3673-79-8Relevant academic research and scientific papers
A 1H NMR and molecular modelling investigation of diastereotopic methylene hydrogen atoms
Tormena, Claudio F.,Freitas, Matheus P.,Rittner, Roberto,Abraham, Raymond J.
, p. 279 - 283 (2002)
The 1H NMR spectra of methyl 3-bromo-2-methylpropionate (1a) and the corresponding chloro compound (2a) show no long-range coupling between the methyl and methylene protons. In contrast, in the analogous dihalocompounds, methyl 2,3-dibromo-2-methylpropionate (1b) and methyl 2,3-dichloro-2-methylpropionate (2b), one of the methylene protons exhibits a large 4JHH coupling (0.8 Hz) to the methyl group, but the other proton shows no observable splitting. This can be explained quantitatively by calculations of the conformational preferences in these compounds combined with the known orientation dependence of the 4JHH couplings. One conformer predominates in the dihalo compounds 1b and 2b, and this is responsible for the 4JHH coupling. In 1a and 2a all three conformers are populated and the 4JHH couplings average to zero. The technique is a potentially general method of unambiguously assigning diastereotopic methylene protons. Copyright
Photoinduced Fe-Based Atom Transfer Radical Polymerization in the Absence of Additional Ligands, Reducing Agents, and Radical Initiators
Pan, Xiangcheng,Malhotra, Nikhil,Zhang, Jianan,Matyjaszewski, Krzysztof
, p. 6948 - 6954 (2015)
A photoinduced atom transfer radical polymerization (ATRP) of methacrylate with a Fe-based catalytic system was studied in the absence of additional ligands, reducing agents, and radical initiators. Linear semilogarithmic polymerization kinetics and narrow molecular weight distributions were obtained in the presence but also absence of conventional ATRP initiators. The proposed mechanism involves monomer-mediated photoreduction of Fe(III) to Fe(II) but also photoactivation of Fe(II) species. The polymerization was studied with different radiation sources for several methacrylates. The technique was successfully used to synthesize block copolymers, confirming the living nature of ATRP.
A paraquat emetic and preparation method
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Paragraph 0018-0040; 0042, (2019/04/04)
The invention relates to the field of organic synthetic technology, in particular to a paraquat emetic and preparation method, comprises the following preparation steps, S1, preparation of [...]; S2, the preparation of the etherification; S3, pyrimidine triazole; S4, PP796 preparation. The invention one-pot method for directly simple high yield of synthetic method is more suitable for industrial production technology, the process route and is simple, low cost, production and operation method is simple and convenient, high yield, the total yield to methacrylic acid methyl ester idea can reach 43.5% or more, the obtained product and luster is pure white, crystalline state is good, content ≥ 99%.
A preparation method of the emetic (by machine translation)
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Paragraph 0026; 0031; 0036; 0042; 0047; 0051; 0052; 0058, (2019/04/17)
The invention relates to the field of organic synthetic technology, in particular to a emetic preparation method, comprises the following steps: S1, 3 - methoxy methyl acrylic acid methyl ester preparation; S2, synthesis of [...]; S3, is the synthesis of third zuo; S4, and aldehyde; S5, closed-loop. This invention adopts the single melamine as the synthetic starting material, greatly reducing the cost, dicyandiamide as to effectively solve the problem of lack of raw material sources; solved in the prior art long reaction time, the reaction condition is sensitive, harsh, side reaction are numerous and complex, the use of expensive or difficult to prepare sodium of other reagents, reactions caused low overall yield, the product quality is poor, so that the synthesis process technology of the route is more stable, good reproducibility, high yield, the product quality is good, content can be up to 99.5%, the yield can reach 85.6%, has higher economic benefits. (by machine translation)
Technology for three-innovation synthesis of 2-amino-5-methyl-4-oxo-3-n-propyltriazolopyrimidine
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Paragraph 0015; 0029-0040, (2019/11/29)
The invention discloses a technology for synthesizing 2-amino-5-methyl-4-oxo-3-n-propyl-6H-triazolo-[1,5-a]pyrimidine. Methyl methacrylate and bromine are firstly subjected to an addition reaction toprepare methyl 2,3-dibromo-2-methylpropanoate, and then the methyl 2,3-dibromo-2-methylpropanoate and sodium methylate are etherified in a new suitable solvent to prepare methyl 3,3-dimethoxy-2-methylpropionate etherate; the etherate and 3,5-diamino-1,2,4-triazole, prepared from hydrazine hydrate and dicyandiamide under the catalysis of an acid, are condensed at an intermediate temperature of about 115 DEG C under the catalysis of an organic base to obtain a pyrimidotriazole compound; and the pyrimidotriazole material liquid and 1-chloropropane undergo a direct alkylation reaction in an inorganic or organic bas and a new solvent to obtain the 2-amino-5-methyl-4-oxo-3-n-propyl-6H-triazolo-[1,5-a]pyrimidine. The technology is improved by the three major innovations of improving the catalyticsynthesis conditions of the condensation ring closure of the pyrimidotriazole, optimizing the alkylation substitution reaction and the process technology of the pyrimidinetriazole and innovating theraw material of an alkylation reagent, so the technology has the advantages of great improvement of the yield, simplicity in operation, mild reaction conditions, and safety to devices and human bodies, the total yield of methyl methacrylate can reach 46.5% or above, and the obtained product has a white color and a good crystalline state, and has a content of 99% or more.
