- Calculation of hydrolytic rate constants of poly(ortho ester)s from molecular weights determined by gel permeation chromatography
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Purpose. To obtained rate constants from weight-averaged (M(w)) or z-averaged (M(z)) molecular weights for polymers of Schule-Flory distribution and undergoing random scission. These constants were compared with those obtained by parallel 1HNMR studies. Methods. The hydrolysis of two poly(ortho ester)s were followed by 1HNMR and gel permeation chromatography (GPC). Results. Equations to convert number-averaged (M(n)), M(w) and M(z) into fraction of backbone remaining (f(c)) were derived. First-order hydrolytic rate constants of two poly(ortho ester)s; DETOSU-HD and DETOSU-CDM were calculated using these relationships. The rate constants calculated from 1HNMR, M(z) and M(w) were 0.215, 0.218 and 0.182 hr-1, respectively, for DETOSU-CDM and 0.152, 0.086 and 0.038 hr-1 for DETOSU-HD. The large discrepancy in the rates determined by 1HNMR and GPC in the latter case was attributed to that the detector response (refractive index) of the monomers was lower than that of the high molecular weight polymer. The difference is small in the case of DETOSU-CDM, and the rates calculated from GPC data were comparable or nearly identical to that obtained from 1HNMR data. Conclusions. Although GPC can yield rapid and valuable kinetic data for the degradation of biodegradable polymers, the system, however, must be carefully calibrated to account for the variations in Mark-Houwink coefficients and in the response of the mass detector between the high and low MW polymers.
- Shih
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Read Online
- Production of Copolyester Monomers from Plant-Based Acrylate and Acetaldehyde
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PCTA is an important copolyester that has been widely used in our daily necessities. Currently, its monomers are industrially produced from petroleum-derived xylene. To reduce the reliance on fossil energy, we herein disclose an alternative route to acces
- Yuan, Lin,Hu, Yancheng,Zhao, Zhitong,Li, Guangyi,Wang, Aiqin,Cong, Yu,Wang, Feng,Zhang, Tao,Li, Ning
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supporting information
(2021/12/14)
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- DEOXYNOJIRIMYCIN DERIVATIVES AS GLUCOSIDASE INHIBITORS
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The present invention relates to novel iminosugars and their use as glucosidase inhibitors. The present inventors discovered that certain deoxynojirimycin derivatives may be effective in inhibiting glucosidases. In particular, such deoxynojirimycin derivatives may be useful for treating a disease or condition in which inhibition of glucosidase may play an important role.
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- Guanidine Derivatives: How Simple Structural Modification of Histamine H3R Antagonists Has Led to the Discovery of Potent Muscarinic M2R/M4R Antagonists
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This article describes the discovery of novel potent muscarinic receptor antagonists identified during a search for more active histamine H3 receptor (H3R) ligands. The idea was to replace the flexible seven methylene linker with a semirigid 1,4-cyclohexylene or p-phenylene substituted group of the previously described histamine H3R antagonists ADS1017 and ADS1020. These simple structural modifications of the histamine H3R antagonist led to the emergence of additional pharmacological effects, some of which unexpectedly showed strong antagonist potency at muscarinic receptors. This paper reports the routes of synthesis and pharmacological characterization of guanidine derivatives, a novel chemotype of muscarinic receptor antagonists binding to the human muscarinic M2 and M4 receptors (hM2R and hM4R, respectively) in nanomolar concentration ranges. The affinities of the newly synthesized ADS10227 (1-{4-{4-{[4-(phenoxymethyl)cyclohexyl]methyl}piperazin-1-yl}but-1-yl}-1-(benzyl)guanidine) at hM2R and hM4R were 2.8 nM and 5.1 nM, respectively.
