- Method for preparing lactate
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The invention relates to a method for preparing lactate. The method comprises the following steps of: contacting sugar and alcohol with a catalyst in a reactor, and reacting to obtain a lactate-containing product, wherein the molar ratio of the sugar to the alcohol is 1:(50-900), the reaction temperature is 150-250 DEG C, the reaction time is 10-50 hours, the catalyst contains a mixture of a titanium-silicon molecular sieve and a tin-silicon molecular sieve, and the weight ratio of the sugar to the mixture of the titanium-silicon molecular sieve and the tin-silicon molecular sieve based on drybasis weight is 1:(0.1-6). The method provided by the invention has high sugar conversion rate and high lactate yield.
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Paragraph 0090-0091
(2020/06/30)
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- Method for preparing lactate
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The invention relates to a method for preparing lactate. The method comprises the following steps: contacting pyruvic aldehyde and alcohol with a catalyst in a reactor, and reacting to obtain a lactate-containing product, wherein the molar ratio of the pyruvic aldehyde to the alcohol is 1:(20-225), the reaction temperature is 30-180 DEG C, the reaction time is 1-10 hours, the catalyst contains a mixture of a titanium-silicon molecular sieve and a tin-silicon molecular sieve, and the weight ratio of the pyruvic aldehyde to the mixture of the titanium-silicon molecular sieve and the tin-siliconmolecular sieve based on dry basis weight is 1:(0.1-6). The method provided by the invention has high pyruvic aldehyde conversion rate and high lactate yield.
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Paragraph 0090-0091
(2020/06/30)
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- Retention Characteristics and Sorption Enthalpies of Esters of Natural Hydroxycarboxylic Acids on DB-1 Stationary Phase
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Abstract: Sorption characteristics and retention of esters of glycolic, lactic, malic, and tartaric acids with C1?C8 alcohols of linear structure are studied by gas-liquid chromatography in the temperature range of 90?260°C on DB-1 nonpolar phase. The values of the retention indices of the compounds studied are obtained. On the basis of experimentally determined retention times, the thermodynamic characteristics of sorption under the conditions of limiting dilution are estimated. The dependences of the change in sorption enthalpies on the length of the linear alkyl substituent and on the value of the logarithmic retention index are found. The possibility of estimating the energy of intermolecular interactions of lactic acid esters in the liquid phase is shown on the basis of the obtained values of sorption enthalpies and vaporization enthalpies.
- Portnova,Yamshchikova, Yu. F.,Krasnykh
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p. 577 - 583
(2019/06/03)
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- MONOMER, POLYMER, RESIST COMPOSITION, AND PATTERNING PROCESS
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A polymer comprising recurring units derived from a (meth)acrylate monomer of tertiary ester type having branched alkyl on alicycle is used to form a resist composition. When subjected to exposure, PEB and organic solvent development, the resist composition is improved in dissolution contrast.
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- Development of lactic ester as bifunctional additive of methanol-gasoline
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In this paper, lactic esters were synthesized and used as phase stabilizer and saturation vapor pressure depressor of methanol-gasoline. The results show that the stabilities of the methanol-gasoline depend on the length of the lactic esters' alkoxy group. Several lactic esters were found to be effective in various gasoline-methanol blends, and the lactic esters display high capacity to depress the saturation vapor pressure of methanol-gasoline. According to the results, it can be concluded that the lactic esters have the great potential to be bifunctional gasoline-methanol additives.
- Zhang, Jie,Yang, Changchun,Tang, Ying,Xu, Lianghong,Wang, Xiaoting
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p. 4827 - 4829
(2014/12/10)
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- Lipase-catalyzed oligomerization and hydrolysis of alkyl lactates: Direct evidence in the catalysis mechanism that enantioselection is governed by a deacylation step
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Lipase-catalyzed oligomerization of alkyl d-and l-lactate monomers (RDLa and RLLa, respectively) was studied for the first time. It has been found that the oligomerization occurs enantioselectively only for d-lactates to give oligomers up to heptamers of lactic acid (LA) in good to high yields by using primary C1 to C8 alkyl groups and sec-butyl group for d-lactate monomers. No reaction happened for all l-lactates in similar conditions. Lipase-catalyzed hydrolysis of alkyl d-and l-lactates was also examined, revealing that the hydrolysis took place for both d-and l-lactates, although l-lactates proceeded a couple of times slower. The hydrolysis results clearly demonstrate that the lipase catalysis mechanism involves an acyl-enzyme intermediate (EM) formation via the acylation step from both d-and l-lactates as a rate-determining step, and the subsequent deacylation step, a nucleophilic attack of water to the EM, takes place to produce free LA. On the other hand, in the oligomerization of d-lactates, the deacylation step, in which a sec-alcohol group of the monomer or of the propagating chain-end attacks to the EM, is only allowed for the sec-d-alcohol group to give a one-LA-unit-elongated oligomer. l-Lactates form the EM; however, the subsequent deacylation reaction with both the sec-l-and sec-d-alcohol groups does not take place, failing in the oligomerization to occur. These results provide with the first direct evidence in the lipase catalysis that the enantioselection is governed by the deacylation step. In the co-oligomerization between l-and d-lactates, the l-isomer retarded the reaction rate of the d-isomer, which was found due to the function of the former as a competitive inhibitor in the acylation step toward the latter.
- Ohara, Hitomi,Onogi, Akihisa,Yamamoto, Masafumi,Kobayashi, Shiro
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experimental part
p. 2008 - 2015
(2011/03/22)
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- Picolinic acid as a partner in the Mitsunobu reaction: Subsequent hydrolysis of picolinate esters under essentially neutral conditions with copper acetate in methanol
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The use of picolinic acid and 6-methyl picolinic acid in the Mitsunobu reaction has been studied. These substrates are excellent partners in the Mitsunobu reaction, and offer the added advantage that the resulting esters can be cleaved under essentially neutral conditions using Cu(OAc)2 and methanol.
- Sammakia, Tarek,Jacobs, Jon S.
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p. 2685 - 2688
(2007/10/03)
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