- Can Heteroarenes/Arenes Be Hydrogenated Over Catalytic Pd/C Under Ambient Conditions?
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Hydrogenation of over a dozen aromatic compounds, including both heteroarenes and arenes, over palladium on carbon (Pd/C, 1–100 molpercent) with H2-balloon pressure at room temperature is reported. Analyses using pyridine as a model substrate revealed that acetic acid was the best solvent, as using only 1 molpercent Pd/C provided piperidine quantitatively. Substrate scope analysis and density functional theory calculations indicated that reaction rates are highly dependent on frontier molecular orbital characteristics and the steric bulkiness of substituents. Moreover, the established method was used for the concise synthesis of the anti-Alzheimer drug donepezil (Aricept?).
- Tanaka, Nao,Usuki, Toyonobu
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p. 5514 - 5522
(2020/07/24)
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- Synthesis method of cinnamyl piperazine
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The invention discloses a synthesis method of cinnamyl piperazine. The method includes the steps of: a) adding a solvent into a reaction kettle and adding piperazine to uniformly dissolve the piperazine, dropwisely adding hydrochloric acid at 20-25 DEG C until the pH of the reaction solution is 2, which is the terminal, and after the reaction is performed for 1 h, cooling the reaction solution to 20 DEG C, and centrifugally spin-filtering the reaction solution to obtain piperazine dihydrochloride; b) adding the solvent into the reaction kettle, adding the piperazine dihydrochloride and the piperazine with stirring at the same time, and performing a reaction at 68-85 DEG C for 0.5-3 h; c) reducing the temperature to 45-55 DEG C, dropwisely adding cinnamyl chloride, and then increasing the temperature to 60-75 DEG C to perform a temperature maintained reaction for 1-4 h, and reducing the temperature to 10-35 DEG C, performing centrifugal separation, sucking a mother liquid into a distillation reaction kettle, heating the distillation mother liquid to recycle the solvent, adding pure water, and dropwisely adding an alkali liquid to regulate the pH to 9-12, and adding chloroform to perform extraction, drying the mixture, and evaporate-drying the chloroform to obtain the cinnamyl piperazine. The synthesis method reduces production steps and pollutant emission, and is more suitable for modern industrial production.
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Paragraph 0016; ; 0017; 0018; 0019
(2017/08/27)
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- A convenient synthesis of 1-aralkyl-4-benzylpiperazine derivatives
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An efficient two-step route was developed for the synthesis of 1-aralkyl-4-benzylpiperazine derivatives by a Blanc reaction and alkylation. The key intermediate, N-benzylpiperazine, was prepared in an excellent yield by direct benzylation of commercially available piperazine under metal-free conditions.
- Hu, Xiao,Chen, Hui,Wu, Wei-Jun,Wang, Wen-Ling,Wang, Jin
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p. 519 - 520
(2016/10/05)
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- Substituted 1-propiolylpiperazine compounds, their preparation and use
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Substituted 1-propiolylpiperazine compounds corresponding to formula I in which X denotes N or C—R2, and n is an integer from 0 to 8, a method for producing such substituted 1-propiolylpiperazine compounds, pharmaceutical compositions containing such substituted 1-propiolylpiperazine compounds, and the use of such substituted 1-propiolylpiperazine compounds for modulating mGluR5 receptor activity or for treating or inhibiting pain and various other conditions, especially conditions at least partly mediated by the mGluR5 receptor.
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- PROCESS FOR PRODUCING PIPERAZINE DERIVATIVE
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A process for producing a compound represented by the following general formula or its salt: (1) wherein A represents a lower alkylene group; characterized by comprising reacting a single salt of piperazine represented by the following formula: (2) wherein XH represents a salt-forming organic acid or inorganic acid; with a compound represented by the following general formula: (3) wherein A has the same meaning as defined above; and Y represents an acid residue.
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Page/Page column 19
(2010/11/25)
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- Sulfonyl aryl hydroxamates and their use as matrix metalloprotease inhibitors
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This invention is directed to sulfonyl aromatic hydroxamic acid compounds and salts thereof that, inter alia, inhibit matrix metalloprotease (MMP) activity and/or aggrecanase activity. In some particularly preferred embodiments, the compound corresponds in structure to one of the following formulas: wherein W2, the R groups, and —A—R—E—Y are described in more detail in Applicants' specification. This invention also is directed to a process that comprises administering such a compound or pharmaceutically acceptable salt thereof to a host animal having a condition associated with MMP activity.
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- SULFONYL ARYL HYDROXAMATES AND THEIR USE AS MATRIX METALLOPROTEASE INHIBITORS
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This invention is directed to sulfonyl aromatic hydroxamic acid compounds and salts thereof that, inter alia, inhibit matrix metalloprotease (MMP) activity and/or aggrecanase activity. In some particularly preferred embodiments, the compound corresponds in structure to one of the following formulas: wherein W2, the R groups, and--A--R--E--Y are described in more detail in Applicants' specification. This invention also is directed to a process that comprises administering such a compound or pharmaceutically acceptable salt thereof to a host animal having a condition associated with MMP activity.