- Staszewski, Marek,Nelic, Dominik,Jończyk, Jakub,Dubiel, Mariam,Frank, Annika,Stark, Holger,Bajda, Marek,Jakubik, Jan,Walczyński, Krzysztof
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p. 2503 - 2519
(2021/06/30)
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- Synthesis of 1,4-Cyclohexanedimethanol, 1,4-Cyclohexanedicarboxylic Acid and 1,2-Cyclohexanedicarboxylates from Formaldehyde, Crotonaldehyde and Acrylate/Fumarate
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Valuable polyester monomers and plasticizers—1,4-cyclohexanedimethanol (CHDM), 1,4-cyclohexanedicarboxylic acid (CHDA), and 1,2-cyclohexanedicarboxylates—have been prepared by a new strategy. The synthetic processes involve a proline-catalyzed formal [3+1+2] cycloaddition of formaldehyde, crotonaldehyde, and acrylate (or fumarate). CHDM is produced after a subsequent hydrogenation step over a commercially available Cu/Zn/Al catalyst and a one-pot hydrogenation/oxidation/hydrolysis process yields CHDA, whereas 1,2-cyclohexanedicarboxylate is obtained by a Pd/C-catalyzed tandem decarbonylation/hydrogenation step.
- Hu, Yancheng,Zhao, Zhitong,Liu, Yanting,Li, Guangyi,Wang, Aiqin,Cong, Yu,Zhang, Tao,Wang, Feng,Li, Ning
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supporting information
p. 6901 - 6905
(2018/06/04)
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- PREPARATION METHOD OF CYCLOHEXANEDIMETHANOL
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The present invention relates to a method for producing cyclohexanedimethanol. According to the present invention, trans isomers of cyclohexanedimethanol can be dominantly produced. To this end, the method for producing cyclohexanedimethanol comprises the step of performing hydrogenation of dialkyl cyclohexane dicarboxylate in which a ratio of trans isomers is 30 to 99 mole%.(AA) Feed material(BB) Reactor(CC) Separator(D1,D2) HydrogenCOPYRIGHT KIPO 2017
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Paragraph 0037; 0042-0043; 0053
(2017/12/01)
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- Synthesis and pharmacological characterization of novel N-(trans-4-(2-(4-(benzo[d]isothiazol-3-yl)piperazin-1-yl)ethyl)cyclohexyl)amides as potential multireceptor atypical antipsychotics
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A series of novel benzisothiazolylpiperazine derivatives combining potent dopamine D2and D3, and serotonin 5-HT1Aand 5-HT2Areceptor properties were synthesized and evaluated for their potential antipsychotic properties. The most-promising derivative was 9j. The unique pharmacological features of 9j were a high affinity for D2, D3, 5-HT1A, and 5-HT2Areceptors, together with a 20-fold selectivity for the D3versus D2subtype, and a low affinity for muscarinic M1(reducing the risk of anticholinergic side effects), and for hERG channels (reducing incidence of QT interval prolongation). In animal behavioral models, 9j inhibited the locomotor-stimulating effects of phencyclidine, blocked conditioned avoidance response, and improved the cognitive deficit in the novel object recognition tests in rats. 9j exhibited a low potential for catalepsy, consistent with results with risperidone. In addition, favorable brain penetration of 9j in rats was detected. These studies have demonstrated that 9j is a potential atypical antipsychotic candidate.
- Chen, Xiao-Wen,Sun, Yuan-Yuan,Fu, Lei,Li, Jian-Qi
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p. 332 - 353
(2016/08/04)
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- Low-pressure synthesis of cyclohexanedimethanol and derivatives
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The invention is directed to a process for preparing a 1,4-disubstituted cyclohexane compound of formula (I): where A is —OH, —OR, Br, or Cl; and R is a silyl group, a hydrocarbyl group, or an acyl group having 1 to 12 carbon atoms. The process includes the steps of reacting ethylene with a (2E,4E)-hexa-2,4-diene compound to produce a 3,6-disubstituted cyclohex-1-ene compound, and hydrogenating the 3,6-disubstituted cyclohex-1-ene compound to yield the 1,4-disubstituted cyclohexane compound of formula (I).
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- Mild and selective deprotection of tert -butyl(dimethyl)silyl ethers with catalytic amounts of sodium tetrachloroaurate(III) dihydrate
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A simple and mild method for the removal of tert-butyl(dimethyl)silyl (TBS) protecting groups with catalytic amounts of sodium tetrachloroaurate(III) dihydrate is described. The procedure permits selective deprotection of aliphatic TBS ethers in good to excellent yields in the presence of aromatic TBS ethers, aliphatic triisopropylsilyl ethers, aliphatic tert-butyl(diphenyl)silyl ethers, or sterically hindered aliphatic TBS ethers. Additionally, TBS ethers can also be transformed into 4-methoxybenzyl ethers or methyl ethers in one pot by using larger quantities of the catalyst and a higher reaction temperature.