Discovery of a novel series of pyrazolo[1,5-a]pyrimidine-based phosphodiesterase 2A inhibitors structurally different from N-((1S)-1-(3-fluoro-4-(trifluoromethoxy)phenyl)-2-methoxyethyl)-7-methoxy-2-oxo-2,3-dihydropyrido[2,3-b]pyrazine-4(1H)-carboxamide (TAK-915), for the treatment of cognitive disorders
Mikami, Satoshi,Kawasaki, Masanori,Ikeda, Shuhei,Negoro, Nobuyuki,Nakamura, Shinji,Nomura, Izumi,Ashizawa, Tomoko,Kokubo, Hironori,Hoffman, Isaac Dylan,Zou, Hua,Oki, Hideyuki,Uchiyama, Noriko,Hiura, Yuuto,Miyamoto, Maki,Itou, Yuuki,Nakashima, Masato,Iwashita, Hiroki,Taniguchi, Takahiko
, p. 1058 - 1077 (2017/11/17)
It has been hypothesized that selective inhibition of phosphodiesterase (PDE) 2A could potentially be a novel approach to treat cognitive impairment in neuropsychiatric and neurodegenerative disorders through augmentation of cyclic nucleotide signaling pathways in brain regions associated with learning and memory. Following our earlier work, this article describes a drug design strategy for a new series of lead compounds structurally distinct from our clinical candidate 2 (TAK-915), and subsequent medicinal chemistry efforts to optimize potency, selectivity over other PDE families, and other preclinical properties including in vitro phototoxicity and in vivo rat plasma clearance. These efforts resulted in the discovery of N-((1S)-2-hydroxy-2-methyl-1-(4-(trifluoromethoxy)phenyl)propyl)-6-methyl-5-(3-methyl-1H-1,2,4triazol-1-yl)pyrazolo[1,5-a]pyrimidine-3-carboxamide (20), which robustly increased 3′,5′-cyclic guanosine monophosphate (cGMP) levels in the rat brain following an oral dose, and moreover, attenuated MK-801-induced episodic memory deficits in a passive avoidance task in rats. These data provide further support to the potential therapeutic utility of PDE2A inhibitors in enhancing cognitive performance.
HETEROCYCLIC COMPOUND
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Paragraph 1444; 1658, (2016/06/28)
A compound represented by the formula (I): wherein each symbol is as described in the SPECIFICATION, or a salt thereof has a PDE2A inhibitory action, and is useful as a prophylactic or therapeutic drug for schizophrenia, Alzheimer's disease and the like.
Heterocyclic compound
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Paragraph 0183, (2017/02/24)
A compound represented by the formula (I): wherein each symbol is as described in the SPECIFICATION, or a salt thereof has a PDE2A inhibitory action, and is useful as a prophylactic or therapeutic drug for schizophrenia, Alzheimer’s disease and the like.
Highly enantioselective Rh-Catalyzed Alkenylation of imines: Synthesis of Chiral Allylic Amines via Asymmetric addition of Potassium Alkenyltrifluoroborates to N-Tosyl imines
Gopula, Balraj,Chiang, Chien-Wei,Lee, Way-Zen,Kuo, Ting-Shen,Wu, Ping-Yu,Henschke, Julian P.,Wu, Hsyueh-Liang
supporting information, p. 632 - 635 (2014/04/03)
For the first time, simple N-tosyl aryl aldimines, prepared from the condensation of tosyl amide and aromatic aldehydes, can be used as substrates in the rhodium catalyzed 1,2- addition reaction using alkenylboron nucleophiles. In the presence of 1.5 mol % of [RhCl(1e)]2, enantioselective addition of various potassium alkenyltrifluoroborates to aryl aldimines furnished the corresponding chiral allylic amines in 73-96% yield and 72->99.5% ee. Notably, this method efficiently provides the di-, tri-, and tetrasubstituted allylic N-tosyl amines with high asymmetric induction.
Catalytic enantioselective nazarov cyclization: Construction of vicinal all-carbon-atom quaternary stereocenters
Jolit, Anais,Walleser, Patrick M.,Yap, Glenn P. A.,Tius, Marcus A.
supporting information, p. 6180 - 6183 (2014/06/23)
The diastereoselective asymmetric synthesis of vicinal all-carbon-atom quaternary stereocenters is a challenging problem in organic synthesis for which only few solutions have been described. A catalytic asymmetric Nazarov cyclization of fully substituted dienones that provides cyclopentenone derivatives with vicinal quaternary stereocenters in high optical purity and as single diastereoisomers is now reported.
