- An ATR-FTIR study on the effect of molecular structural variations on the CO2 absorption characteristics of heterocyclic amines, part II
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This paper reports on an ATR-FTIR spectroscopic investigation of the CO2 absorption characteristics of a series of heterocyclic diamines: hexahydropyrimidine (HHPY), 2-methyl and 2,2-dimethylhexahydropyrimidine (MHHPY and DMHHPY), hexahydropyridazine (HHPZ), piperazine (PZ) and 2,5- and 2,6-dimethylpiperazine (2,6-DMPZ and 2,5-DMPZ). By using in situ ATR-FTIR the structure-activity relationship of the reaction between heterocyclic diamines and CO2 is probed. PZ forms a hydrolysis-resistant carbamate derivative, while HHPY forms a more labile carbamate species with increased susceptibility to hydrolysis, particularly at higher CO2 loadings (>0.5 mol CO2/mol amine). HHPY exhibits similar reactivity toward CO2 to PZ, but with improved aqueous solubility. The α-methyl-substituted MHHPY favours HCO3- formation, but MHHPY exhibits comparable CO2 absorption capacity to conventional amines MEA and DEA. MHHPY show improved reactivity compared to the conventional α-methyl- substituted primary amine 2-amino-2-methyl-1-propanol. DMHHPY is representative of blended amine systems, and its reactivity highlights the advantages of such systems. HHPZ is relatively unreactive towards CO 2. The CO2 absorption capacity CA (mol CO 2/mol amine) and initial rates of absorption RIA (mol CO2/mol amine min-1) for each reactive diamine are determined: PZ: CA=0.92, RIA=0.045; 2,6-DMPZ: C A=0.86, RIA=0.025; 2,5-DMPZ: CA=0.88, R IA=0.018; HHPY: CA=0.85, RIA=0.032; MHHPY: CA=0.86, RIA=0.018; DMHHPY: CA=1.1, R IA=0.032; and HHPZ: no reaction. Calculations at the B3LYP/6-31+G* and MP2/6-31+G* calculations show that the substitution patterns of the heterocyclic diamines affect carbamate stability, which influences hydrolysis rates. Copyright
- Robinson, Kelly,McCluskey, Adam,Attalla, Moetaz I.
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- PYRAZOLE DERIVATIVES
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A compound represented by formula (I): (wherein Ar1 represents a phenyl group which may have 1 to 3 substituents, or a non-substituted 5- or 6-membered aromatic heterocyclic group; Ar2 represents (i) a non-substituted phenyl group, (ii) a phenyl group which has been substituted by a lower alkyl group having 1 to 3 groups or atoms selected from among a carbamoyl group, an amino group, a hydroxyl group, a lower alkoxy group, and a halogen atom, or (iii) a 5- or 6-membered nitrogen-containing aromatic heterocyclic group which has been substituted by 1 to 3 groups or atoms selected from among a lower alkyl group, a lower alkynyl group, a lower alkanoyl group, a carbamoyl group, a cyano group, an amino group, a hydroxyl group, a lower alkoxy group, and a halogen atom; and X represents a group represented by formula (II): (wherein the ring structure represents a 4- to 7-membered heterocyclic group which may have, in addition to the nitrogen atom shown in formula (II), one heteroatom selected from among nitrogen, oxygen, and sulfur, and which may be substituted by 1 to 4 groups or atoms selected from among a lower alkyl group, a carbamoyl group, an amino group, a hydroxyl group, a lower alkoxy group, an oxo group, a lower alkanoyl group, a lower alkylsulfonyl group, and a halogen atom)), a salt thereof, a solvate of the compound or the salt, and a drug.
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Page/Page column 35
(2010/11/26)
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- PYRAZOLE DERIVATIVE
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A compound represented by Formula (I): wherein Ar1 represents Formula (II): Ar2 represents a 5- or 6-membered aromatic heterocyclic group which may be substituted; and X represents Formula (III): a salt thereof, or a solvate of the compound or the salt. A potent platelet aggregation suppressant which does not inhibit COX-1 and COX-2 is provided.
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Page/Page column 42
(2010/11/27)
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- Synthesis, molecular modeling and biological evaluation of aza-proline and aza-pipecolic derivatives as FKBP12 ligands and their in vivo neuroprotective effects
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Nonimmunosuppressant ligands, exemplified by GPI 1046 (1), for the peptidyl-prolyl isomerase FKBP12 have been found to unexpectedly possess powerful neuroprotective and neuroregenerative effects in vitro and in vivo. We have extensively explored the thera
- Wilkinson, Douglas E.,Thomas IV, Bert E.,Limburg, David C.,Holmes, Agnes,Sauer, Hansjorg,Ross, Douglas T.,Soni, Raj,Chen, Yi,Guo, Hong,Howorth, Pamela,Valentine, Heather,Spicer, Dawn,Fuller, Mike,Steiner, Joseph P.,Hamilton, Gregory S.,Wu, Yong-Qian
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p. 4815 - 4825
(2007/10/03)
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- Aza compounds, pharmaceutical compositions and methods of use
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The present invention relates to N-substituted cyclic aza compounds, pharmaceutical compositions comprising such compounds, and methods of their use for effecting neuronal activities.
