- Method for preparing 1, 3-cyclohexanedione
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The invention discloses a method for preparing 1, 3-cyclohexanedione. The method comprises the following steps: 1) dissolving acetylacetone and a catalyst in a solvent, adding acrylate into a constant-pressure dropping funnel, and dropwise adding acrylate into a reaction system, after drop-by-drop adding, heating to 60-80 DEG C, and continuously reacting for 0.5-1 hour; and 2) after the reaction is finished, cooling to 40 DEG C, adding a solid condensing agent, heating the reaction liquid to 40-50 DEG C, continuously reacting for 1-1.5 hours, concentrating under reduced pressure to remove the solvent and methyl acetate and other low-boiling-point byproducts generated by the reaction, then adding a small amount of water, adjusting the pH value to 1-2 by using hydrochloric acid (1.1-1.2 equivalent), cooling to separate out a product, centrifuging, leaching by using a small amount of ice water, carrying out pulping treatment by using ethyl acetate, filtering and drying to obtain the 1, 3-cyclohexanedione product.
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Paragraph 0026-0031
(2021/09/04)
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- Preparation method of delta-caprolactone
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The invention relates to a preparation method of delta-caprolactone. The method comprises the following steps: dissolving a beta-dicarbonyl compound and a basic catalyst in a solvent, and conducting preheating; dropwise adding alkyl acrylate into a reaction system for a Michael addition reaction; cooling the system, adding alkali, and then heating the reaction system for saponification reaction; adding water, cooling the system, and adding a reducing agent for reaction; and cooling the system, adjusting the pH value with acid, and carrying out post-treatment to obtain the delta-caprolactone. The method disclosed by the invention is simple in process operation, high in safety, high in raw material utilization rate, short in total consumed time and free of generation of carbon dioxide.
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Paragraph 0064; 0083-0084; 0086-0087; 0089-0092
(2021/08/25)
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- Design and synthesis of high affinity inhibitors of Plasmodium falciparum and Plasmodium vivax N-myristoyltransferases directed by ligand efficiency dependent lipophilicity (LELP)
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N-Myristoyltransferase (NMT) is an essential eukaryotic enzyme and an attractive drug target in parasitic infections such as malaria. We have previously reported that 2-(3-(piperidin-4-yloxy)benzo[b]thiophen-2-yl)-5-((1,3, 5-trimethyl-1H-pyrazol-4-yl)meth
- Rackham, Mark D.,Brannigan, James A.,Rangachari, Kaveri,Meister, Stephan,Wilkinson, Anthony J.,Holder, Anthony A.,Leatherbarrow, Robin J.,Tate, Edward W.
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supporting information
p. 2773 - 2788
(2014/04/17)
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- Carbon dioxide as a reversible amine-protecting agent in selective Michael additions and acylations
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Carbon dioxide can be used as a temporary protecting group for amines. A carbamic acid is formed reversibly when CO2 is bubbled through a solution of a sufficiently basic primary amine at room temperature and atmospheric pressure. This reaction is employed for the protection of the amine functionality in several reactions at room temperature where inter- or intramolecular selectivity is desired. The concept is demonstrated for the selective Michael additions to methyl acrylate of a normally less reactive sulfonamide in the presence of a strong amine nucleophile, or of a cyclic secondary amine in the presence of an aliphatic primary amine, or of a β-ketoester in the presence of amines. The selective acylation of an alcohol in the presence of an amine can be achieved under a CO2 atmosphere as well.
- Peeters, Annelies,Ameloot, Rob,De Vos, Dirk E.
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p. 1550 - 1557
(2013/09/24)
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- Poly(N-vinylimidazole) as efficient recyclable catalyst for the Michael addition of CH-acids to electron deficient alkenes in water
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Efficiency of poly(N-vinylimidazole) as the basic recyclable catalyst for the Michael addition of CH-acids to acrylonitrile, methyl acrylate, methyl vinyl ketone and methyl vinyl sulfone in water at ambient temperature was studied. In these reactions, formation of both 1 : 1 and 1 : 2 adducts is possible.
- Tarasenko, E. A.,Beletskaya, I. P.,Tyurin, V. S.,Lamaty, F.
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p. 2613 - 2616,4
(2020/09/16)
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- Synthetic porphyrins bearing β-propionate chains as photosensitizers for photodynamic therapy
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Porphyrins with different numbers of β-propionate chains mimicking natural porphyrins were prepared via the 2+2 MacDonald type approach. Photodynamic activity against WiDr colon adenocarcinoma cells showed that activity is related to the number of β-propi
- Pereira, Nelson,Serra, Arménio C.,Pineiro, Marta,Gonsalves, António M. D'A. Rocha,Abrantes, Margarida,Laranjo, Mafalda,Botelho, Filomena
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experimental part
p. 438 - 445
(2010/12/18)
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- Process For Preparing Porphyrin Derivatives, Such As Protoporphyrin (IX) And Synthesis Intermediates
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The present invention relates to a process for preparing a porphyrin of formula (I), optionally in the form of a salt with an alkali metal and/or in the form of a metal complex: in which: R and R′ are as defined in claim 1, comprising: a step of condensation, in an acidic medium, between a dipyrromethane of formula (II): in which R′b is as defined above for (I), and a dipyrromethane of formula (III): in which R″ is as defined in claim 1, and also the compounds of formula (III).