- Zhang, Qi,Kang, Xiuqin,Long, Lei,Zhu, Lijuan,Chai, Yonghai
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- Process for producing 1,4-cyclohexanedimethanol
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The present invention relates to a method for manufacturing 1,4-cyclohexane dimethanol having high ratio of trans-1,4-cyclohexane dimethanol. The method for manufacturing 1,4-cyclohexane dimethanol according to an embodiment of the present invention comprises the steps of: obtaining 1,4-cyclohexane dimethanol by hydrogenating 1,4-cyclohexane dicarboxylic acid dialkyl ester; and performing isomerization by heating the 1,4-cyclohexane dimethanol under the presence of a molded catalyst including nickel and a support.COPYRIGHT KIPO 2015
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Paragraph 0058-0061
(2016/12/07)
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- Substituted Imidazopyridines as HDM2 Inhibitors
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The present invention provides substituted imidazopyridines as described herein or a pharmaceutically acceptable salt or solvate thereof. The representative compounds are useful as inhibitors of the HDM2 protein. Also disclosed are pharmaceutical compositions comprising the above compounds and potential methods of treating cancer using the same.
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Paragraph 0708
(2014/07/08)
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- PROCESS FOR THE PREPARATION OF 1,4-CYCLOHEXANEDIMETHANOL FROM TEREPHTHALIC ACID
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Disclosed is a process for the preparation of 1,4-cyclohexanedimethanol from terephthalic acid. Terephthalic acid is esterified with (4-methylcyclohexyl)methanol and the terephthalate ester hydrogenated to 1,4-cyclohexanedimethanol in a 2-stage process. The (4-methylcyclohexyl)methanol that is formed during the hydrogenation step is recycled to the esterification reaction. Also disclosed is a method for purifying and recovering the 1,4-cyclohexanedimethanol product.
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Paragraph 0118
(2013/03/26)
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- INTEGRATED PROCESS FOR THE PREPARATION OF 1,4-CYCLOHEXANEDIMETHANOL FROM TEREPHTALIC ACID
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Disclosed is an integrated process for the preparation of 1,4-cyclohexanedimethanol from terephthalic acid. Terephthalic acid is esterified with (4-methylcyclohexyl)methanol and the terephthalate ester hydro genated to 1,4-cyclohexanedimethanol in a 2-stage process. The (4-methylcyclohexyl)methanol that is formed during the hydrogenation step is recycled to the esterification reaction. Also disclosed is a method for purifying and recovering the 1,4-cyclohexanedimethanol product.
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Paragraph 0108
(2013/03/26)
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- PROCESS FOR THE PREPARATION OF 1,4-CYCLOHEXANEDIMETHANOL
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Disclosed is a process for the preparation of 1,4-cyclohexanedimethanol from terephthalic acid. Terephthalic acid is esterified with (4-methylcyclohexyl)methanol and the terephthalate ester hydrogenated to 1,4-cyclohexanedimethanol in a 2-stage process. The (4-methylcyclohexyl)methanol that is formed during the hydrogenation step is recycled to the esterification reaction. After removal of the (4- methylcyclohexyl)methanol from the crude hydrogenation product, the 1,4- cyclohexanedimethanol product can be recovered and purified by a phase separation and distillation.
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Paragraph 0102
(2013/03/26)
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- Rhodium nanoparticles entrapped in boehmite nanofibers: Recyclable catalyst for arene hydrogenation under mild conditions
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A new recyclable rhodium catalyst was synthesized by a simple procedure from readily available reagents, which showed high activities in the hydrogenation of various arenes under 1 atm H2 at room temperature. The Royal Society of Chemistry 2005.
