- ANTIVIRAL COMPOUNDS
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The present disclosure provides compounds for treating a variety of diseases, such as respiratory syncytial virus (RSV), HRV, hMPV, ebola, Zika, West Nile, Dengue, and HCV.
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Paragraph 0528
(2021/08/27)
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- A practical access to new pyrrolizine carboxylates via KHMDS-catalyzed carbocyclizations
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Easy and effective preparation of new 1H-pyrrolizine carboxylates was achieved with high efficiency via KHMDS-induced carbocyclization of N-alkynyl proline carboxylates under substantially mild conditions. Meanwhile, some trans-diiodoallylic N-proline carboxylates were obtained from N-propargyl proline carboxylates using molecular I2 with or without KHMDS. This method is quite feasible in terms of practical and quick access to the pyrrolizines and their derivatives over the formation of carbanions.
- Yildirim, Muhammet,Suleiman, Garba
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supporting information
p. 463 - 481
(2019/01/25)
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- A (1 R, 3 S) -3 - amino-cyclopentanol hydrochloride preparation method (by machine translation)
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The invention discloses a (1 R, 3 S) - 3 - amino-cyclopentanol hydrochloride of the preparation method, the method using chiral carboxylic acid with hydroxylamine to form the amide as chiral source, in copper catalyzed oxidation in the reaction system to rapidly obtain a chiral Diels - alder reaction product, after passes through the reduction reaction and alkaline deprotection reaction, and acidified after reaction to obtain the target product. Chiral inducing reagent chiral carboxylic acid by simple acidification, extraction processing can be reclaimed and reused. This kind of (1 R, 3 S) - 3 - amino-cyclopentanol hydrochloride preparation method has high operation safety and high selectivity, raw materials are easy, and the cost is low, the reaction time is short and simple process flow and the like. (by machine translation)
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Paragraph 0034
(2019/05/08)
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- Characterization and cytotoxicity evaluation of biocompatible amino acid esters used to convert salicylic acid into ionic liquids
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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.
- Moshikur, Rahman Md.,Chowdhury, Md. Raihan,Wakabayashi, Rie,Tahara, Yoshiro,Moniruzzaman, Muhammad,Goto, Masahiro
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- The reactions of α-amino acids and α-amino acid esters with high valent transition metal halides: synthesis of coordination complexes, activation processes and stabilization of α-ammonium acylchloride cations
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Titanium tetrachloride smoothly reacted with a selection of α-amino acids (aaH) in CH2Cl2 affording yellow to orange solid coordination compounds, 1a-d, in 70-78% yields. The salts [NHEt3][TiCl4(aa)], 2a-b, were obtained from TiCl4/aaH/NEt3 (aa = l-phenylalanine, N,N-dimethylphenylalanine), in 60-65% yields. The complex , 3, was isolated from the reaction of l-proline with NbCl5/NHiPr2, performed in CH2Cl2 at room temperature. The X-ray structure of 3 features a bridging (E)-1,2-bis(3,4-dihydro-2H-pyrrol-5-yl)ethene-1,2-diolate ligand, resulting from the unprecedented C-C coupling between two proline units. Unusually stable α-ammonium acyl chlorides were prepared by the reactions of PCl5/MCln (MCln = NbCl5, WCl6) with l-proline, N,N-dimethylphenylalanine, sarcosine and l-methionine. MX5 (M = Nb, Ta; X = F, Cl) reacted with l-leucine methylester and l-proline ethylester to give ionic coordination compounds, [MX4L2][MX6] (M = Nb, L = Me2CHCH2CH(NH2)CO2Me, X = F, 9; Cl, 11a; M = Nb, X = Cl, , 11c; Ta, 11d), in moderate to good yields. [NbCl5(Me2CHCH2CHNH3CO2Me)][NbCl6], 12, was isolated as a co-product of the reaction of NbCl5 with l-leucine isopropylester, and crystallographically characterized. The reaction of NbCl5 with l-serine isopropylester afforded NbCl3(OCH2CHNHCO2iPr), 13, in 66% yield. The activation of the ester O-R bond was observed in the reactions of l-leucine methyl ester with NbF5 and l-proline ethyl ester with MBr5 (M = Nb, Ta), these reactions proceeding with the release of EtF and EtBr, respectively. All the metal products were characterized by analytical and spectroscopic methods, while DFT calculations were carried out in order to provide insight into the structural and mechanistic aspects.
