- Oxidative Ring-Opening of 1H-Pyrazol-5-amines and Its Application in Constructing Pyrazolo–Pyrrolo–Pyrazine Scaffolds by Domino Cyclization
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Herein, an oxidative ring-opening of 1H-pyrazol-5-amines to form 3-diazenylacrylonitrile derivatives under mild and transition-metal-free conditions is described. In addition, the nucleophilic addition of deprotonated 1H-pyrrole-2-carbaldehydes to the vinyl moiety of the yielded 3-diazenylacrylonitriles could trigger domino cyclization to afford the 3H-pyrazolo[3,4-e]pyrrolo[1,2-a]pyrazine derivatives. Computational studies suggest that the oxidation of 1H-pyrazol-5-amines in the presence of PhIO is through the formation of a hydroxylamine intermediate followed by elimination of H2O to result in the ring-opening product. The detailed domino cyclization pathway leading to the pyrazolo–pyrrolo–pyrazine scaffolds is revealed.
- Bao, Xiaoguang,Fu, Rui,Gao, Ke,Jin, Feng,Pan, Lei,Zhou, Shaofang
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supporting information
p. 2956 - 2961
(2020/05/16)
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- Synthesis of chiral nopinane annelated 3-methyl-1-aryl-1H-pyrazolo[3,4-b]pyridines by condensation of pinocarvone oxime with 1-aryl-1H-pyrazol-5-amines
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Chiral 1H-pyrazolo[3,4-b]pyridines fused with nopinane frame were obtained by FeCl3-catalyzed assembling of pinocarvone oxime and 1-aryl-1H-pyrazol-5-amines. Chemical structures of new compounds were solved by NMR spectroscopy and confirmed by quantum chemical calculations and X-ray crystallography.
- Ustimenko, Yulia P.,Agafontsev, Alexander M.,Komarov, Vladislav Yu.,Tkachev, Alexey V.
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p. 584 - 586
(2018/12/13)
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- 2-(1-HETEROARYLPIPERAZIN-4-YL)METHYL-1,4-BENZODIOXANE DERIVATIVES AS ALPHA2C ANTAGONISTS
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Compounds of formula I (formula I), wherein A is an optionally substituted five-membered unsaturated heterocyclic ring containing 1, 2 or 3 N, O or S ring heteroatom(s) exhibit alpha2C antagonistic activity and are thus useful for the treatment of diseases or conditions of the peripheric or central nervous system.
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Page/Page column 68; 69
(2016/12/22)
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- Approach to the library of fused pyridine-4-carboxylic acids by combes-type reaction of acyl pyruvates and electron-rich amino heterocycles
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A library of fused pyridine-4-carboxylic acids (including pyrazolo[3,4-b]pyridines, isoxazolo[5,4-b]pyridines, furo[2,3-b]pyridines, thieno[2,3-b]pyridines, and pyrido[2,3-d]pyrimidines) was generated by Combes-type reaction of acyl pyruvates and electron-rich amino heterocycles followed by hydrolysis of the ester. The library members were also demonstrated to undergo the standard combinatorial transformations including amide coupling and esterification, as well as less common heterocyclizations to 1,2,4-triazoles and 1,2,4-oxadiazoles.
- Volochnyuk, Dmitriy M.,Ryabukhin, Sergey V.,Plaskon, Andrey S.,Dmytriv, Yuri V.,Grygorenko, Oleksandr O.,Mykhailiuk, Pavel K.,Krotko, Dmitriy G.,Pushechnikov, Alexei,Tolmachev, Andrey A.
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scheme or table
p. 510 - 517
(2010/09/05)
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- HSP INDUCTOR
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An agent for inducing HSP, comprising a compound represented by the formula (I): ???wherein R1 is a hydrogen atom, a hydrocarbon group which may be substituted, etc.; R2 is absent, a hydrogen atom or a hydrocarbon group which maybe substituted; R3 is a heterocyclic group which may be substituted; X, Y and Z are, respectively, a hydrogen, a halogen, a nitrile, a hydrocarbon group which may be substituted, or X and Y may bind to each other to form ring A, or Y and Z may bind to each other to form ring B; bond portions indicated by a solid line and a broken line are, respectively, a single bond or a double bond, and bond portions indicated by a broken line are, respectively, a single bond or absent; ring A is a homocyclic or heterocyclic 5- to 7-membered ring which may be substituted; ring B is a homocyclic or heterocyclic 5- to 7-membered ring which may be substituted; and n is an integer of 0 or 1, or a salt thereof;
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- Condensed pyrazole derivatives, process for producing the same and use thereof
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Novel pharmaceutical compositions for inhibiting Th2-selective immune response and pharmaceutical compositions for inhibiting cyclooxygenase comprising condensed pyrazole derivatives represented by the general formula (I): or salts thereof.
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- Diazepine antiallergy agents
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Platelet activating factor antagonists of formula (I), (II) or (III): STR1 where A is optionally substituted benzene, pyridine, naphthalene, quinoline, thiophene, benzothiophene, pyrazole or isothiazole, X is O, S or NH Y is 1,4 phenylene or a group of formula STR2 R1 is H or optionally substituted C1 -C4 alkyl, R2 and R3 are H or C1 -C4 alkyl, B is an optionally fused 5- or 6-membered ring containing nitrogen atoms, Het is an optionally substituted 5-membered heterocyclic ring containing nitrogen or a pyridine ring, the ring optionally being fused to benzene or nitrogen-containing heterocyclic ring.
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