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- Azapeptide acids as cell adhesion inhibitors
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Azapeptide acids of Formula I are antagonists of VLA-4 and/or alpha 4 beta 7, and as such are useful in the inhibition or prevention of cell adhesion and cell-adhesion mediated pathologies. These compounds may be formulated into pharmaceutical composition
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- Process for producing cyclic hydrazine derivatives, tetra-hydropyridazine and hexahydropyridazine
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The present invention relates to a process for producing alicyclic hydrazine derivatives, tetrahydropyridazine and hexahydropyridazine which are useful as intermediate starting materials such as medicines and agricultural chemicals. Especially, the present invention provides; a process for producing an alicyclic hydrazine derivative or its hydrohalogenic acid salt, which comprises reacting a hydrazine hydrohalogenic acid salt with a diol compound or an alicyclic ether compound in the presence of an excessive inorganic acid existing in a free form or in the form of an acid addition salt; a process for producing tetrahydropyridazine from 1-aminopyrrolidine, which comprises oxidizing 1-aminopyrrolidine with an oxidizing agent to form tetrahydropyridazine; and a process for producing hexahydropyridazine, which comprises oxidizing 1-aminopyrrolidine with an oxidizing agent, synthesizing tetrahydropyridazine, and thereafter, hydrogenating the tetrahydropyridazine in the presence of a base.
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- Process for producing hexahydropyridazine and hexahydropyridazine-1,2-dicarboxy derivative
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The present invention provides a process for producing a hexahydropyridazine-1,2-dicarboxy derivative represented by the general formula: STR1 wherein R1 and R2 represent each independently an alkyl group, by reacting a hydrazinedicarboxy derivative represented by the general formula: wherein R1 and R2 have the same meaning as mentioned above, with a dihalogenobutane represented by the general formula: wherein X1 and X2 represent each independently a halogen atom, in the presence of an alkali metal hydroxide, characterized in that the above reaction is effected in an aprotic polar solvent, and a process for producing a hexahydropyridazine, characterized by decarboxylating the thus obtained hexahydropyridazine-1,2-dicarboxy derivative (3) without isolation in the presence of an alkali metal hydroxide and a hydrogen-denoting compound.
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- Process for producing a hexahydropyridazine-1,2-dicarboxy derivative
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An industrial process which is a process for producing a hexahydropyridazine-1,2-dicarboxy derivative in good yield, is provided. By reacting a hydrazine dicarboxy derivative of the general formula (1): (wherein R is an alkoxy group or an aryl group) with a dihalogenobutane of the general formula (2): (wherein X is a chlorine or bromine atom) in the presence of a base selected from an alkali metal carbonate or hydroxide, a hexahydropyridazine-1,2-dicarboxy derivative represented by the general formula: STR1 (wherein R has the same meaning as R in the above general formula (1)) is obtained efficiently.
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- Synthesis and Thermal Decomposition of cis-3,4,5,6-Tetrahydropyridazine-3,4-d2. Relative Rates of Rotation, Cleavage, and Closure for Tetramethylene
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The stereospecific syntheses of cis-3,4,5,6-tetrahydropyridazine-3,4-d2 (6) and cis- and trans-cyclobutane-1,2-d2 are reported.The thermal decomposition of cis-3,4,5,6-tetrahydopyridazine (6) (gas phase, 439 deg C) affords 67.1 +/- 0.9percent cis-ethylene-1,2-d2, 16.1 +/- 0.8percent trans-ethylene-1,2-d2, 9.4 +/- 0.4percent cis-cyclobutane-1,2-d2, and 7.4 +/- 0.4percent trans-cyclobutane-1,2-d2.The relative rates of rotation, cleavage, and closure for this 1,2-diazene generated tetramethylene-d2 are k(cleavage)/k(closure) = 2.2 +/- 0.2 and k(rotation)/k(closure) = 12 +/- 3.An extra stereospecific cleavage component (46percent) superimposed on the 1,4-biradical pathway (54percent) from the parent tetrahydropyridazine was found, similar to that observed in the 3,4-dimethyl-3,4,5,6-tetrahydropyridazine thermal reactions.Finally, the experimental data fot the parent 1,4 biradical, tetramethylene, are compared to calculated values in the literature.
- Dervan, Peter B.,Santilli, Donald S.
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p. 3863 - 3870
(2007/10/02)
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