77.9% to 94.7%, and entrapment efficiency was in the range of 82.72 % to 96.63%. Drug released in controlled sustained pattern and followed Higuchi, s diffusion mechanism. Pharmacokinetic parameters of optimized formula showed significant higher maximum plasma drug concentration, area under plasma concentration-time curve, volume of distribution and mean residence time. Nano-sponge loaded drug proved biol. safety at low concentrations Nano-sponge drug delivery system has showed small Nano size, porous with controlled drug release and significant-high plasma drug concentration that improved solubility, drug bioavailability and proved safety.

International Journal of Pharmacy and Pharmaceutical Sciences published new progress about 89076-64-2. 89076-64-2 belongs to pyridine-derivatives, auxiliary class Pyridine,Nitro Compound,Benzene, name is 5-Nitro-2-phenylpyridine, and the molecular formula is C11H8N2O2, Computed Properties of 89076-64-2.

Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem

Kiselyov, Alexander S. published the artcileA novel three-component reaction of N-fluoropyridinium salts: a facile approach to imidazo[1,2-a]pyridines, Formula: C6H5F4NO3S, the publication is Tetrahedron Letters (2005), 46(26), 4487-4490, database is CAplus.

The reaction of N-fluoropyridinium triflates I (R¹ = H, 2-Me, 4-Me₂CH, 2-Ph, 3-Cl, etc.) with isonitriles R²NC (R² = Me₂CH, Me₃C, EtO₂CH₂, cyclohexyl, Ph, PhCH₂, etc.) in acetonitrile or propionitrile in the presence of NaBH(OAc)₃ led to the formation of the corresponding imidazo[1,2-a]pyridines II (R³ = Me, Et) in 44-73% yields. The proposed reaction mechanism involves the intermediate formation of a highly reactive carbene species and apparent reduction of the pyridinium intermediate with NaBH(OAc)₃ to yield the targeted heterocycles.

Tetrahedron Letters published new progress about 107263-95-6. 107263-95-6 belongs to pyridine-derivatives, auxiliary class Fluorination reagent, name is 1-Fluoropyridiniumtriflate, and the molecular formula is C6H5F4NO3S, Formula: C6H5F4NO3S.

Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem