13248-54-9Relevant articles and documents
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Debabov,V.G.,Shibnev,V.A.
, (1963)
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Configurational Statistics of Poly(cyclohexene carbonate)
Yoshida, Naofumi,Aoki, Daisuke,Sasanuma, Yuji
, p. 9362 - 9374 (2020/11/13)
Conformational characteristics of poly(cyclohexene carbonate) (PCHC) have been investigated via molecular orbital (MO) calculations and NMR experiments on model compounds. The MO energies established through comparison with the NMR experiments were applied to the rotational isomeric state scheme with Bernoulli and Markov stochastic processes to yield configurational properties such as unperturbed characteristic ratio, its temperature coefficient, configurational entropy, tacticity entropy, and coherence number of PCHC chains including various stereosequences. trans-PCHC composed of (R,R)- and/or (S,S)-repeating units prefers a tg+t conformation in the O-CH-CH-O bond sequence of the (R,R)-unit, and its unperturbed characteristic ratio depends considerably on stereoregularity: isotactic, 29, and syndiotactic, 0.83 (in chloroform at 25 °C). cis-PCHC comprising (R,S)- and/or (S,R)-units exclusively adopts either g-g+g+ or g-g-g+ conformation in the O-CH-CH-O bond sequence of the (R,S)-unit partly owing to intramolecular hydrogen bonds, and the dependence of the characteristic ratio of cis-PCHC on stereoregularity would be completely opposite to that of trans-PCHC: isotactic, 0.59, and syndiotactic, 25. In terms of the abovementioned characteristic parameters, properties of PCHCs synthesized so far with stereospecific catalysts are discussed.
Levorotatory meptazinol prodrug as well as preparation method and purpose thereof
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Paragraph 0092; 0094; 0095, (2017/07/19)
The invention provides a levorotatory meptazinol prodrug as well as a preparation method and a purpose thereof, wherein the levorotatory meptazinol prodrug is a compound as shown in a formula I or a stereoisomer, a geometrical isomer, a tautomer, oxynitride, a hydrate, a solvate, a metabolite or a pharmaceutically acceptable salt of the compound as shown in the formula I. The compound is low in hepatic first pass effect and high in bioavailability; a medicine which uses the compound as an active component can be used for treating a neurodegenerative disease or various kinds of acute and chronic pain, such as a wound, postoperative, obstetrical and cancer pain, hemicrania, neuropathic pain and the like.
DEVICE AND PROCESS FOR CONTINUOUS PHOSGENATION
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Page/Page column, (2013/11/19)
A continuous process for generation of phosgene from CO and Cl2 and consumption of the phosgene thus generated in a liquid-phase reaction so as to form organic products P. The process is implemented in two successive reactors R1 and R2, the first reactor R1 being a reactor for catalytic synthesis of phosgene from CO and Cl2 gas, and the second reactor R2 being a piston reactor, the second reactor R2 being equipped with a mechanical axial agitation device.
