16450-41-2Relevant articles and documents
Stereoretentive N-Arylation of Amino Acid Esters with Cyclohexanones Utilizing a Continuous-Flow System
Ichitsuka, Tomohiro,Komatsuzaki, Shingo,Masuda, Koichiro,Koumura, Nagatoshi,Sato, Kazuhiko,Kobayashi, Shū
supporting information, p. 10844 - 10848 (2021/05/31)
The N-arylation of chiral amino acid esters with minimal racemization is a challenging transformation because of the sensitivity of the α-stereocenter. A versatile synthetic method was developed to prepare N-arylated amino acid esters using cyclohexanones as aryl sources under continuous-flow conditions. The designed flow system, which consists of a coil reactor and a packed-bed reactor containing a Pd(OH)2/C catalyst, efficiently afforded the desired N-arylated amino acids without significant racemization, accompanied by only small amounts of easily removable co-products (i. e., H2O and alkanes). The efficiency and robustness of this method allowed for the continuous synthesis of the desired product in very high yield and enantiopurity with high space-time yield (74.1 g L?1 h?1) and turnover frequency (5.9 h?1) for at least 3 days.
Pemetrexed disodium intermediate and preparation method thereof
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Paragraph 0043-0045, (2019/10/17)
The invention belongs to the technical field of medicine synthesis, and particularly relates to a pemetrexed disodium intermediate II-1 and a preparation method thereof. The preparation method includes the steps: taking 4-[2-(2-amino-4, 7-dihydro-4-oxygen
Characterization and cytotoxicity evaluation of biocompatible amino acid esters used to convert salicylic acid into ionic liquids
Moshikur, Rahman Md.,Chowdhury, Md. Raihan,Wakabayashi, Rie,Tahara, Yoshiro,Moniruzzaman, Muhammad,Goto, Masahiro
, p. 31 - 38 (2018/05/28)
The technological utility of active pharmaceutical ingredients (APIs) is greatly enhanced when they are transformed into ionic liquids (ILs). API-ILs have better solubility, thermal stability, and the efficacy in topical delivery than solid or crystalline drugs. However, toxicological issue of API-ILs is the main challenge for their application in drug delivery. To address this issue, 11 amino acid esters (AAEs) were synthesized and investigated as biocompatible counter cations for the poorly water-soluble drug salicylic acid (Sal) to form Sal-ILs. The AAEs were characterized using 1H and 13C NMR, FTIR, elemental, and thermogravimetric analyses. The cytotoxicities of the AAE cations, Sal-ILs, and free Sal were investigated using mammalian cell lines (L929 and HeLa). The toxicities of the AAE cations greatly increased with inclusion of long alkyl chains, sulfur, and aromatic rings in the side groups of the cations. Ethyl esters of alanine, aspartic acid, and proline were selected as a low cytotoxic AAE. The cytotoxicities of the Sal-ILs drastically increased compared with the AAEs on incorporation of Sal into the cations, and were comparable to that of free Sal. Interestingly, the water miscibilities of the Sal-ILs were higher than that of free Sal, and the Sal-ILs were miscible with water at any ratio. A skin permeation study showed that the Sal-ILs penetrated through skin faster than the Sal sodium salt. These results suggest that AAEs could be used in biomedical applications to eliminate the use of traditional toxic solvents for transdermal delivery of poorly water-soluble drugs.
Synthesis and evaluation of novel sulfenamides as novel anti Methicillin-resistant Staphylococcus aureus agents
Shang, Jian-Li,Guo, Hui,Li, Zai-Shun,Ren, Biao,Li, Zheng-Ming,Dai, Huan-Qin,Zhang, Li-Xin,Wang, Jian-Guo
supporting information, p. 724 - 727 (2013/02/25)
A total of 29 novel sulfenamide compounds were synthesized, spectroscopically characterized and evaluated in vitro for antimicrobial activity against various infectious pathogens. Compounds 1b and 2c exhibited potent inhibition against clinical Methicillin-resistant Staphylococcus aureus (MRSA) strains with minimum inhibitory concentration (MIC) values of 1.56 μg/mL.
A highly efficient flow reactor process for the synthesis of N-Boc-3,4-dehydro-l-proline methyl ester
Tamborini, Lucia,Conti, Paola,Pinto, Andrea,Micheli, Carlo De
experimental part, p. 222 - 225 (2010/05/02)
The multi-step preparation of N-Boc-3,4-dehydro-l-proline methyl ester using a modular flow reactor is reported. The use of immobilised reagents and scavengers in pre-packed glass tubes allows us to obtain the pure product in 87% overall yield, 97% purity, and >98% enantiomeric excess without any additional purification step. Our flow-based protocol enables the rapid multi-gram synthesis (about 9 g/12 h) of the desired product.
Practical synthesis of the C-1027 aminosugar moiety
Hirai, Keiichiro,Tamura, Yukio,Sato, Itaru,Hirama, Masahiro
supporting information; scheme or table, p. 2156 - 2158 (2010/11/02)
A concise and reliable synthetic route to the aminosugar moiety of the C-1027 chromophore was developed. The aminosugar moiety was synthesized from l-glutamic acid in 11 steps and 13% overall yield.
A simple modular synthesis of pyridinoline a collagen cross-link of biochemical interest
Allevi, Pietro,Anastasia, Mario
, p. 2005 - 2012 (2007/10/03)
A simple convergent synthesis of the collagen cross-link pyridinoline starting from glycine is reported.
Synthesis and anticholinesterase activity of some benzo-1,3,2-dioxaphospholene, oxazaphospholine and diazaphospholine 2-ones containing 2-amino acid substitution
Ali, Hussein M.
, p. 157 - 166 (2007/10/03)
Synthesis of the titled compounds has been described. 1H NMR, IR band frequencies and MS fragmentation and rearrangement peaks were analyzed and discussed in detail. Studying the inhibitory effect of these compounds on acetylcholinesterase (AChE) showed that dioxaphospholenes were stronger inhibitors than oxazaphospholines and diazaphospholines. This was explained by increasing the number of nitrogen atoms around the phosphorus atom in the later two series, which reduces the electrophilic character of the phosphorus atom by the overlapping between the dπ - pπ orbitals of the phosphorus and the neighboring nitrogen atoms, and hence reducing the electrophilic attack of the phosphorus atom on a nucleophilic center at the esteratic site of the enzyme. Steric factor of the amino acid moiety showed stronger effect than the electronic factor on the inhibition activity, the observed order was glycine > glutamic > methaionine > phenylalanine > alanine.
Water soluble 3,5-diacetamido-2,4,6-triiodobenzoic acid derivatives
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, (2008/06/13)
The invention relates to novel water soluble 3,5-diacetamido-2,4,6-triiodobenzoic acid derivatives, the method for making the same and their use as X-ray contrast agents for vasography, urography, myelography, artrography, fistulography and salpingography.