- Synthesis method of 3-hydroxy-2-phenylpropionic acid
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The invention discloses a synthetic method of 3-hydroxyl-2-phenylpropionic acid. The method comprises the following steps: mixing dimethyl sulfoxide, paraformaldehyde, potassium carbonate powder and methyl phenylacetate, heating to 85-95 DEG C, carrying out gas phase monitoring reaction, and cooling to room temperature when the GC content of the product methyl tropine is more than or equal to 70%;adjusting the pH value to be neutral, and performing reduced pressure distillation for desolvation; then adding methanol into the desolventized mixture, dropwise adding a sodium hydroxide solution, and reacting to obtain a mixed solution containing sodium tropine salt; adjusting the pH value of the mixed solution to 2-3, and completely reacting to obtain a crude product; and finally, recrystallizing the crude product sequentially by using methylbenzene of which the ratio of m product to m methylbenzene is 1: (4-6), methylbenzene/water of which the ratio of m product to m methylbenzene to m water is 1: (1-2): (4-6), and water of which the ratio of m product to m water is 1: (4-6) to obtain a pure product of 3-hydroxyl-2-phenylpropionic acid. According to the method, GC is adopted to monitor the reaction, control points are judged quickly and accurately, purification of methyl tropinate is not needed, operation procedures are reduced, and production cost is reduced. According to the method, the purity of the prepared 3-hydroxyl-2-phenylpropionic acid reaches 99% or above while the yield is ensured to reach 76.5% or above.
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Paragraph 0024; 0027-0029; 0030; 0032-0035; 0036; 0039-0041
(2019/12/25)
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- Regioselective Copper-Catalyzed Boracarboxylation of Vinyl Arenes
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Regioselective copper-catalyzed boracarboxylation of vinyl arenes with bis(pinacolato)diboron and carbon dioxide has been achieved. New boron-functionalized α-aryl carboxylic acids, including nonsteroidal anti-inflammatory drugs (NSAIDs), are obtained in moderate to excellent yields. The synthetic utility of the transformation was shown through subsequent derivatization of the carbon-boron bond yielding formal hydroxy- and fluorocarboxylation products as well as anionic difluoroboralactones.
- Butcher, Trevor W.,McClain, Edward J.,Hamilton, Tyler G.,Perrone, Trina M.,Kroner, Kayla M.,Donohoe, Gregory C.,Akhmedov, Novruz G.,Petersen, Jeffrey L.,Popp, Brian V.
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p. 6428 - 6431
(2016/12/23)
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- Gold(I)/copper(II)-cocatalyzed tandem cyclization/semipinacol reaction: Construction of 6-Aza/Oxa-Spiro[4.5]decane skeletons and formal synthesis of (±)-halichlorine
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A simple and efficient strategy for the construction of 6-aza/oxa-spiro[4.5]decane skeletons under the cocatalysis of gold(I)/copper(II) was developed, and its potential utility was demonstrated by a formal synthesis of the biologically active marine alkaloid (±)-halichlorine.
- Zhu, Dao-Yong,Zhang, Zhen,Mou, Xue-Qing,Tu, Yong-Qiang,Zhang, Fu-Min,Peng, Jin-Bao,Wang, Shao-Hua,Zhang, Shu-Yu
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p. 747 - 752
(2015/03/18)
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- Selective reductions of cyclic 1,3-diesters by using SmI2 and H2O
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SmI2/H2O reduces cyclic 1,3-diesters to 3-hydroxyacids with no over reduction. Furthermore, the reagent system is selective for cyclic 1,3-diesters over acyclic 1,3-diesters, and esters. Radicals formed by one-electron reduction of the ester carbonyl group have been exploited in intramolecular additions to alkenes. The ketal unit and the reaction temperature have a marked impact on the diastereoselectivity of the cyclizations. Cyclization cascades are possible when two alkenes are present in the starting cyclic diester and lead to the formation of two rings and four stereocenters with excellent stereocontrol.
- Collins, Karl D.,Oliveira, Juliana M.,Guazzelli, Giuditta,Sautier, Brice,De Grazia, Sara,Matsubara, Hiroshi,Helliwell, Madeleine,Procter, David J.
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scheme or table
p. 10240 - 10249
(2010/11/18)
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- An efficient approach to?the?asymmetric total synthesis of?(-)-anisodine
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-Anisodine (l-6,7-epoxy-3-tropyl-α-hydroxytropate), which was isolated from the medicinal plant Scopolia tanguticus Maxim, was the first efficiently prepared using 6-β-acetyltropine as the starting material via a key step of the Sharpless asymmetric dihydroxylation (AD). The intermediate compounds 10 and 11 showed promising cholinergic activity.
- Chang, Junbiao,Xie, Weilin,Wang, Limin,Ma, Nianchun,Cheng, Senxiang,Xie, Jingxi
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p. 397 - 400
(2007/10/03)
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- Stereochemistry of the 1,2-migration of the carboxyl group that occurs during the biosynthesis of tropic acid from phenylalanine
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(2S,3R)- and (2S,3S)-phenylalanine were fed in separate experiments to Datura innoxia plants.The distribution of isotopes in the resultant labeled hyoscyamine and scopolamine indicates that the biosynthesis of the acid moiety of these ester alkaloids, namely (S)-tropic acid, involves the migration of the carboxyl group of phenylalanine to its prochiral C-3 position with retention of configuration.
- Leete, Edward
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p. 226 - 228
(2007/10/02)
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- Contribution to the stability of tropicamide solutions (author's transl)
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The course of the degradation of tropicamide solutions was elucidated. Thus, inter alia, intramolecular elimination of water leads to a compound comparable to apoatropine that the authors designated by atropicamide. Furthermore, methods are described that permit (after thin-layer chromatographic repartition) to detect and to determine quantitatively the active principle in the presence of its degradation products. Tropicamide is stable in aqueous solution; eye-drops prepared from such a solution (Mydrum) are stable for no less than 5 years.
- Pohloudek-Fabini,Martin,Gallasch
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p. 184 - 187
(2007/10/02)
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- Enantiotopically Selective Oxidation of α,ω-Diols with the Enzyme Systems of Microorganisms
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Gluconobacter were found to be capable of oxidizing prochiral diols such as 2-substituted propane-1,3-diols 1 and 3-substituted pentane-1,5-diols 4 with distinction of pro-R and pro-S sites of the molecules, in that (-)-(R)-α-substituted β-hydroxypropionic acids 2 and (+)-(3S)-3-substituted δ-valerolactones 5 were obtained, respectively.Oxidation of 3-methylpentane-1,3,5-triol 11 afforded unnatural (+)-(S)-mevalonolactone 12.The steric bulkiness of the substituents on the prochiral center and the distance from the hydroxy group greatly affected the rate and the enantioselectivity of the reaction.
- Ohta, Hiromichi,Tetsukawa, Hatsuki,Noto, Naoko
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p. 2400 - 2404
(2007/10/02)
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- THE REACTION OF SMALL RING COMPOUND WITH CARBON MONOXIDE. THE CARBONYLATION OF OXIRANE
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The carbonylation of oxiranes catalyzed by rhodium complex afforded β-lactones.Various factors which control the above reaction are presented.
- Kamiya, Yoshio,Kawato, Katsuhito,Ohta, Hiroyuki
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p. 1549 - 1552
(2007/10/02)
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