- Park, In Soo,Kwon, Min Serk,Kim, Namdu,Lee, Jae Sung,Kang, Kyung Yeon,Park, Jaiwook
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p. 5667 - 5669
(2007/10/03)
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- Photoinduced electron transfer of carbazole-acceptor dyads in solution and in a polymer solid
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Photoinduced charge separation (CS) of carbazole-acceptor dyads (Cz-S-A) in solutions and in a polymer solid was examined by the measurement of fluorescence decay. For the discussion of CS from the viewpoint of thermal fluctuations in a solution and in a polymer solid, the separation distance between the Cz donor moiety and acceptor moiety was fixed with a rigid spacer. The photoinduced CS was observed for various solutions with different dielectric constants ranging from 3.06 to 37.5 at room temperature. The rate constant kCS increased with an increase in the free energy gap of -ΔGCS, indicating that CS is in the normal region of the Marcus theory. The temperature dependence of CS in a solution from 183 to 296 K was quantitatively explained by an electron transfer (ET) formula where solvent motions are treated as a classical mode and vibrational motions of the reactant are treated as a quantum mode. On the other hand, the photoinduced CS was also observed for a polymer solid with polar cyano groups over a wide temperature range from 100 to 400 K, although most motions are highly restricted compared with those in a solution. Above the glass transition temperature (T g), CS was explained by the same ET formula as that in a solution with dielectric constants measured at a high frequency. Below Tg, CS was independent of temperature, indicating that CS is caused by nuclear tunneling at low temperatures.
- Ohkita, Hideo,Benten, Hiroaki,Anada, Arihiro,Noguchi, Hitoshi,Kido, Nobuaki,Ito, Shinzaburo,Yamamoto, Masahide
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p. 3977 - 3984
(2007/10/03)
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- Heterocycle derivatives and drugs
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There is provided an excellent novel analgesic having an analgesic effect which is effective widely against a pain including a chronic pain or an allodynia accompanied with herpes zoster by acting on a nociceptin receptor. The present invention relates to a compound represented by the following formula: or a salt thereof. In the formula, X and Y are same or different and each represents a nitrogen atom or CH; R1 represents a hydrogen atom or alkyl and the like; A1 and A2 are same or different and each represents a single bond or a divalent aliphatic hydrocarbon group; Q represents a single bond, cycloalkylene group, phenylene group or divalent heterocyclic group; R2A, R2B, R2C and R2D are same or different and each represents a hydrogen atom, alkyl or phenyl; E represents a ethenylene group or —NRCO— (in which R is hydrogen or alkyl) and the like; R3 represents a phenyl group or a heterocyclic group; R4 and R5 are same or different and each represents a hydrogen atom, alkyl, alkoxy, aralkyloxy, halogen, nitro, hydroxy, alkoxycarbonyl, —NR6R7 (in which R6 and R7 are same or different and each represents a hydrogen atom or alkyl) and the like.
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- Mild and convenient method for reduction of aliphatic and aromatic carboxylic acids and anhydrides with (pyridine)(tetrahydroborato)zinc complex as a new stable ligand-metal tetrahydroborate agent
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Structurally different aliphatic and aromatic carboxylic acids and anhydrides are efficiently reduced to their corresponding alcohols with a new modified zinc tetrahydroborate agent, (pyridine)(tetrahydroborato)zinc complex, [(Py)Zn(BH4)2], in refluxing THF.
- Zeynizadeh, Behzad,Zahmatkesh, Karam
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p. 522 - 525
(2007/10/03)
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- Intramolecular Cyclization of 4-[3-(Trimethylsilyl)prop-1-en-1-yI]-cyclohexanecarbaldehyde with Loss of Formyl Carbon
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Treatment of cis- and trans-4-[3-(trimethylsilyl)prop-1-en-1-yl]cydohexanecarbaldehyde (2a and 2b) with tetrabutylammonium fluoride in dilute tetrahydrofuran afforded 7-vinylbicyclo(2.2.1]heptan-1-ol (3), the same product obtained from 4-[3-(trimethylsilyl)prop-1-en-1-yl]cyclohexanone (1). It was found that oxidative deformyhition of 2a, b to 1 takes place under basic conditions before the cyclization to 3. It was also shown that cyclization of allylsilane with carbonyl does not proceed via an eclipsed conformation.
- Kuroda, Chiaki,Murase, Atsushi,Suzuki, Hideyuki,Endo, Toru,Anzai, Shuzo
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p. 1639 - 1647
(2007/10/03)
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- Lipase-mediated route to diastereo-pure tranexamic acid
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Diastereomerically pure tranexamic acid has been prepared via a diastereomeric separation of a trans-/cis-mixture of 1,4-cyclohexanedimethanol using lipase PS (Pseudomonas sp. Amano).
- Watanabe,Hasegawa,Hiroya,Ogasawara
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p. 529 - 531
(2007/10/02)
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