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Page/Page column 14-15
(2008/12/07)
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- Fast carbon-carbon bond formation by a promiscuous lipase
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Lipase B from Candida antarctica was redesigned to catalyze the promiscuous reaction of carbon-carbon bond formation. Mutation of the catalytic serine to alanine afforded a mutant that catalyzed Michael additions of 1,3-dicarbonyls to α,β-unsaturated carbonyl compounds at high specific rates, such as 4000 s-1. The enzyme-catalyzed Michael addition reaction followed saturation kinetics and showed substrate inhibition. The designed enzyme showed high rate enhancements with a catalytic proficiency higher than 108, which is on the same level as that observed for enzymes with native substrates. Copyright
- Svedendahl, Maria,Hult, Karl,Berglund, Per
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p. 17988 - 17989
(2007/10/03)
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- Synthesis of a new lipophilic bilirubin. Conformation, transhepatic transport and glucuronidation
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Analogs of symmetrical bilirubin isomers with vinyl groups replaced by n-butyls (1 and 2) were synthesized and found to be much more soluble in nonpolar solvents than either bilirubin itself or its analogs with ethyls in place of vinyls (3 and 4). The increased lipophilicity of 1 and 2 allowed, for the first time, vapor pressure osmometric molecular wt. determinations of a bilirubin acid, showing in CHCl3 solvent: MW(obs)=632±10 for 1, and 637±10 for 2 (both formula weight 644) - data that clearly indicate monomers and no dimers. The induced circular dichroism (ICD) spectra of 1 and 2, with negative exciton chirality Cotton effects, are quite like those of 3 and 4 in chloroform containing quinine, but the ICDs in aqueous buffer containing human serum albumin differ considerably. Rubins 1, 3 and 4 exhibit dissimilar but positive exciton chirality Cotton effects, while 2 shows a negative exciton chirality Cotton effect. The metabolism of the n-butyl rubins in the rat is highly dependent on the specific endo or exo location of the n-butyl groups. Rubin 2, with two endo n-butyl groups was metabolized rather like the corresponding mesobilirubin (4) or natural bilirubin itself, being converted to a mono and diglucuronide that were excreted promptly in bile. The presence of the bulky endo-n-butyl groups and the high lipophilicity of the compound seemed to interfere with glucuronidation in the liver only slightly. In contrast, the similar, yet even more lipophilic n-butyl rubin 1, which has two exo n-butyl groups, was glucuronidated and excreted in bile in the rat rather poorly. (C) 2000 Elsevier Science Ltd.
- Brower, Justin O.,Lightner, David A.,McDonagh, Antony F.
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p. 7869 - 7883
(2007/10/03)
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- Synthesis of Vinca Alkaloids and Related Compounds. 90.1 New Results in the Synthesis of Alkaloids with the Aspidospermane Skeleton. First Total Synthesis of (±)-3-Oxominovincine
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The tryptamine derivative 1 readily reacted with methyl 4-acetyl-5-bromopent-4-enoate (9) that had been built up from 2,4-pentanedione. On intramolecular dehydration and subsequent [4 + 2] cycloaddition, the reaction product 10 gave the epimers 12 and 13 having the D-secoaspidospermane skeleton. Compound 12 directly and 13 after epimerization yielded (±)-3-oxominovincine (14). Regioselective reduction of 14 furnished (±)-minovincine (17).
- Kalaus, Gy?rgy,Juhász, Imre,Greiner, István,Kajtár-Peredy, Mária,Brlik, János,Szabó, Lajos,Szántay, Csaba
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p. 9188 - 9191
(2007/10/03)
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- ALKYLATION OF CH ACIDS IN THE PRESENCE OF POTASSIUM CARBONATE. IV. ALKYLATION OF 2,4-PENTANEDIONE AND 3-METHYL-2,4-PENTANEDIONE
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The reaction of 2,4-pentanedione and 3-methyl-2,4-pentanedione with ethyl acrylate in the presence of potassium carbonate gave the Michael adducts.The acylotropic rearrangement of the products from the reaction of 3-methyl-2,4-pentanedione with ethyl α-bromoacrylate and dibromoethane under the influence of potassium carbonate was investigated.
- Khachatryan, D. S.,Vardapetyan, A. A.,Panosyan, G. A.,Mirzoyan, R. G.,Morlyan, N. M.
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p. 1806 - 1810
(2007/10/02)
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- The Chemistry of Pyrrolic Compounds. XLII. The Synthesis of Some Diacetyldeuteroporphyrins as Intermediates in the Preparation of the Isomeric Protoporphyrins: a Comparative Spectroscopic Study of the Diacetyldeuteroporphyrins
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A range of isomeric diacetyldeuteroporphyrins has been synthesized by the oxidative cyclization of appropriately substituted bilenes-b, and the electronic and n.m.r. spectra of these porphyrins have been studied.As a result it has been shown that the relative position of the two acetyl groups influences the absorption pattern of the visible spectrum more precisely than was previously appreciated.In consequence, it is possible to recognize the 1,4 2,3 and 2,4 relative distribution of the acetyl groups by an examination of the electronic spectrum.In addition, it is clear that the acetyl groups present in this series of porphyrins affect the chemical shift of all the methine protons and not only the one which is directly adjacent to the carbonyl function.
- Clezy, Peter S.,Fookes, Christopher J. R.
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p. 545 - 556
(2007/10/02)
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