- Biancalana, Lorenzo,Bortoluzzi, Marco,Ferretti, Eleonora,Hayatifar, Mohammad,Marchetti, Fabio,Pampaloni, Guido,Zacchini, Stefano
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p. 10158 - 10174
(2017/02/15)
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- Proline ester hydrochloride preparation method (by machine translation)
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The invention discloses a proline ester hydrochloride of the preparation method, comprising the following steps: 1), the initial reaction, sequentially carrying out the following steps: (1), the proline, solvent, pyridines in catalyst are put into a container, then hydrogen chloride gas, reacting at room temperature production proline hydrochloride; (2), which comprises the steps are put into a container in the after, continue to hydrogen chloride gas, the reaction is carried out at the reflux temperature, steaming and reaction solution, recrystallization cooling to separate out the solid, the solvent for washing, filtering, drying filter cake, shall be proline ester hydrochloride; filtrate and steaming and, as a next cycle of the mother liquor; 2), recycled: step (1) is changed to account for the solvent in the step (1) 0.5 - 0.7 times of the volume of the solvent, in order to step 1) the resulting mother liquor in step (1) substituted pyridines catalyst, the remaining the same steps 1), to proline ester hydrochloric acid salt, thereby realizing the recycled. (by machine translation)
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Paragraph 0031; 0032; 0033; 0034; 0035; 0036; 0037-0054
(2017/05/16)
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- Synthesis of a series of amino acid derived ionic liquids and tertiary amines: Green chemistry metrics including microbial toxicity and preliminary biodegradation data analysis
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A series of l-phenylalanine ionic liquids (ILs), l-tyrosine ILs, tertiary amino analogues and proposed transformation products (PTPs) have been synthesised. Antimicrobial toxicity data, as part of the green chemistry metrics evaluation and to supplement preliminary biodegradation studies, was determined for ILs, tertiary amino analogues and PTPs. Good to very good overall yields (76 to 87%) for the synthesis of 6 ILs from l-phenylalanine were achieved. A C2-symmetric IL was prepared from TMS-imidazole in a one-pot two-step method in excellent yield (91%). Synthesis of the l-tyrosine IL derivatives utilised a simple protection group strategy by using an extra equivalent of the bromoacetyl bromide reagent. Improvements in the synthesis of the α-bromoamide alkylating reagent from l-phenylalanine were achieved, directed by green chemistry metric analysis. A solvent switch from dichloromethane to THF is described, however the yield was 15% lower. Antimicrobial activity testing of l-phenylalanine ILs, l-tyrosine ILs, tertiary amino analogues and PTPs, against 8 bacteria and 12 fungi strains, showed that no compound had a high antimicrobial activity, apart from an l-proline analogue. In this exceptional case, the highest toxicity (IC95 = 125 and 250 μM) was observed towards the two Gram positive strains Staphylococcus aureus and Staphylococcus epidermidis respectively. High antimicrobial activity was not found for the other bacteria or fungi strains screened. The limitations of the antimicrobial activity study is discussed in relation to SAR studies. Preliminary analysis of biodegradation data (Closed Bottle Test, OECD 301D) is presented. The pyridinium IL derivative is the preferred green IL of the series based on synthesis, toxicity and biodegradation considerations. This work is a joint study with Kümmerer and co-workers and the PTPs were selected as target compounds based on concurrent biodegradation studies by the Kümmerer group. For the comprehensive biodegradation and transformation product analysis see the accompanying paper.
- Jordan, Andrew,Hai?, Annette,Spulak, Marcel,Karpichev, Yevgen,Kümmerer, Klaus,Gathergood, Nicholas
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supporting information
p. 4374 - 4392
(2016/08/19)
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- SPIRO-LACTAM NMDA RECEPTOR MODULATORS AND USES THEREOF
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Disclosed are compounds having enhanced potency in the modulation of NMDA receptor activity. Such compounds are contemplated for use in the treatment of conditions such as depression and related disorders. Orally available formulations and other pharmaceutically acceptable delivery forms of the compounds, including intravenous formulations, are also disclosed.
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Paragraph 0117
(2014/08/19)
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- Dakin-west reaction of n-thioacylprolines using trifluoroacetic anhydride: Novel access to 5-trifluoromethylthiazoles
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The reaction between N-thioacylprolines and trifluoroacetic anhydride in the presence of pyridine afforded a good yield of 5-trifluoromethylthiazoles. This reaction proceeded through mesoionic 1,3-thiazolium-5-olates, followed by cleavage of the pyrrolidine ring and the formation of thiazoles, introducing a trifluoromethyl group at position 5 in the thiazole ring.