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- Use of sulfonyl aryl or heteroaryl hydroxamic acids and derivatives thereof as aggrecanase inhibitors
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This invention is directed to a process for inhibiting aggrecanase activity. The process comprises administering a therapeutically effective amount of a sulfonyl aromatic or heteroaromatic hydroxamic acid, a derivative thereof, or a pharmaceutically acceptable salt of the hydroxamic acid or derivative to a host animal. The compound generally corresponds in structure to the following formula: wherein W and the R groups are described in more detail in Applicants' specification.
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- Pyridyl-and pyrmidyl-piperazines useful for the treatment of mental disorders
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The present invention concerns novel compounds of the general formula; STR1 wherein R 1 is halogen or hydrogen and R 2 is halogen; X is either oxygen, sulfor or methyleneR 3 and R 4 are the same or different and selected from hydrogen and lower alkyl;n is 2 or 3;A is selected from the following pyrimidyl or pyridyl groups STR2 wherein R 5 is selected from hydrogen, lower alkyl or halogen; R 6 and R 7 are the same or different and selected from hydrogen, halogen, lower alkyl, electron donor groups such as lower alkoxy or hydroxy, electron acceptor groups such as cyano, nitro, trifluoromethyl, COOR 8, CONR 9 R 10 or CO-B;wherein R 8 is hydrogen or lower alkyl;R 9 and R 10 are the same or different and selected from hydrogen, lower alkyl and cycloalkyl;B is selected from STR3 wherein m is 1, 2, 3 or 4. R 11 is selected from hydrogen or lower alkyl, and the pharmacologically active salts thereof.The new compounds are useful for treating mental disorders.
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- Piperazinecarboxamides having a phenoxyalkyl or thiophenoxyalkyl side chain
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Novel compounds of formula (I), wherein R1 is selected from hydrogen, halogen; or trifluoromethyl; X is oxygen or sulfur; R2 and R3 are the same or different and selected from hydrogen or lower alkyl; m is 2 or 3; Y is oxygen or sulphur; Z is selected from: --NR4 R5, formulae (II), (III) or (IV), wherein R4 and R5 are the same or different and selected from hydrogen, alkyl, cycloalkyl, cycloalkyl-alkyl, hydroxy-alkyl, alkoxyalkyl or alkanoyloxyalkyl, phenyl or phenyl-alkyl, wherein the phenyl groups may be unsubstituted or monosubstituted with halogen or CF3 ; n is 0, 1, 2 or 3; R6 and R7 are the same or different and selected from hydrogen, lower alkyl, hydroxy, lower alkoxy or lower alkanoyloxy; p is 2 or 3; R8 and R9 are the same or different and selected from hydrogen or lower alkyl; R10 is hydrogen, lower alkyl or lower alkanoyl. The new compounds can be used for treating mental disorders.
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- Piperazine derivatives as circulation-enhancing substances
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Novel N-(trimethoxybenzyl)-piperazines of the formula: STR1 wherein R is trifluoromethyl, hydroxy, nitro, halogen, lower-alkyl, or lower-alkoxy; R' is hydrogen, trifluoromethyl, halogen, lower-alkyl, or lower-alkoxy; R" is hydrogen or lower-alkoxy, or wherein R and either R' or R" together stand for lower-alkylene dioxy, and acid addition salts thereof, a method of preparing same, pharmaceutical compositions thereof, and a method of enhancing circulation, especially cerebrovascular circulation, therewith, are disclosed.
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- N-cyclohexyl-piperazino acetamides and propionamides
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New piperazine derivatives and homologs thereof of formula STR1 wherein n is equal to 2 or 3 and m to 1, 2 or 3; X REPRESENTS HYDROGEN OR A METHYL GROUP R represents hydrogen or a C1 to C6 lower alkyl group or a C1 to C3 hydroxyalkyl group; and R1 is one of the following groups: A substituted cyclohexyl of formula STR2 wherein R2 is hydrogen or a C1 to C6 lower alkyl group, A SUBSTITUTED PHENYL OF FORMULA STR3 wheein R3 is hydrogen, methyl or ethyl, OR WHEREIN R1 is norbornyl, bornyl or cinnamyl, are useful as antiulcerous compounds.
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- Piperazino quinazoline bronchodilators
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A series of novel 4-piperazino-6,7-dialkoxyquinazolines and 1-piperazino-6,7-dialkoxyisoquinolines have been prepared, including their acid addition salts. These compounds are useful in therapy as bronchodilators and as smooth muscle relaxants. Methods for their preparation from known compounds are provided.
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