- Hagimoto, Yuri,Saijo, Ryosuke,Kawase, Masami
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p. 709 - 724
(2014/04/03)
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- Cross aldol condensation of acetaldehyde and formaldehyde in the presence of bifunctional systems
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Liquid-phase cross-aldol condensation of acetaldehyde and formaldehyde in the presence of salts of various saturated and unsaturated linear amines, aromatic amines, diamines, and nitrogen bases, as well as in the presence of substituted piperazines, linear and cyclic amino acids and their derivatives, and nitrogen-containing ionic liquids, was studied. The cross-condensation products were formed in considerable amounts when amine hydrochlorides, N-benzoyl amino acids, and amino acid esters were used as catalyst. The formation of cross-condensation products is favored by increased basicity of the amino nitrogen atom in the salt and of the solvent.
- Dashko, L. V.,Dmitriev, D. V.,Pestov, S. M.,Flid, V. R.
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p. 1732 - 1737
(2015/02/05)
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- Enantioselective addition of dialkylzinc reagents to N-(diphenylphosphinoyl)imines catalyzed by β-aminoalcohols with the prolinol skeleton
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Several β-aminoalcohols with the prolinol framework are shown to be very efficient catalysts for the enantioselective addition of dialkylzinc reagents to N-(diphenylphosphinoyl)imines. The use of 0.5 equiv of the catalyst leads to the expected addition products in good yields and with ee up to 94% in a reaction time of only 4 h at room temperature. This ee is the highest value reported so far using 0.5 equiv of an aminoalcohol as a promoter. High enantioselectivities are obtained in the addition of dialkylzincs to both aromatic and aliphatic imines. The amount of the catalyst can be reduced to 0.25 equiv with a slight decrease in the ee. A very interesting effect of the addition rate and temperature on the enantioselectivity was also observed.
- Almansa, Raquel,Guijarro, David,Yus, Miguel
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p. 2828 - 2840
(2008/03/28)
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- Enantioselective reduction of aromatic ketones catalysed by chiral ruthenium(II) complexes
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The catalytic enantioselective reduction of aromatic ketones in 2- propanol is carried out by using ruthenium(II) complexes prepared from [Ru(p- cymene)Cl2]2 and a variety of chiral diamines and β-aminoalcohols derived from α-amino acids. Good conversions (>99%) and enantioselectivities (=96%) are observed under mild reaction conditions. (C) 2000 Elsevier Science Ltd.
- Aitali,Allaoud,Karim,Meliet,Mortreux
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p. 1367 - 1374
(2007/10/03)
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- Synthetic studies towards proline amide isosteres, potentially useful molecules for biological investigations
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2-Ethenylpyrrolidine derivative 8b was prepared from N-protected proline ethyl ester 6b. Bromofluorination of 8b wth NBS-Bu4NF/2HF gave a 1:1 regioisomeric mixture, 9b and 10b (X = Br). Dehydrobromination of 9b and 10b with t-BuOK produced a fluoroolefin 11 and a proline amide isostere model 12, respectively. Deprotection of the Z group in 12 was attempted by treatment with CF3COOH. Although formation of the useful molecule is pseudopeptide synthesis, 13, was observed as checked by NMR spectra, it seemed to decompose slowly during purification procedure to give a mixture of fluorine-free compounds.
- Takeuchi,Yamada,Suzuki,Koizumi
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p. 225 - 232
(2007/10/02)
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- KINETICS OF THE ALKALINE HYDROLYSIS OF SEVERAL N-BENZYLOXYCARBONYLDIPEPTIDE METHYL AND ETHYL ESTERS
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The reaction rates of the alkaline hydrolysis of synthesized N-protected dipeptide methyl and ethyl esters were studied systematically.From the kinetic data the energies of activation, the pre-exponential factors and the reference values at 40 deg C were calculated.The rate of hydrolysis shows to be strongly dependent on the C-terminal amino acid in the sequence Gly >> Ala/Met/Phe > Leu >> Val/Pro.Surprisingly the N-terminal amino acid also exerts an effect, but in a different sequence.N-Terminal Phe in particular shows a relative accelerating effect.Remarkable is the significantly faster ester hydrolysis of glycine containing dipeptide ethyl esters in ethanol/water compared to the corresponding methyl esters in methanol/water.
- Hoogwater, D. A.,Peereboom, M.
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p. 5325 - 5332
(2007/10/02)
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